CleaverBrooks CBLE Operation And Maintenance Manual

Table Of Contents

Compliments of Power Mechanical, Inc.

Used Boilers

Rental Boilers

Model CBLE

Packaged Boiler

250 - 350 HP

Light OIl, Heavy Oil, Gas, or Combination

Operation and Maintenance Manual

750-91

12/09

!

WARNING

DANGER

If the information in this manual is not fol­lowed exactly, a fire or explosion may re­sult causing property damage, personal
injury or loss of life.

— Do not store or use gasoline or other
flammable vapors and liquids in the vicin­ity of this or any other appliance.

— WHAT TO DO IF YOU SMELL GAS

• Do not try to light any appliance.

• Do not touch any electrical switch; do
not use any phone in your building.

• Immediately call your gas supplier
from a neighbor's phone. Follow the
gas supplier's instructions.

• If you cannot reach your gas supplier,
call the fire department.

— Installation and service must be per­formed by a qualified Cleaver-Brooks,
service agency or the gas supplier.

!

WARNING

DANGER

To minimize the possibility of serious personal injury,
fire or damage to the equipment, never violate the fol­lowing safety rules.
— Always keep the area around the boiler free of com­bustible materials, gasoline, and other flammable liq­uids and vapors
— Never cover the boiler, lean anything against it,
stand on it, or in any way block the flow of fresh air to
the boiler.

!

WARNING

DANGER

Improper installation, adjustment, service, or
maintenance can cause equipment damage, per­sonal injury, or death. Refer to the Operation and
Maintenance manual provided with the boiler. In­stallation and service must be performed by a
qualified Cleaver-Brooks service provider.

!

WARNING

DANGER

Be sure the fuel supply which the boiler was de­signed to operate on is the same type as specified
on the boiler name plate.

!

WARNING

DANGER

Should overheating occur or the gas supply valve
fail to shut off, do not turn off or disconnect the
electrical supply to the boiler. Instead tu rn off th e
gas supply at a location external to the boiler.

!

WARNING

DANGER

Do not use this boiler if any part has been under
water. Immediately call your Cleaver-Brooks ser­vice representative to inspect the boiler and to re­place any part of the control system and any gas
control which has been under water.

Notice

This manual must be maintained in legible condi­tion and kept adjacent to the boiler or in a safe
place for future reference. Contact your local
Cleaver-Brooks representative if additional manu­als are required.

Notice

Where required by the authority having jurisdic­tion, the installation must conform to the Standard
for Controls and Safety Devices for Automatically
Fired Boilers, ANSI/ASME CSD-1.

!

WARNING

DANGER

The boiler and its individual shutoff valve must be
disconnected from the gas supply piping system
during any pressure testing of that system at test
pressures in excess of 1/2 psi (3.5 kPa).

!

WARNING

DANGER

The installation must conform to the requirements
of the authority having jurisdiction or, in the ab­sence of such requirements, to UL 795 Commer­cial-Industrial Gas Heating Equipment and/or the
National Fuel Gas Code, ANSI Z223.1

ii

CLEAVER-BROOKS

Model CBLE

250-350 HP

Light Oil, Heavy Oil, Gas, or Combination

Operation and Maintenance Manual

 Cleaver-Brooks 2009

Please direct purchase orders for replacement manuals to your local Cleaver-Brooks authorized representative

Manual Part No. 750-91

12/09

iii

Printed in U.S.A.

!

WARNING

DANGER

DO NOT OPERATE, SERVICE, OR REPAIR THIS EQUIPMENT UNLESS YOU FULLY UNDERSTAND ALL
APPLICABLE SECTIONS OF THIS MANUAL.

DO NOT ALLOW OTHERS TO OPERA TE, SERVICE, OR REP AIR THIS EQUIPMENT UNLESS THEY FULL Y
UNDERSTAND ALL APPLICABLE SECTIONS OF THIS MANUAL.

FAILURE TO FOLLOW ALL APPLICABLE WARNINGS AND INSTRUCTIONS MAY RESULT IN SEVERE
PERSONAL INJURY OR DEATH.

TO: Owners, Operators and/or Maintenance Personnel

This operating manual presents information that will help to properly operate and care for the equipment. Study its con­tents carefully. The unit will provide good service and continued operation if proper operating and maintenance instruc­tions are followed. No attempt should be made to operate the unit until the principles of operation and all of the
components are thoroughly understood. Failure to follow all applicable instructions and warnings may result in severe
personal injury or death.

It is the responsibility of the owner to train and advise not only his or her personnel, but the contractors' personnel who
are servicing, repairing or operating the equipment, in all safety aspects.

Cleaver-Brooks equipment is designed and engineered to give long life and excellent service on the job. The electrical
and mechanical devices supplied as part of the unit were chosen because of their known ability to perform; however,
proper operating techniques and maintenance procedures must be followed at all times. Although these components af­ford a high degree of protection and safety, operation of equipment is not to be considered free from all dangers and
hazards inherent in handling and firing of fuel.

Any "automatic" features included in the design do not relieve the attendant of any responsibility. Such features merely
free him of certain repetitive chores and give him more time to devote to the proper upkeep of equipment.

It is solely the operator’s responsibility to properly operate and maintain the equipment. No amount of written instructions
can replace intelligent thinking and reasoning and this manual is not intended to relieve the operating personnel of the
responsibility for proper operation. On the other hand, a thorough understanding of this manual is required before at­tempting to operate, maintain, service, or repair this equipment.

Because of state, local, or other applicable codes, there are a variety of electric controls and safety devices which vary
considerably from one boiler to another. This manual contains information designed to show how a basic burner operates.

Operating controls will normally function for long periods of time and we have found that some operators become lax in
their daily or monthly testing, assuming that normal operation will continue indefinitely. Malfunctions of controls lead to
uneconomical operation and damage and, in most cases, these conditions can be traced directly to carelessness and
deficiencies in testing and maintenance.

It is recommended that a boiler room log or record be maintained. Recording of daily, weekly, monthly and yearly main­tenance activities and recording of any unusual operation will serve as a valuable guide to any necessary investigation.
Most instances of major boiler damage are the result of operation with low water. We cannot emphasize too strongly the
need for the operator to periodically check his low water controls and to follow good maintenance and testing practices.
Cross-connecting piping to low water devices must be internally inspected periodically to guard against any stoppages
which could obstruct the free flow of water to the low water devices. Float bowls of these controls must be inspected
frequently to check for the presence of foreign substances that would impede float ball movement.

The waterside condition of the pressure vessel is of extreme importance. Waterside surfaces should be inspected fre­quently to check for the presence of any mud, sludge, scale or corrosion.

It is essential to obtain the services of a qualified water treating company or a water consultant to recommend the proper
boiler water treating practices.

The operation of this equipment by the owner and his or her operating personnel must comply with all requirements or
regulations of his insurance company and/or other authority having jurisdiction. In the event of any conflict or inconsis­tency between such requirements and the warnings or instructions contained herein, please contact Cleaver-Brooks be­fore proceeding.

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Model CB-LE Packaged Boiler 250-350 HP

750-91
Table of Contents

CHAPTER 1 Basics of Firetube Operation 1-1

1.1 — Introduction 1-1

1.2 — The Boiler 1-3

1.3 — Construction 1-4

1.4 — Steam Controls (All Fuels) 1-5

1.4.1 — Operating Limit Pressure Control 1-5

1.4.2 — High Limit Pressure Control 1-5

1.4.3 — Modulating Pressure Control 1-6

1.4.4 — Low Water Cutoff and Pump Control 1-6

1.4.5 — Water Column Assembly 1-7

1.4.6 — Water Column Drain Valve 1-7

1.4.7 — Water Gauge Glass Drain Valve 1-7

1.4.8 — Vent Valve 1-7

1.4.9 — Stack Temperature gauge 1-7

1.4.10 — Auxiliary Low-Water Cutoff 1-8

1.4.11 — Safety Valve(s) 1-8

1.5 — Hot Water Controls (All Fuels) 1-9

1.5.1 — Water Pressure and Temperature Gauge 1-9

1.5.2 — Operating Limit Temperature Control 1-9

1.5.3 — High Limit Temperature Control 1-9

1.5.4 — Modulating Temperature Control 1-9

1.5.5 — Low-Water Cutoff 1-9

1.5.6 — Auxiliary Low-Water Cutoff (optional) 1-10

1.5.7 — Safety Valve(s) 1-10

1.6 — IFGR Components 1-10

1.6.1 — Flue Gas Transfer Port, IFGR Damper, & Flange Collar 1-10

1.6.2 — IFGR Damper Linkage 1-10

1.6.3 — Over-Travel Mechanism 1-11

1.6.4 — Fuel Change-Over Linkage 1-11

1.6.5 — Fan/Motor Cassette 1-12

1.6.6 — Burner Drawer 1-12

1.6.7 — Combustion Air Inlet 1-12

1.6.8 — Front Door Insulation 1-12

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CHAPTER 2 Burner Operation and Control 2-1

2.1 — The Burner 2-1

2.2 — Control and Component Function 2-3

2.3 — Components Common to All Boilers 2-3

2.4 — Controls for Gas Firing 2-5

2.5 — Controls Common to Oil-Fired Boilers 2-9

2.6 — Additional Controls for Heavy Oil 2-13

2.7 — Controls for Combination Burners Only 2-15

2.8 — Combustion Air 2-16

2.9 — Automatic Ignition 2-16

CHAPTER 3

2.10 — Atomizing Air 2-17

2.11 — Oil Fuel Flow: Light Oil 2-17

2.12 — Oil Fuel Flow: Heavy Oil 2-19

2.13 — Gas Fuel Flow 2-21

2.14 — Modulating Firing 2-21

Waterside Care and Requirements 3-1

3.1 — Overview 3-1

3.2 — Water Requirements: Hot Water Boiler 3-1

3.2.1 — Air Removal 3-1

3.2.1.1 — Minimum Water Temperature 3-2

3.2.1.2 — Rapid Replacement of Boiler Water 3-2

3.2.1.3 — Continuous Flow Through the Boiler 3-2

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3.2.2 — Water Circulation 3-2

3.2.2.1 — Multiple Boiler Installations 3-3

3.2.2.2 — Pump Location 3-4

3.2.2.3 — Pump Operation 3-4

3.2.3 — Pressure 3-4

3.3 — Water Requirements: Steam Boiler 3-5

3.3.1 — Feed Pump Operation 3-5

3.3.2 — Water Feeder (optional) Operation 3-6

3.4 — Water Treatment 3-6

3.5 — Cleaning 3-7

3.5.1 — Hot Water and Steam Piping 3-7

3.5.2 — Pressure Vessel 3-7

3.6 — Boil-Out of a New Unit 3-8

3.7 — Washing Out 3-10

3.7.1 — Hot Water Boiler 3-10

3.7.2 — Steam Boiler 3-10

3.7.3 — Flushing of Pressure Vessel Interior 3-10

CHAPTER 4

3.8 — Blowdown: Steam Boiler 3-10

3.8.1 — Intermittent Manual Blowdown 3-11

3.8.2 — Continuous Blowdown 3-11

3.8.3 — Frequency of Manual Blowdown 3-11

3.8.4 — Manual Blowdown Procedure 3-12

3.9 — Periodic Inspection 3-13

3.10 — Preparation for Extended Lay-Up 3-14

Sequence of Operation 4-1

4.1 — Overview 4-1

4.2 — Circuit and Interlock Controls 4-2

4.3 — Sequence of Operation: Oil or Gas 4-3

4.3.1 — Pre-Purge Cycle 4-3

4.3.2 — Ignition Cycle 4-4

4.3.3 — Run Cycle 4-4

4.3.4 — Burner Shutdown: Post Purge 4-5

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4.4 — Flame Loss Sequence 4-5

4.4.1 — No Pilot Flame 4-6

4.4.2 — Pilot But No Main Flame 4-6

4.4.3 — Loss of Flame 4-6

CHAPTER 5 Starting and Operating Instructions 5-1

5.1 — Preparation for Startup: All Fuels 5-1

5.2 — Control Settings: Steam and Hot Water 5-2

5.2.1 — Operating Limit Control 5-2

5.2.2 — High Limit Control 5-2

5.2.3 — Modulating Control 5-3

5.2.4 — Low-Water Cutoff and Pump Control 5-3

5.2.5 — Additional Considerations 5-3

5.3 — Gas Pilot 5-3

5.4 — Atomizing Air 5-4

5.5 — Firing Preparations for No. 2 Oil (Series 100 - 200) 5-5

5.5.1 — Oil Flow 5-5

5.5.2 — Oil Pressure 5-6

5.5.3 — Starting 5-7

5.6 — Firing Preparation for No. 6 Oil (Series 400 - 600) 5-7

5.6.1 — Oil Flow 5-7

5.6.2 — Oil Pressure 5-8

5.6.3 — Oil Temperature 5-8

5.6.4 — Starting 5-9

5.7 — Firing Preparations for Gas (Series 200-400-700) 5-9

5.8 — IFGR Setup 5-11

5.9 — Startup, Operating and Shutdown: All Fuels 5-13

5.9.1 — Operating 5-14

5.9.2 — Shutdown 5-15

5.10 — Control Operational Test and Checks 5-15

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CHAPTER 6 Adjustment Procedures 6-1

6.1 — Overview 6-1

6.1.1 — High Turndown Burner 6-1

6.2 — Linkage: Modulating Motor and Air Damper 6-2

6.3 — Modulating Motor 6-4

6.4 — Modulating Motor Switches: Low-Fire and High-Fire 6-4

6.5 — Burner Operating Controls: General 6-5

6.6 — Modulating Pressure Control: Steam 6-8

6.7 — Operating Limit Pressure Control: Steam 6-8

6.8 — High Limit Pressure Control: Steam 6-8

6.9 — Modulating Temperature Control: Hot Water 6-8

6.10 — Operating Limit Temperature Control: Hot Water 6-9

6.11 — High Limit Te m perature Control: Hot Water 6-9

6.12 — Low Water Cutoff Devices: Steam & Hot Water 6-10

6.13 — Combustion Air Proving Switch 6-10

6.14 — Atomizing Air Proving Switch 6-10

6.15 — Gas Pilot Flame Adjustment 6-11

6.15.1 — Measure and Adjust Pilot 6-11

6.16 — Gas Pressure and Flow Information 6-12

6.16.1 — Pressure 6-12

6.16.2 — Gas Flow 6-15

6.16.3 — Pressure Correction 6-15

6.16.4 — Checking Gas Flow 6-16

6.17 — Gas Fuel Combustion Adjustment 6-17

6.17.1 — Standard Burner Low-Fire Adjustment 6-20

6.17.2 — High Turndown Burner Low-Fire Adjustment 6-21

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6.18 — Low-Gas Pressure Switch 6-21

6.19 — High-Gas Pressure Switch 6-21

6.20 — Fuel Oil Pressure and T emperature: General 6-22

6.21 — Fuel Oil Combustion Adjustment 6-23

6.21.1 — Standard Burner Low-Fire Adjustment: Heavy Oil 6-25

6.21.2 — High Turndown Burner Low-Fire Adjustment: Light Oil 6-25

6.22 — Burner Drawer Adjustment 6-25

6.23 — Oil Drawer Switch 6-26

6.24 — Low Oil Temperature Switch 6-27

6.25 — High Oil Temperature Switch (Optional) 6-27

6.26 — Low Oil Pressure Switch (Optional) 6-27

CHAPTER 7

CHAPTER 8

6.27 — Electric Oil Heater Thermostat (400 and 600 Series: Steam) 6-27

6.28 — Steam Oil Heater Thermostat: No. 6 Oil (400 and 600 Series: Steam) 6-28

6.29 — Hot Water Oil Heater Thermostat (400 and 600 Series) 6-28

6.30 — Steam Heater Pressure Regulator (400 and 600 Series: Steam) 6-28

Troubleshooting 7-1

7.1 — Overview 7-1

Inspection and Maintenance 8-1

8.1 — Overview 8-1

8.1.1 — Periodic Inspection 8-2

8.2 — Fireside Cleaning 8-2

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750-91 (revised 2009)

8.3 — Water Level Controls 8-3

8.3.1 — Steam Boiler 8-3

8.3.2 — Hot Water Boiler 8-4

8.4 — Water Gauge Glass 8-4

8.5 — Electrical Controls 8-4

8.6 — Flame Safety Control 8-6

8.6.1 — Checking Pilot Flame Failure 8-6

8.6.2 — Checking Failure to Light Main Flame 8-7

8.6.3 — Checking Loss of Flame 8-7

8.7 — Oil Burner Maintenance 8-7

8.7.1 — Oil Strainers 8-7

8.7.2 — Light Oil Strainers 8-7

8.7.3 — Heavy Oil Strainers 8-8

8.7.4 — Cleaning the Oil Nozzle 8-8

8.7.5 — Cleaning Air Purge Nozzle (No. 6 Oil) and Back Pressure Orifice Nozzle (No. 2 Oil) 8-9

8.7.6 — Ignition System 8-9

8.8 — Gas Burner Maintenance 8-9

8.9 — Motorized Gas Valve 8-10

8.10 — Solenoid Valves 8-10

8.11 — Air Control Damper, Linkage, and Cam Spring 8-11

8.12 — Forced Draft Fan 8-12

8.13 — Fan/Motor Cassette Removal 8-14

8.14 — Inspection and Adjustment 8-15

8.15 — Airbox Gasket Installation 8-16

8.16 — Fan/Motor Cassette Installation 8-17

8.17 — Safety Valves 8-18

8.18 — Fuel Oil Metering Valve, Adjusting, and Relief Valves 8-18

8.19 — Air Pump and Lubricating System 8-20

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8.19.1 — Air Compressor 8-20

8.19.2 — Lubricating Oil 8-20

8.19.3 — Lubricating Oil Strainer and Cooling Coil 8-21

8.19.4 — Air Cleaner 8-21

8.19.5 — Air-Oil Tank 8-21

8.19.6 — Lube Oil Cooling Coil 8-22

8.19.7 — Flexible Coupling Alignment 8-22

8.19.8 — Air Compressor Replacement 8-24

8.19.8.1 — Dismantling 8-24

8.19.8.2 — Reassembly 8-24

8.20 — Refractory 8-25

8.20.1 — Furnace Liner 8-26

8.20.2 — Throat Tile and Liner Installation 8-27

8.20.3 — Installation 8-28

8.21 — Head Inspection and Maintenance 8-29

8.21.1 — Front Head 8-30

8.21.2 — Rear Door 8-31

8.21.3 — Closing and Sealing 8-33

8.22 — Lubrication 8-34

8.22.1 — Electric Motors 8-34

8.22.2 — Control Linkage 8-34

8.22.3 — Solenoid and Motorized Valves 8-34

8.22.4 — IFGR Lubrication 8-35

CHAPTER 9

8.23 — Oil Heater: Electric, Steam, Hot Water 8-35

8.24 — Combustion 8-36

8.26 — Recommended Boiler Inspection Schedule 8-37

Parts 9-1

9.1 — Ordering Parts 9-1

9.2 — Parts Lists and Drawings 9-2

9.2.1 — Air Compressor and Piping 9-2

9.2.2 — Side Mounted Air Compressor Piping 9-3

9.2.3 — Air Line Piping 9-4

9.2.4 — Burner Housing Support & Front Head Plt 9-5
Burner Housing Support & Front Head Plt 9-6

9.2.5 — Control Panel 9-7

9.2.6 — Entrance Box 9-9

9.2.7 — Front Head (Electrical) 9-10

9.2.8 — Front Davit 9-11

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9.2.9 — Front Head Insulation 9-12

9.2.10 — Front Head Linkage 9-13

9.2.11 — Gas Train 9-14

9.2.12 — Light Oil/Air Piping 9-16

9.2.13 — Heavy Oil/Air Piping 9-18

9.2.14 — Heavy OIl Alstrom Heater 9-20

9.2.15 — CB-LE IFGR 9-22

9.2.16 — IFGR Impeller 9-24

9.2.17 — Pressure Controls 9-25

9.2.18 — Temperature Controls 9-26

9.2.19 — W.C. - Main & Aux. 9-27

9.2.20 — Vessel Handholes & Manways 9-29

9.2.21 — Rear Head Sealing - Davit 9-30

9.2.22 — Throat Tile and Furnace Liner 9-31

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CHAPTER 1 Basics of Fir etube Operation

1.1 — Introduction

Firetube boilers are available for low or high pressure steam, or for hot water applications. Firetube boilers are typ­ically used for applications ranging from 15 to 800 horsepower. A firetube boiler is a cylindrical vessel, with hori­zontal tubes passing through and connected to the front and rear tube sheets. The vessel contains the water and
absorbs the energy generated from the flame. The front door and rear door provide the seal to contain the hot
combustion gasses. Baffles designed into the doors serve to redirect the combustion gasses through the various
firetube passages. The flame originates in the furnace. As the combustion gasses travel down the furnace and
through the various firetube channels, heat from the flame and combustion gasses is transferred to the water.
Transferred energy develops into the required steam or hot water. The primary purpose of the boiler is to supply
energy to the facility’s operations — for heat, manufacturing processes, laundry, kitchen, etc. The nature of the
facility’s operation will dictate whether a steam or hot water boiler should be used.

The general information in this manual applies directly to Cleaver-Brooks Model CBLE Boilers in sizes ranging
from 250 through 350 boiler horsepower for the following fuels:

• Series 100 Light Oil (No. 2) only

• Series 200 Light Oil (No. 2) or Gas

• Series 400 Heavy Oil (No. 6) or Gas

• Series 600 Heavy Oil (No. 6) only

• Series 700 Gas only

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Basics of Firetube Operation

FIGURE 1-1. Firetube Boiler (cutaway view)

Rated Capacity 250 through 350 hp

Operating Pressure Steam: 15 - 250 psig, or higher if specified

Hot Water: 30 - 250 psig, or higher if specified

Fuel Oil or Gas or Combination

Ignition Automatic

Firing Full Modulation Through Operating Ranges

Burner (Oil) (Low Pressure) Air Atomizing

Burner (Gas) Non-premix, Orificed Type

Air Damper Rotary Type (Electrically Modulated)

Steam Trim ASME Code

Water Trim ASME Code

The LE (Low Emission) feature reduces nitrogen oxide (NOX) emissions, a major precursor to ozone pollution
(smog). Carbon monoxide (CO) emissions also tend to be lower, die to increased turbulence caused by the addition
of the flue gasses into the combustion air stream, thereby improving combustion.

The LE Option is used on Cleaver-Brooks Model CB firetube boilers firing either natural gas and/or light oil, and
is compatible with both hot water and steam systems.

1-2

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1.2 — The Boiler

The IFGR system mixes a portion of the relatively cool flue gas from the exit of the fourth-pass tubes with the
incoming combustion air to reduce the furnace flame temperature, thereby reducing NO

emissions. In this

X

approach, the combustion air fan handles both the combustion air and the recirculated flue gasses. Accordingly,
this method is called Induced Flue Gas Recirculation (IFGR) because the flue gas is “induced” into the fan inlet.

The LE Option, with its various levels of IFGR systems, can affect the selection of the combustion air fan, motor,
burner, and other components. Several different system configurations are available, depending on the require­ments for NO

emissions and the fuels used. All systems use similar primary components, but may have different

X

linkage controls, IFGR damper, fan, and motor sizes.

When firing heavy oil in a gas/oil CBLE boiler, the heavy oil isolation valve is required in order to protect the
IFGR system from soot buildup and corrosion. See CB manual 750-171 for operating details on the Heavy Oil Iso­lation system.

Always order genuine Cleaver-Brooks parts from your local Cleaver-Brooks authorized representative.

The boiler and related equipment installation are to be in compliance with the standards of the National Board of
Fire Underwriters. Installation should also conform to state and local codes governing such equipment. Prior to
installation, the proper authorities having jurisdiction are to be consulted, permits obtained, etc. All boilers in the
above series comply, when equipped with optional equipment, to Industrial Risk Insurers (IRI), Factory Mutual
(FM), or other insuring underwriters requirements.

1.2 — The Boiler

The Model CBLE boiler is a packaged firetube boiler of welded steel construction and consists of a pressure vessel,
burner, burner controls, forced draft fan, damper, air pump, refractory, and appropriate boiler trim.

The horsepower rating of the boiler is indicated by the numbers following the fuel series. Thus, CB700-250 identi­fies a gas-fired 250 hp boiler.

The firetube construction provides some characteristics that differentiate it from other boiler types. Because of its
vessel size, the firetube contains a large amount of water, allowing it to respond to load changes with minimum
variation in steam pressure.

Firetube boilers are rated in boiler horsepower (BHP), which should not be confused with other horsepower mea­surements.

Hot water is commonly used in heating applications with the boiler supplying water to the system at 180º F to 220º
F. The operating pressure for hot water heating systems usually in 30 psig to 125 psig.

Steam boilers are designed for low pressure or high pressure applications. Low pressure boilers are limited to 15
psig design, and are typically used for heating applications. High pressure boilers are typically used for process loads
and can have a design pressure of 75 to 350 psig.

Steam and hot water boilers are defined according to design pressure and operating pressure. Design pressure is the
maximum pressure used in the design of the boiler for the purpose of calculating the minimum permissible thick-

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1-3

Basics of Firetube Operation

ness or physical characteristics of the pressure vessel parts of the boiler. Typically, the safety valves are set at or
below design pressure. Operating pressure is the pressure of the boiler at which it normally operates. The operating
pressure usually is maintained at a suitable level below the setting of the pressure relieving valve(s) to prevent their
frequent opening during normal operation.

The type of service that your boiler is required to provide has an important bearing on the amount of waterside
care it will require.

Caution

!

Waterside care is of prime importance. For specific information or assistance with your water treatment requirements,
contact your Cleaver-Brooks service and parts representative. Failure to follow these instructions could result in equip­ment damage.

Feedwater equipment should be checked and ready for use. Be sure that all valves, piping, boiler feed pumps, and
receivers are installed in accordance with prevailing codes and practices.

Water requirements for both steam and hot water boilers are essential to boiler life and length of service. Constant
attention to water requirements will pay dividends in the form of longer life, less downtime, and prevention of
costly repairs. Care taken in placing the pressure vessel into initial service is vital. The waterside of new boilers and
new or remodeled steam or hot water systems may contain oil, grease, or other foreign matter. A method of boiling
out the vessel to remove accumulations is described in Chapter 3.

The operator should be familiar with Chapter 3 before attempting to place the unit into operation.

1.3 — Construction

Steam boilers designed for 15 psig and hot water boilers designed for 250º F at 125 psi or less are constructed in
accordance with Section IV, Power Boilers, of ASME Code.

Steam boilers designed for operating pressures exceeding 15 psig are constructed in accordance with Section 1,
Power Boilers, of the ASME Code. Hot water boilers designed for operating temperatures above 250º F or 125 psi
are likewise built to ASME Code Section 1.

1-4

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1.4 — Steam Controls (All Fuels)

FIGURE 1-2. Steam Boiler: Light Oil or Gas Fired

1.4 — Steam Controls (All Fuels)

1.4.1 — Operating Limit Pressure Control

Breaks a circuit to stop burner operation on a rise of boiler pressure at a selected setting. It is adjusted to stop or
start the burner at a preselected pressure setting.

1.4.2 — High Limit Pressure Control

Breaks a circuit to stop burner operation on a rise of pressure above a selected setting. It is adjusted to stop the
burner at a preselected pressure above the operating limit control setting. The high limit pressure control is nor­mally equipped with a manual reset.

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Basics of Firetube Operation

1.4.3 — Modulating Pressure Control

Senses changing boiler pressures and transmits the information to the modulating motor to change the burner fir­ing rate when the manual-automatic switch is set on “automatic.”

FIGURE 1-3. Boiler Controls

1.4.4 — Low Water Cutoff and Pump Control

Float-operated control responds to the water level in the boiler. It performs two distinct functions:

• Stops firing of the burner if water level lowers below the safe operating point. Energizes the low-water light in

the control panel, and it also causes the low-water alarm bell (optional equipment) to ring. Code requirements of
some models require a manual reset type of low-water cutoff.

• Starts and stops the feedwater pump (if used) to maintain water at the proper operating level.

The CB Level Master is the standard low water cutoff on high pressure steam boilers. See CB manual 750-281 for
complete operation, maintenance, and parts information.

Caution

!

Determine that the main and auxiliary low water cutoffs and pump control are level after installation and throughout
the equipment’s operating life. Failure to follow these instructions could result in equipment damage.

1.4.5 — Water Column Assembly

Houses the low-water cutoff and pump control and includes the water gauge glass and gauge glass shutoff cock.

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1.4 — Steam Controls (All Fuels)

1.4.6 — Water Column Drain Valve

Provided so that the water column and its piping can be flushed regularly to assist in maintaining cross-connecting
piping and in keeping the float bowl clean and free of sediment. A similar drain valve is furnished with auxiliary
low-water cutoff for the same purpose.

1.4.7 — Water Gauge Glass Drain Valve

Provided to flush the gauge glass.

CB LEVEL MASTER

(HIGH PRESSURE STEAM)

FIGURE 1-4. Water Column Assembly & LWCO

LOW PRESSURE STEAM

1.4.8 — Vent Valve

Allows the boiler to be vented during filling, and facilitates routine boiler inspection as required by ASME Code.

1.4.9 — Stack Temperature gauge

Indicates flue gas outlet temperature.

1.4.10 — Auxiliary Low-Water Cutoff

Breaks the circuit to stop burner operation in the event boiler water drops below the master low-water cutoff point.
Manual reset type requires manual resetting in order to start the burner after a low-water condition.

1.4.11 — Safety Valve(s)

Prevents buildup over the design pressure of the pressure vessel. The size, rating, and number of valves on a boiler
is determined by the ASME Boiler Code. The safety valve and the discharge piping are to be installed to conform
to the ASME Code requirements. The installation of a valve is of primary importance to its service life. A valve
must be mounted in a vertical position so that discharge piping and code required drains can be properly piped to

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Basics of Firetube Operation

prevent buildup of back pressure and accumulation of foreign material around the valve seat area. Apply only a
moderate amount of pipe compound to male threads and avoid overtightening, which can distort the seats. Use
only flat-jawed wrenches on the flats provided. When installing a flange-connected valve, use a new gasket and
draw the mounting bolts down evenly. Do not install or remove side outlet valves by using a pipe or wrench in the
outlet.

FIGURE 1-5. Safety Valve

Warning

!

Only properly qualified personnel such as the safety valve manufacturer’s certified representative can adjust or repair
the boiler safety valves. Failure to follow these instructions could result in serious injury or death.

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1.5 — Hot Water Controls (All Fuels)

1.5 — Hot Water Controls (All Fuels)

1.5.1 — Water Pressure and Temperature Gauge

Indicates the internal water pressure and the boiler water temperature.

FIGURE 1-6. Water Pressure and Temperature Gauge & Limit Controls (configurations will vary)

1.5.2 — Operating Limit Temperature Control

Breaks a circuit to stop burner operation on a rise of boiler temperature at a selected setting. It is adjusted to stop
or start the burner at a preselected operating temperature.

1.5.3 — High Limit Temperature Control

Breaks a circuit to stop burner operation on a rise of temperature at a selected setting. It is adjusted to stop burner
at a preselected temperature above the operating control setting. The high limit temperature control normally is
equipped with a manual reset.

1.5.4 — Modulating Temperature Control

Senses changing boiler water temperature and transmits the information to the modulating motor to change the
burner firing rate when the manual-automatic switch is set on “automatic.”

1.5.5 — Low-Water Cutoff

Breaks the circuit to stop burner operation if the water level in the boiler drops below a safe operating point, acti­vating a low-water light and optional alarm bell if burner is so equipped.

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Basics of Firetube Operation

1.5.6 — Auxiliary Low-Water Cutoff (optional)

Breaks the circuit to stop burner operation if the water level in the boiler drops below the master low-water cutoff
point.

1.5.7 — Safety Valve(s)

Relieves the boiler of pressure higher than the design pressure or a lower pressure, if designated. Relief valves and
their discharge piping are to be installed to conform to ASME Code requirements.

Warning

!

Only properly qualified personnel such as the safety valve manufacturer’s certified representative can adjust or repair
the boiler safety valves. Failure to follow these instructions could result in serious injury or death.

1.6 — IFGR Components

1.6.1 — Flue Gas Transfer Port, IFGR Damper, & Flange Collar

The flue gas transfer port is a tube that allows the flue gasses to travel from the exit of the fourth-pass tubes to the
entrance of the combustion air fan.

The IFGR damper controls the volume of flue gas induced into the combustion air stream. The damper is located
in the flue gas transfer port and is positioned by the control linkage.

1.6.2 — IFGR Damper Linkage

The IFGR damper is positioned by the control linkage. The linkage could consist of a single arm, or it could con­sist of several arms driven from the jackshaft to provide modulating control.

FIGURE 1-7. Induced Flue Gas Recirculation System

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1.6 — IFGR Components

1.6.3 — Over-Travel Mechanism

The over-travel mechanism has two functions. It allows the linkage to pass through the front door, and it allows
jackshaft rotation to exceed (over-travel) IFGR linkage movement. A set of springs allows the linkage to stay in a
fixed position while the jackshaft rotates.

1.6.4 — Fuel Change-Over Linkage

When a boiler is equipped to fire either gas or oil (dual fuel boilers), and the required NO

levels are below 60 ppm

X

on natural gas, a dual linkage arrangement is used to provide the different recirculation rates required for each fuel.
Two jackshaft drive arms are provided, one for oil and one for gas. The linkage is manually connected to the appro­priate arm, based on the fuel being used.

On dual fuel boilers with two jackshaft drive arms, as defined above, a proximity switch is used to prove that the
correct linkage connection is made. (Refer to the wiring diagram provided with the boiler.)

FIGURE 1-8. Damper Linkage

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Basics of Firetube Operation

1.6.5 — Fan/Motor Cassette

The fan and motor assemblies are designed as a cassette so that they can be removed from the front of the boiler
without opening the front door. The front door davit arm can be used to remove the assembly.

FIGURE 1-9. Fan/Motor Cassette

1.6.6 — Burner Drawer

The spudding pattern for the IFGR system may be different than that of a non-IFGR, High-Turndown CB Burner
of the same horsepower (HP) model designation.

1.6.7 — Combustion Air Inlet

The combustion air inlets are located at the top of the front door. Air enters from the rear of the air inlet shrouds,
which reduces the sound level and captures heat from the boiler and stack flue outlet.

1.6.8 — Front Door Insulation

If NO

emissions are below 60 ppm, the front door is insulated inside to control temperature build up. The insula-

X

tion is held in place with wire mesh.

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CHAPTER 2 Burner Operation and

Contr ol

2.1 — The Burner

The oil burner is of the low pressure, air atomizing (nozzle) type. The gas burner is of the non-premix orifice type.
The burners are ignited by a spark ignited gas pilot. The pilot is of the interrupted type and is extinguished after
main flame is established.

Burners equipped to burn oil and gas (combination burners) include equipment for each distinct fuel. Since the
burner uses only one type of fuel at a time, a gas/oil selector switch is incorporated.

Regardless of which fuel is used, the burner operates with full modulation (within its rated operating range). The
burner returns to minimum firing position for ignition. High-pressure boilers (above 15 psi) can be wired for both
low-pressure and high-pressure modulation, which enables the boiler to operate at lower pressure during off-load
hours, but at a somewhat reduced steam output, dependent upon lower steam pressure and steam nozzle sizing.

The flame safeguard and program relay include a flame detector to supervise both oil and gas flames, and to shut
the burner down in the event of loss of flame. The programming portion of the control provides a pre-purging
period, proving of the pilot and main flame, and a period of continued blower operation to post-purge the boiler of
all unburned fuel vapor. Other safety controls shut down the burner under low-water conditions, excess steam
pressure, or water temperature.

Safety interlock controls include combustion and atomizing air proving switches and, depending upon the fuel and
insurance carrier requirements, controls that prove the presence of adequate fuel pressure, plus temperature prov­ing controls when heated fuel oil is used.

The sequence of burner operation from startup through shutdown is governed by the program relay in conjunction
with the operating, limit, and interlock devices. The devices are wired into the circuitry to provide safe operation
and protect against incorrect operating techniques.

All CBLE boilers have the burner assembly attached to the front head. The entire head may be swung open for
inspection and maintenance.

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Burner Operation and Control

Combustion air is provided by a centrifugal blower located in the front head. Combustion air delivery to the burner
is under the control of the modulating motor. The motor also regulates the flow of fuel through a linkage system
connected to the gas butterfly valve and/or oil through a cam operated metering valve. Fuel input and air are thus
properly proportioned for most efficient combustion.

Filtered primary air for atomizing fuel oil is furnished independently of combustion air by a frame mounted air
pump.

The burner control circuit operates on 115 volt, single phase 60 Hz (or 50 Hz if so equipped) alternating current.
The forced draft fan motor is generally operated on 3-phase service at the available main power supply voltage.

Indicator lights signaling load demand, fuel valve, low water, and flame failure conditions are standard equipment.

In addition to the standard basic controls supplied, other devices may be required to meet specific requirements of
an insurance carrier or local code. Refer to the wiring diagram (WD) prepared by Cleaver-Brooks for your specific
installation to determine the specific controls in the burner and limit control circuits. The function of individual
components is outlined in this chapter and the electrical sequence is covered in Chapter 3.

2.2 — Control and Component Function

The term “control” covers the more important valves and components, including, but not limited to, electrical con­trols or those monitored by the program relay. The operator must become familiar with the individual functioning
of all controls before understanding boiler operation and procedures outlined in this manual.

The actual controls furnished with any given boiler will depend upon the type of fuel for which it is equipped, and
whether it is a hot water or steam boiler. Refer to the applicable group or groups within this chapter that apply to
the particular boiler.

NOTE: Boilers with optional features may have control components not listed here.

2.3 — Components Common to All Boilers

Component Description

Forced Draft Fan Motor Drives forced draft fan directly to provide combustion air. Also

referred to as a blower motor.

Forced Draft Fan Provides all air, under pressure, for combustion of pilot fuel and

main fuel, and for purging.

Modulating Motor Operates the rotary air damper and fuel metering valves through a

cam and linkage system to provide proper air/fuel ratios under all
boiler load conditions.

Modulating Motor Transformer (located in the
modulating motor)

Reduces control circuit voltage (115 Vac) to required voltage (24
Vac) for operation of the modulating motor.

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2.3 — Components Common to All Boilers

Component Description

Forced Draft Fan Motor Starter Energizes forced draft fan (blower) motor.

Ignition Transformer Provides high voltage spark for ignition of gas pilot or light oil pilot.

Low Fire Switch An internal auxiliary switch, cam actuated by the motor shaft, which

must be closed to indicate that the air damper and fuel metering
valve are in the low fire position before an ignition cycle can occur.

Atomizing Air Proving Switch A pressure sensitive switch actuated by air pressure from the air

pump. Its contacts close to prove presence of atomizing air. The
fuel valves cannot be energized unless this switch is satisfied.

Manual-Automatic Switch When set at “automatic,” subsequent operation is at the command

of the modulating control, which governs the position of the modu­lating motor in accordance with load demand. When set at “man­ual,” the modulating motor, through the manual flame control, can
be positioned at a desired burner firing rate. The primary purpose
of the manual position is for testing and setting the air/fuel ratio
through the entire firing range.

Manual Flame Control A manually operated potentiometer that permits the positioning of

the modulating motor to a desired burner firing rate when the man­ual-automatic switch is set on “manual.” It is used primarily for ini­tial or subsequent setting of fuel input throughout the firing range.
It has no control over the firing rate when the manual-automatic
switch is set on “automatic.”

Burner Switch A manually operated start-stop switch for directly starting and

stopping burner operation.

Flame Detector Monitors gas or oil pilot and energizes the programmer flame relay

in response to a flame signal. It continues to monitor main flame
(oil or gas) after expiration of pilot providing period. a standardly
equipped boiler has a lead sulfide (infrared sensitive) detector.

Combustion Air Proving Switch A pressure sensitive switch actuated by air pressure from the forced

draft fan. Its contacts close to prove presence of combustion air.
The fuel valves cannot be energized unless this switch is satisfied.

Alarm Sounds to notify the operator of a condition requiring attention.

The alarm is available as optional equipment.

Stack Thermometer Indicates temperature of vented flue gasses.

Diffuser A circular plate, located at the furnace end of the burner drawer,

that imparts a rotary swirling motion to combustion air immediately
prior to its entering the flame, thus providing a thorough and effi­cient mixture with the fuel.

Rotary Air Damper Provides accurate control of combustion air in proportion to fuel

input for various load demands. It consists of two concentric cylin­ders with openings. The outer is stationary. The inner is rotated,
under control of the modulating motor, to vary the effective size of
the openings where they overlap.

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Burner Operation and Control

Component Description

Indicator Lights Provide visual information of boiler operation as follows:

• Flame Failure

• Load Demand

• Fuel Valve (valve open)

• Low Water

Program Relay and Flame Safeguard Control Automatically programs each starting, operating, and shutdown

period in conjunction with operating limit and interlock devices.
Includes, in a timed an proper sequence, the operation of the blower
motor, ignition system, fuel valve(s), and the damper motor. The
sequence includes air purge periods prior to ignition and upon
burner shutdown.

The flame detector portion of the control monitors both oil and gas
flames and provides protection in the event of loss of a flame signal.

The control recycles automatically during normal operation, or fol­lowing a power interruption. It must be manually reset following a
safety shutdown caused by a loss of flame. An internal checking cir­cuit, effective on every start, prevents burner operation in the event
anything causes the flame relay to hold in during this period.

2.4 — Controls for Gas Firing

Depending upon the requirements of the insurance carrier or other governing agencies, the gas flow control sys­tem, or gas train, may consist of some, or all, of the items listed below.

Component Description

Gas Pilot Valve A solenoid valve that opens during the ignition period to admit fuel

to the pilot. It closes after main flame is established. The sequence
of energizing and de-energizing is controlled by the programming
relay. A second gas pilot valve may be required by insurance regula­tions.

Gas Pilot Vent Valve When a second gas pilot valve is required, a normally open vent

valve (optional equipment) is installed between them. Its purpose is
to vent gas to the atmosphere, should any be present in the pilot
line when the pilot valves are closed. The valve closes when the
pilot valves are energized.

Gas Pilot Shutoff Cock For manually opening or closing the gas supply to the gas pilot

valve.

Gas Pressure Gauge Indicates gas pressure to pilot.

Gas Pressure Regulating Valve Reduces incoming gas pressure to suit the pilot.

Gas Pilot Aspirator Provides complete mixing of gas and air to the pilot.

Gas Pilot Adjusting Cock Regulates the size of the gas pilot flame.

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2.4 — Controls for Gas Firing

Component Description

Gas Modulating Cam An assembly, consisting of a quadrant, a series of adjustable allen-

head screws, and a contour spring, provided for adjustment of gas
input at any point in the modulating range.

Main Gas Cock For manually opening and closing the main fuel gas supply down-

stream of the main gas line pressure regulator. A second shutoff
cock, downstream of the main gas valve(s), is installed to provide a
means of shutting off the gas line whenever a test is made for leak­age across the main gas valve.

Butterfly Gas Valve The pivoted disc in the valve is actuated by connecting linkage from

the gas modulating cam to regulate the rate of gas flow to the
burner.

Main Gas Valves Electrically actuated shutoff valves that open simultaneously to

admit gas to the burner. The downstream valve is equipped with a
“proof of closure” switch that is connected into the pre-ignition
interlock circuit.

Low Gas Pressure Switch A pressure actuated switch that is closed whenever main gas line

pressure is above a preselected pressure. Should the pressure drop
below the setting, the switch contacts open a circuit causing the
main gas valve(s) to close, or prevent the burner from starting. The
switch is usually equipped with a device that must be manually reset
after being tripped.

High Gas Pressure Switch A pressure actuated switch that is closed whenever main gas line

pressure is below a preselected pressure. Should the pressure rise
above the setting, the switch contacts will open a circuit causing the
main gas valve(s) to close, or prevent the burner from starting. The
switch is usually equipped with a device that must be manually reset
after being tripped.

Leakage Connection The body of the gas valve has a plugged opening that is used when-

ever it is necessary to conduct a test for possible leakage across the
closed valve.

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Burner Operation and Control

FIGURE 2-1. Gas Train (configurations may vary)

FIGURE 2-2. Gas Modulating Cam

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2.4 — Controls for Gas Firing

FIGURE 2-3. Secondary Air Flow with Gas Train

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Burner Operation and Control

2.5 — Controls Common to Oil-Fired Boilers

The following items are applicable to all oil-fired or gas and oil-fired boilers. Additional controls for No. 6 oil are
listed in section 2.6.

FIGURE 2-4. Front of Burner Drawer.

Component Description

Oil Drawer Switch Opens the limit circuit if oil drawer burner gun is not latched in the

forward position required for burning oil.

Atomizing Air Proving Switch Pressure actuated switch whose contacts are closed when sufficient

atomizing air pressure from the air pump is present for oil firing. Oil
valve(s) will not open, or will not remain open, unless switch con­tacts are closed.

Atomizing Air Pressure Gauge Indicates the atomizing air pressure at the burner gun.

Oil Solenoid Valve Opens when energized through contacts in the programmer and

allows fuel oil flow from the oil metering valve to the burner nozzle.
A light oil fired burner uses two valves operating simultaneously.

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2.5 — Controls Common to Oil-Fired Boilers

Component Description

Fuel Oil Controller An assembly combining into a single unit the gauges, regulators,

and valves required for regulating the flow of fuel oil. All controllers
have the following integral parts. In addition to these, the controller
used on a No. 6 oil fired burner has additional components
described in section 2.1.

• Oil Metering Valve: Valve metering stem moves to increase or

decrease the orifice area to regulate the supply of fuel oil to the
burner nozzle in accordance with boiler load variances. Stem
movement is controlled by the modulating motor through link­age and the oil metering cam.

• Oil Modulating Cam: Assembly consisting of a quadrant, a series

of adjustable allen-head screws and a contour spring provided
for adjustment of oil input at any point in the modulating range.

• Oil Burner Pressure Gauge: Indicates pressure of the fuel oil at

the metering valve.

• Oil Pressure Regulator: For adjustment of the pressure of oil at

the metering valve.

Oil Relief Valve Maintains a constant oil supply pressure to the fuel oil controller by

bypassing excess fuel oil.

Ter m inal Block

Fuel Oil Strainer Prevents foreign matter from entering the burner system.

Gas Pilot See section 2.4 for description of the various components.

Light Oil Pilot Valve: When a light oil pilot is furnished, a solenoid valve is provided to

control flow of fuel to the pilot nozzle. It is energized through pro­grammer contacts. It is de-energized to shut off pilot fuel flow after
main flame is ignited and established.

Back Pressure Orifice A restriction located in the oil return line immediately downstream

of the fuel oil controller to create back pressure (100 and 200 series
only).

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Burner Operation and Control

Component Description

Air Pump Module Assembly Provides the compressed air required to atomize the fuel oil for

proper combustion. It is started automatically by the programmer’s
sequence. Components include:

• Air Pump Motor: Drives the air pump and an air cooling fan.

The motor is started and stopped simultaneously with the
forced draft fan motor.

• Air Pump: Provides air for atomization of the fuel oil.

• Air Filter: The filter cleans the air supply prior to entering the air

pump.

• Check Valve: Prevents lubricating oil and compressed air from

surging back through the pump and air filter when the pump
stops.

• Air-Oil Receiver Tank: Holds a supply of oil for lubricating the

air pump. The receiver tank also separates lube oil from the
atomizing air before delivery to the nozzle.

• Lube Oil Level Sight Glass: Indicates the level of lubricating oil

in the air-oil receiver tank.

• Lube Oil Cooling Coil: Cools the lubricating oil before it enters

the air pump. A fan driven by the air pump motor circulates
cooling air over the coil.

• Lube Oil Fill Pipe and Strainer: Used when adding oil to the air-

oil receiver tank.

Low Oil Pressure Switch (optional) Switch contacts open when the fuel oil pressure drops below

selected pressure. Switch will interrupt the limit circuit upon loss of
sufficient fuel oil pressure for correct combustion.

Fuel Oil Pump Transfers fuel oil from the storage tank and delivers it under pres-

sure to the burner system.

FIGURE 2-5. Oil Control Valve Assembly - Light Oil

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2.5 — Controls Common to Oil-Fired Boilers

FIGURE 2-6. Oil Control Valve Assembly - Heavy Oil

FIGURE 2-7. Air Pump Components

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Burner Operation and Control

2.6 — Additional Controls for Heavy Oil

The oil heater is provided to heat heavy oil to the point where it can be effectively atomized and burned. Most
heavy oil heaters utilize an electric heater to reduce the viscosity of the heavy oil until steam or hot water is available
to the oil heater shell.

Heavy oil heaters, operating with hot water, will have additional controls.

Component Description

Heater Switch Manually provides power to the oil heater system.

Oil Heater (electric) Used for heating sufficient fuel oil for low-fire flow during cold

starts before steam or hot water is available for heating. The heater
must be turned off during extended boiler lay-up, or at any time the
fuel oil transfer pump is stopped.

Electric Oil Heater Thermostat Senses fuel oil temperature and energizes or de-energizes the elec-

tric oil heater to maintain required temperature of the fuel oil.

Steam Oil Heater Thermostat Senses fuel oil temperature and controls the opening and closing of

the steam heater valve to maintain the required temperature of the
fuel oil.

Oil Heater Shell (steam/hot water) Heats fuel oil through medium of steam or hot water. Electric

heater is housed in the steam heater, but is housed separately on a
hot water heater. Steam oil heaters on 15 psi boilers operate at boiler
pressure. Steam oil heaters furnished on high pressure boilers are to
be operated at less than 15 psi. Operation is accomplished with a
steam pressure regulator valve.

Oil Return Excess oil returned to the heavy oil supply tank.

Oil Inlet From Supply Tank Heavy oil inlet from the supply tank.

Steam Heater Check Valve Prevents oil contamination of the waterside of pressure vessel

should any leakage occur in the oil heater.

Steam Trap Drains condensate and prevents loss of steam from the steam oil

heater. Condensate must be piped to a safe point of discharge.

Check Valve (steam heater discharge) Prevents air entry during shutdown periods when cooling action

may create vacuum within steam heater.

Steam Heater Pressure Regulator Adjust to provide reduced (usually less than 15 psi) steam pressure

to the heater to properly maintain the required fuel oil temperature.
The regulator and the pressure gauge are not furnished on 15 psi
units.

Steam Heater Solenoid Valve A normally open solenoid valve opened by the steam oil heater ther-

mostat to allow flow of steam to the steam heater to maintain tem­perature of fuel oil.

Steam Pressure Gauge Indicates steam pressure entering the heater.

Oil Relief Valve allows release of excessive pressure to the return side of the oil line

piped to the tank.

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2.6 — Additional Controls for Heavy Oil

Component Description

Low Oil Temperature Switch Thermostatic switch that prevents burner from starting, or stops

burner firing if fuel oil temperature is lower than required for oil
burner operation.

Oil Supply Pressure Gauge Indicates fuel oil pressure in the oil heater and supply pressure to

the fuel oil controller’s pressure regulator.

FIGURE 2-8. Oil Heating Assembly (Steam)

In addition to the components of the fuel oil controller identified in section 2.5, the following are used with a heavy
oil fired burner.

Component Description

High Oil Temperature Switch (optional) Switch contacts open when fuel oil temperature raises above a

selected temperature. Switch will interrupt the limit circuit in the
event fuel oil temperature rises above the selected point.

Hot Water Oil Heater Thermostat Used on a hot water boiler to sense fuel oil temperature and control

the starting and stopping of the booster water pump.

Booster Water Pump Started and stopped by the hot water thermostat to regulate the

flow of hot water through the hot water oil heater to maintain tem­perature of fuel oil.

Fuel Oil Thermometer Indicates temperature of fuel oil being supplied to the fuel oil con-

troller.

Back Pressure Valve For adjustment of oil pressure on the downstream side of the

metering valve. Also regulates rate and return oil flow.

Oil Return Pressure Gauge Indicates oil pressure on the return side of the fuel oil controller.

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Burner Operation and Control

Component Description

Manual Bypass Valve Provided as a timer saver in establishing oil flow. When open, it per-

mits circulation of oil through the supply and return lines. The valve
MUST be closed prior to initial light off.

Orifice Oil Control Valve Valve may be opened prior to startup to aid in establishing fuel oil

flow through the controller. The valve MUST be closed prior to
initial light off. Its disc has an orifice to permit a continuous circula­tion of hot fuel oil through the controller.

Air Purge Valve Solenoid valve opens simultaneously with closing of oil solenoid

valve at burner shutdown, allowing compressed air to purge oil
from the burner nozzle and adjacent piping. The oil is burned by
the diminishing flame, which continues burning for approximately 4
seconds after the oil solenoid valve closes.

Air Purge Orifice Nozzle Limits purging air to proper quantity for expelling unburned oil at

normal delivery rate.

Air Purge Orifice Nozzle Filter Filters the purging air of any particles that might plug the air purge

orifice nozzle.

Air Purge Check Valve Valve check prevents fuel oil from entering the atomizing air line.

Air Purge Relay When energized, control operation of air purge valve.

2.7 — Controls for Combination Burners Only

Burners equipped to burn either oil or gas include equipment for each fuel. The Gas-Oil Selector Switch engages
the appropriate interlocks and controls for gas or oil operation. Chapter 4 details the required mechanical functions
of each fuel system.

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2.8 — Combustion Air

2.8 — Combustion Air

Air for combustion of fuel (referred to as “secondary” air) is furnished
by the forced draft fan mounted in the boiler head. In operation, air
pressure is built up in the entire head and is forced through a diffuser
plate for a thorough mixture with the fuel for proper combustion. The
supply of secondary air to the burner is governed by automatically throt­tling the output of the fan by regulating the rotary air damper. The
damper provides the proper amount of air for correct ratio of air to fuel
for efficient combustion at all firing rates.

FIGURE 2-9. Secondary Air Flow Diagram

2.9 — Automatic Ignition

Oil or gas burners are ignited by an interrupted type pilot. The pilot flame is ignited automatically by an electric
spark.

In the case of a combination burner, the gas pilot is used to ignite either the main gas flame or the oil flame.

At the beginning of the ignition cycle, and governed by the program relay, the pilot solenoid valve and ignition
transformer are simultaneously energized.

The ignition transformer supplies high voltage current for the igniting spark. A gas pilot has a single electrode and
a spark arcs between the tip of the electrode and the wall of the tube surrounding it. The pilot solenoid valve and
the transformer are de-energized after main flame is ignited and established.

Fuel for the gas pilot is supplied from the utility’s main, or from a tank (bottle) supply. Secondary air flows into and
mixes with the pilot gas stream to provide an adequate flame.

Insurance regulations may require two gas pilot solenoid valves with a normally open vent valve between them. The
vent valve closes when the gas pilot valves open, and opens when the gas pilot valves shut to vent gas, should any
be present in the pilot line during the de-energized period of the gas pilot valves.

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Burner Operation and Control

2.10 — Atomizing Air

Air for atomizing the fuel oil (referred to as “primary” air) is pumped by the air pump into the air-oil receiver tank
and delivered under pressure through a manifold block to the oil burner nozzle.

The atomizing air mixes with the fuel oil just prior to the oil leaving the nozzle.

Atomizing air pressure is indicated by the air pressure gauge on the burner gun.

Air pressure from the pump also forces sufficient oil from the tank to the pump bearings to lubricate them and also
to provide a seal and lubrication for the pump vanes. As a result, the air delivered to the tank contains some lube
oil, however, most of it is recovered through baffles and filters in the tank before the air passes to the burner.

Some of the primary air is also used to assist the oil pressure regulators of the fuel oil controller. Further explana­tion is given in chapter 5.

2.11 — Oil Fuel Flow: Light Oil

Fuel oil is delivered into the system by a supply pump which delivers part of its discharge to the oil burner. Excess
oil is returned to the oil storage tank through the fuel oil relief valve and oil return line. Normally the pump oper­ates only while the burner is in operation, although a positioning switch is often provided so that either continuous
or automatic pump operation can be obtained (See Figure 2-10).

The oil flows through a fuel oil strainer to prevent any foreign material from flowing through the control valves
and nozzle. The fuel oil controller contains in a single unit, a metering valve, a regulator, and a gauge required to
regulate the pressure and flow of oil to the burner. The adjustable regulator controls the pressure. To assist in the
regulation, back pressure is created by an orifice nozzle located in the oil return line immediately downstream of
the fuel oil controller.

The programming relay energizes or de-energizes the solenoid oil valves to permit or cut off oil flow to the burner.
Two valves, operating simultaneously, are used. The valves are closed when de-energized. They cannot be opened
(energized) unless the combustion air proving switch and the atomizing air proving switch are closed. The two
switches are satisfied, respectively, by sufficient combustion air pressure from the forced draft fan and pressurized
air from the air pump.

The oil flow to the burner is controlled by the movement of the metering stem in the oil metering valve, which var­ies the flow to meet load demands. The metering valve and the air damper are controlled simultaneously at all times
by the modulating motor to proportion combustion air and fuel for changes in load demand.

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2.11 — Oil Fuel Flow: Light Oil

FIGURE 2-10. Light Oil Flow Diagram

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Burner Operation and Control

2.12 — Oil Fuel Flow: Heavy Oil

Fuel oil is delivered into the system by the fuel oil supply pump which delivers part of its discharge to the oil heater.
The remainder of the fuel oil returns to the oil storage tank through a fuel oil relief valve and oil return line (see
Figure 2-11).

The combination electric and steam oil preheater is controlled by thermostats. The electric oil heater thermostat
energizes the electric heater, which is provided to supply heated oil on cold starts. The steam heater thermostat
controls operation of the steam solenoid valve to permit a flow of steam to the heater when steam is available.

A hot water boiler is equipped to heat the oil with hot water from the boiler, unless other preheating equipment is
utilized. The electric heater, which is housed separately, is sized to provide heated oil on a cold start. The hot water
thermostat controls the operation of a pump that supplies hot water to the oil heater when hot water is available.

The heated oil flows through a fuel oil strainer to prevent any foreign matter from entering the control valves and
nozzle.

The fuel oil controller contains, in a single unit, the necessary valves, regulators and gauges to regulate the pressure
and flow of oil to the burner.

The program relay energizes or de-energizes the solenoid oil valve to permit or cut off oil flow to the burner. The
oil solenoid is closed when de-energized. It cannot be opened (energized) unless the combustion air proving
switch, the atomizing air proving switch, and the low oil temperature and any pressure switches are closed. They
are satisfied, respectively, by sufficient combustion air pressure from the forced draft fan, pressurized air from the
air pump, and sufficient oil temperature and pressure.

Oil flow to the burner is controlled by the movement of the metering stem of the oil metering valve, which varies
the flow to meet load demands. The metering valve and the air damper are controlled simultaneously at all times by
the modulating motor to proportion combustion air and fuel for changes in load demand.

Oil is purged from the burner gun upon each burner shutdown. The air purge solenoid valve opens as the fuel
valve closes, diverting atomizing air through the oil line. The air assures a clean nozzle and line for subsequent
restart.

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2.12 — Oil Fuel Flow: Heavy Oil

FIGURE 2-11. No. 6 Heavy Oil Flow Diagram (Steam-Electric Heater)

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Burner Operation and Control

2.13 — Gas Fuel Flow

Metered gas from the utility flows through the pressure regulator at a reduced pressure suitable to burner require­ments, through the main gas shutoff cock, main gas valve(s), and modulating butterfly gas valve to the non-premix
orifice-type burner.

The main gas valve is of the normally closed type, and is opened (energized) in proper sequence by the program­ming relay.

The butterfly gas valve modulates the flow of gas from low through high fire settings. The position of the butterfly
valve disc is governed by the gas modulating cam. The butterfly gas valve, and the air control damper are controlled
simultaneously by the modulating motor to proportion combustion air and fuel for changes in load demand.

The gas flow rate required for rated burner input depends upon the heating value (Btu/cubic foot) of the gas sup­plied. The gas pressure regulator adjusts the gas pressure (flow rate) to the entrance of the gas train. The regulator
is not always supplied with the burner, but may be provided by others.

The main gas valves cannot be energized (opened) unless the combustion air proving switch is closed to indicate a
sufficient supply of combustion air. The low gas pressure and high gas pressure switches must be closed to prove
sufficient, but not excessive, gas fuel pressure.

2.14 — Modulating Firing

The modulating motor, through a linkage arrangement, controls the air damper and the butterfly gas valve, or the
oil metering valve, to maintain a constant air/fuel ratio throughout the firing range.

During burner operation, the motor is controlled by a modulating pressure control on a steam boiler, or by a mod­ulating temperature control on a hot water boiler. A manually operated potentiometer is provided to permit posi­tioning of the motor at the desired burner firing rate. The potentiometer is used primarily for initial or subsequent
checking and setting of fuel input. Normal operation should be with the manual-automatic switch in the “auto­matic” position and under the control of the modulating control.

The modulating motor (commonly called a damper motor) is reversible. It has an internal limit switch that restricts
shaft rotation to 90º. During normal operation the motor will move in either direction or stop at any position
within the range.

The motor potentiometer is electrically connected to a matching potentiometer in the modulating control. Chang­ing steam pressure or water temperature alters the electrical resistance of the modulating controller potentiometer.
The change in resistance compels an integral balancing relay to start, stop, or reverse the motor rotation. Rotation
in either direction continues until the resistance ratio of the two potentiometers is equal.

When the resistance ratio is equal, the motor stops in a position that allows the proper fuel and combustion air
flow to meet operating demands.

A feature designed into the circuitry maintains the modulating motor in the low-fire position during ignition and
keeps it there until the main flame is established. A low-fire switch, integral to the motor, is actuated by the rotation

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2.14 — Modulating Firing

of the motor. The switch must be closed to establish that the damper and fuel metering valves are in the low-fire
position before the programmer commences into the ignition period. During this time, neither the manual flame
control nor the modulating control have any control over the damper motor, regardless of their setting.

An optionally equipped boiler uses a second integral switch to establish that the motor has driven the damper to an
open position during the pre-purge period. The second integral switch closes, as high fire position is approached,
to complete an internal circuit in the programmer to allow continuation of the programming cycle.

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Burner Operation and Control

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CHAPTER 3 Waterside Care and

Requir ements

3.1 — Overview

The operator should be familiar with this chapter before attempting to place the unit into operation.

Although it is of prime importance, the subject of water supply and treatment cannot adequately be covered in this
manual. For specific information or assistance with your water treatment requirements, contact your Cleaver­Brooks service and parts representative.

Feedwater equipment should be checked and ready for use. Be sure that all valves, piping, boiler feed pumps, and
receivers are installed in accordance with prevailing codes and practices.

Water requirements for both steam and hot water boilers are essential to boiler life and length of service. It is vital
care be taken in placing the pressure vessel into initial service. The waterside of new boilers and new or remodeled
steam or hot water systems may contain oil, grease, or other foreign matter. A method of boiling out the vessels to
remove the accumulations is described later in this chapter.

Boilers, as a part of a hot water system, require proper water circulation. The system must be operated as intended
by its designer in order to avoid thermal shock or severe, possibly damaging, stresses from occurring to the pres­sure vessel.

NOTE: This manual only covers boilers using water. Glycol solutions have different operating requirements, circula­tion rates, temperatures, etc.

3.2 — Water Requirements: Hot Water Boiler

3.2.1 — Air Removal

The hot water outlet includes a dip tube which extends 2 to 3 inches into the boiler. The dip tube reduces the pos­sibility of air, which may be trapped at the top of the shell, from entering into the system. Oxygen or air released in
the boiler will collect or be trapped at the top of the boiler shell.

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Waterside Care and Requirements

The air vent tapping on the top center line of the boiler should be piped into the expansion or compression tank.
Air trapped at the top of the boiler will find its way out of the boiler through the tapping.

3.2.1.1 — Minimum Water Temperature

The minimum recommended boiler water temperature is 170º F. When water temperatures lower than 170º F are
used, the combustion gasses are reduced in temperature to a point where water vapor condenses, causing corrosion
in the boiler and possible breeching.

Condensation is more severe on a unit that operates intermittently and which is greatly oversized for the actual
load. Condensation can be minimized by maintaining the boiler water temperatures above 170º F.

A temperature of 170º F is also recommended in order to provide a sufficient “temperature head” when No. 6 fuel
oil is to be heated to the proper atomizing temperature by the boiler water in a safety-type oil preheater. (The elec­tric preheater on the boiler must provide additional heat to the oil if boiler water temperature is not maintained
above 200º F.

NOTE: If the operating water temperature going to the system must be lower than 170º F, the operating boiler water
temperature should be a minimum of 170º F (200º F if used to preheat No. 6 oil) and mixing valves should be used to
avoid damage to the equipment.

3.2.1.2 — Rapid Replacement of Boiler Water

The system layout and controls should be arranged to prevent the possibility of pumping large quantities of cold
water into a hot boiler, which will cause shock or thermal stresses. Water temperature in a boiler of 200º F or 240º
F cannot be completely replaced with 80º F water in a few minutes time without causing thermal stress. The same
fact applies to periods of normal operation, as well as during initial startup.

NOTE: The circulating pumps should be interlocked with the burner so that the burner cannot operate unless the cir­culating pump is running in order to avoid damage to the equipment.

When individual zone circulating pumps are used, it is recommended that they be kept running, even though the
hear users do not require hot water. The relief device or bypass valve will thus allow continuous circulation through
the boiler and can help prevent rapid replacement of boiler water with cold zone water.

3.2.1.3 — Continuous Flow Through the Boiler

The system should be piped and the controls arranged to allow water circulation through the boiler under all oper­ating conditions. The operation of three-way valves and system controls should be checked to be sure that the
boiler will not be bypassed. Constant circulation through the boiler eliminates the possibility of stratification within
the unit and results in more even water temperatures to the system.

A rule of thumb of 3/4 to 1 gpm per boiler horsepower can be used to determine the minimum continuous flow
rate through the boiler under all operating conditions. The operator should determine that a flow of water exists
through the boiler before initial firing or refiring after the boiler has been drained.

3.2.2 — Water Circulation

The following chart shows the maximum gpm circulation rate of boiler water in relation to full boiler output and
system temperature drop.

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3.2 — Water Requirements: Hot Water Boiler

BOILER

SIZE

(BHP)

15 500 100 50 33 25 20 17 14 12 11 10
20 670 134 67 45 33 27 22 19 17 15 13
30 1,005 200 100 67 50 40 33 29 25 22 20
40 1,340 268 134 89 67 54 45 38 33 30 27
50 1,675 335 168 112 84 67 56 48 42 37 33
60 2,010 402 201 134 101 80 67 58 50 45 40
70 2,345 470 235 157 118 94 78 67 59 52 47

80 2,680 536 268 179 134 107 90 77 67 60 54
100 3,350 670 335 223 168 134 112 96 84 75 67
125 4,185 836 418 279 209 168 140 120 105 93 84
150 5,025 1,005 503 335 251 201 168 144 126 112 100
200 6,695 1,340 670 447 335 268 224 192 168 149 134
250 8,370 1,675 838 558 419 335 280 240 210 186 167
300 10,045 2,010 1,005 670 503 402 335 287 251 223 201
350 11,720 2,350 1,175 784 587 470 392 336 294 261 235
400 13,400 2,680 1,340 895 670 535 447 383 335 298 268
500 16,740 3,350 1,675 1,120 838 670 558 479 419 372 335
600 20,080 4,020 2,010 1,340 1,005 805 670 575 502 448 402
700 23,430 4,690 2,345 1,565 1,175 940 785 670 585 520 470
800 26,780 5,360 2,680 1,785 1,340 1,075 895 765 670 595 535

BOILER OUT-

PUT (1000)

BTU/HR

SYSTEM TEMPERATURE DROP - DEGREES °F

10 20 30 40 50 60 70 80 90 100

MAXIMUM CIRCULATING RATE - GPM

FIGURE 3-1. Maximum Circulating Rate Chart

3.2.2.1 — Multiple Boiler Installations

When multiple boilers are used, care must be taken to ensure adequate or proportional flow through the boilers.
Proportional flow can best be accomplished by use of balancing valves and gauges in the supply line from each
boiler. If balancing valves or orifice plates are used, a significant pressure drop (3 to 5 psi) must be taken across the
balancing device to accomplish the purpose.

If care is not taken to ensure adequate or proportional flow through the boilers, wide variations in firing rates
between the boilers can result.

In extreme cases, one boiler may be in the high-fire position while the other boiler or boilers may be at low-fire.
The net result would be that the common header water temperature to the system would not be up to the desired
point.

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3.2.2.2 — Pump Location

It is recommended that the system circulating pumps take suction from the outlet connection on the boiler, and
that they discharge to the system load in order to put the boiler and the expansion tank on the suction side of the
pump. The suction side is preferred because it decreases air entry into the system and does not impose the system
head on the boiler.

It is common practice to install a standby system circulating pump. The main circulating pumps are usually located
adjacent to the boilers in the boiler room.

3.2.2.3 — Pump Operation

Pumps are normally started and stopped by manual switches. It is also desirable to interlock the pump with the
burner so that the burner cannot operate unless the circulating pump is running.

3.2.3 — Pressure

The design of the system and usage requirements often dictate the pressure exerted upon the boiler. Some systems
are pressurized with air, or with an inert gas such as nitrogen. Caution must be exercised to ensure that the proper
relationship of pressure-to-temperature exists within the boiler so that all of the boiler’s internal surfaces are fully
wetted at all times. For this reason, the internal boiler pressure, as indicated on the water pressure gauge, must be
held to the level identified on Figure 3-2.

FIGURE 3-2. Internal Boiler Pressure

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3.3 — Water Requirements: Steam Boiler

When initially firing a newly installed boiler, or when cutting an existing boiler into an operating system, the boiler
or boilers to be cut into operation MUST be pressurized equal to the system and/or other boilers prior to opening
the header valves.

It is advisable to have a thermometer installed in the return line to indicate return water temperature. Knowing the
supply water temperature, the boiler system differential can be established. With knowledge of the pumping rate,
the operator can easily detect any excessive load condition and take appropriate corrective action.Special caution
must be taken to guard against any condition, or combination of conditions, that might lead to the transfer of cold
water to a hot boiler or hot water to a cold boiler. It cannot be over emphasized that rapid changes in temperature
within the boiler can, and sometimes do, cause damage.

3.3 — Water Requirements: Steam Boiler

3.3.1 — Feed Pump Operation

BEFORE turning on the pump motor be certain that all valves in the water feed line are open to prevent possible
damage to the feed pump mechanism. After opening the valves, momentarily energize the feed pump motor to
establish correct pump rotation. With the correct rotation established, close the boiler feed pump entrance switch.
The pump should shut down when the water level reaches the proper level (see Figure 3-3).

FIGURE 3-3. Low Water Cutoff Sight Gauge

Feedwater pumps must have adequate capacity to maintain required water level under all operating conditions.
Check the feedwater pumps periodically and maintain as necessary to prevent unexpected breakdowns.

NOTE: Prior to operating the pump, carefully check the alignment of the flexible coupling, if one is used. A properly
aligned coupling will last a long time and provide trouble-free mechanical operation.

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3.3.2 — Water Feeder (optional) Operation

Water feeder operation is usually applicable to boilers operating at 15 psi steam or less. It is only necessary to open
the water supply line valve and the water feeder discharge valve.

NOTE: In the event that water column isolation valves are provided or installed, it must be established that the valves
are open and seated or locked in the open position. If the valves are installed, it is illegal to operate the boiler with
closed or unsealed open valves.

Warning

!

The isolation valves and the water column piping must be locked open during operation. Failure to do so may result in
a low water condition. Failure to follow these instructions could result in serious injury or death.

3.4 — Water Treatment

Properly treated boiler feed water, coupled with good engineering and operating practices, lead to maximum effec­tiveness and long trouble-free life of pressure vessels, at the lowest operating cost. Contact your local Cleaver­Brooks authorized representative for information on how to prevent the presence of unwanted solids and corro­sive gasses.

Objectives of water treatment in general are:

• Prevent hard scale deposits or soft sludge deposits, which reduce heat transfer and can lead to overheated metal

and costly downtime and repairs.

• eliminate corrosive gasses in the supply or boiler water.

• Prevent intercrystalline cracking or caustic embrittlement of boiler metal.

• Prevent carryover and foaming.

Accomplishment of the above objectives generally requires proper feedwater treatment before and after introduc­tion of the water into the boiler. The selection of pre-treatment processes depends upon the water source, its
chemical characteristics, amount of makeup water needed, plant operating practices, etc. Treating methods include
filtering, softening de-mineralizing, deaerating, and preheating. After-treatment involves chemical treatment of the
boiler water.

Because of the variables involved, no single boiler compound can be considered a “cure-all” nor is it advisable to
experiment with homemade treating methods. Sound recommendations and their employment should be aug­mented by a periodic analysis of the feedwater, boiler water, and condensate.

The internal or waterside surfaces of the pressure vessel should be inspected with enough frequency to determine
the presence of any contamination, accumulations of foreign matter, corrosion, and/or pitting. If any of the condi­tions are detected, contact your local Cleaver-Brooks authorized representative for advice on corrective action.

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3.5 — Cleaning

A properly sized water meter should be installed in the raw water make-up line in order to accurately determine the
amount of raw water admitted to the boiler (steam or hot water) and to aid in maintaining proper waterside condi­tions.

3.5 — Cleaning

3.5.1 — Hot Water and Steam Piping

Steam and water piping systems connected to the boiler may contain oil, grease, or foreign matter. The impurities
must be removed in order to prevent damage to pressure vessel heating surfaces. On a steam system, the conden­sate should be wasted until tests show the elimination of undesirable impurities. During the periods that condensate
is wasted, attention must be given to the treatment of the raw water used as make-up so that an accumulation of
unwanted materials or corrosion does not occur. For more information, contact your local Cleaver-Brooks autho­rized representative.

On a hot water system, chemical cleaning is generally necessary and the entire system should be drained after treat­ment. Consult your local Cleaver-Brooks authorized representative for recommendations, cleaning compounds,
and application procedures.

3.5.2 — Pressure Vessel

The waterside of the pressure vessel must be kept clean from grease, sludge, and foreign material. Such deposits, if
present, will shorten the life of the pressure vessel, will interfere with efficient operation and functioning of control
of safety devices, and quite possibly cause unnecessary and expensive re-work, repairs, and downtime.

The installation and operating conditions that the boiler will be subjected to should be considered and cleaning of
the waterside of the pressure vessel should be provided during the course of initial start-up.

The pressure vessel and the steam and return lines or hot water piping represent, in effect, a closed system.
Although the steam and return (condensate) lines or the hot water piping system may have been previously cleaned,
it is possible that:

• Cleaning has been inadequate.

• Partial or total old system is involved.

• Conditions may prevent adequate cleaning of piping.

The pressure vessel waterside should be inspected on a periodic basis. An inspection will reveal true internal condi­tions and serve as a check against conditions indicated by chemical analysis of the boiler water. Inspection should
be made three months after initial starting and at regular 6-, 9-, or 12-month intervals thereafter. The frequency of
further periodic inspections will depend upon the internal conditions found.

If any unwanted conditions are observed, contact you local Cleaver-Brooks authorized representative for recom­mendations.

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Any sludge, mud, or sediment found will need to be flushed out. If excessive mud or sludge is noticed during the
blowdown, the scheduling or frequency of blowdown may need to be revised. The need for periodic draining or
washout will also be indicated.

Any oil or grease present on the heating surfaces should be removed promptly by a boil-out with an alkaline deter­gent solution.

NOTE: Temperature of initial fill of water for hydrostatic tests, boil-out, or for normal operation should be as stated
in the ASME Boiler Code.

3.6 — Boil-Out of a New Unit

The internal surfaces of a newly installed boiler may have oil, grease, or other protective coatings used in manufac­turing. Such coatings must be removed because they lower the heat transfer rate and could cause over-heating of a
tube. Before boiling out procedures may begin, the burner should be ready for firing. The operator must be familiar
with the procedure outlined under burner operation.

Warning

!

Use of a suitable face mask, goggles, rubber gloves, and protective garments is strongly recommended when handling
or mixing caustic chemicals. Do not permit the dry material or the concentrated solution to come in contact with skin
or clothing. Failure to follow these instructions could result in serious injury or death.

Your local Cleaver-Brooks authorized representative will be able to recommend a cleaning or boil-out procedure.
In the event such service is unavailable or is yet unscheduled, the following information may be of assistance.

Several chemicals are suitable for boil-out. One combination often used is soda ash (sodium carbonate) and caustic
soda (sodium hydroxide) at the rate of 3 to 5 pounds each per 1,000 pounds of water, along with a small amount of
laundry detergent added as a wetting agent.

The suggested general procedure for cleaning a boiler is (refer to Figure 3-4 to determine water capacity):

1. Have sufficient cleaning material on hand to complete the job.

2. When dissolving chemicals:

a) warm water should be put into a suitable container

b) slowly introduce the dry chemical into the water, stirring at all times until completely dissolved

c) add the chemical slowly and in small amounts to prevent excessive heat and turbulence

3. An overflow pipe should be attached to one of the top boiler openings and routed to a safe point of discharge.

A relief or safety valve tapping is usually used.

4. Water relief valves and steam safety valves must be removed before adding the boil-out solution so that neither

it nor the grease which it may carry will contaminate the valves. Use care in removing and reinstalling the valves.
(Refer to Chapter 8, section 8.-13 for valve installation instructions.)

5. All valves in the piping leading to or from the system must be closed to prevent the cleaning solution form get-

ting into the system.

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3.6 — Boil-Out of a New Unit

6. Fill the pressure vessel with clean water until the top of the tubes is covered. Add the cleaning solution and then

fill to the top. The temperature of the water used in the initial fill should be at ambient temperature.

7. The boiler should then be fired intermittently at a low rate sufficient to hold solution just at the boiling point.

Boil the water for at least five hours. Do not produce steam pressure.

Water - Gallons Wate r - Weight

Generator Sizes

250 HP 1280 1665 10670 13880

300 HP 1560 2020 13000 16840

350 HP 1855 2410 15465 20090

FIGURE 3-4. Water Capacity and Weights

8. Allow a small amount of fresh water to enter the boiler to create a slight overflow that will carry off surface

Normal Flooded Normal Flooded

impurities.

9. Continue the boil and overflow process until the water clears. shut the burner down.

10. Let the boiler cool to 120º F or less.

Warning

!

Be sure to drain the hot water to a safe point of discharge to avoid scalding. Failure to follow these instructions could
result in serious injury or death.

11. Remove handhole plates and wash the waterside surfaces thoroughly using a high pressure water stream.

12. Inspect the surfaces. If they are not clean, repeat the boil-out.

13. After closing the handholes and reinstalling the safety or relief valves, fill the boiler and fire it until the water is

heated to at least 180º F to drive off any dissolved gasses, which might otherwise corrode the metal.

The above procedure may be omitted in the case of a unit previously used or known to be internally clean. How­ever, consideration must be given to the possibility of contaminating materials entering the boiler from the system.

On a steam system, the condensate should be wasted until tests show the elimination of undesirable impurities.
During the period that condensate is wasted, be sure make-up water is treated to prevent an accumulation of
unwanted materials or corrosion.

On a hot water system, chemical cleaning is generally necessary and the entire system should be drained after treat­ment. Consult your local Cleaver-Brooks authorized representative for recommendations, cleaning compounds,
and application procedures.

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3.7 — Washing Out

3.7.1 — Hot Water Boiler

In theory, a hot water system and boiler that has been initially cleaned, filled with raw water (and water treated), and
with no make-up water added, will require no further cleaning or treatment. However, since the system (new or
old) can allow entrance of air and unnoticed or undetected leakage of water, introductions of raw water make-up or
air may lead to pitting, corrosion, and formation of sludge, sediment, scale, etc. on the pressure vessel waterside.

If the operator is absolutely certain that the system is tight, then an annual waterside inspection may be sufficient.
However, if there is any doubt, the pressure vessel waterside should be inspected no later than three months after
initially placing the boiler into operation, and periodically thereafter as indicated by conditions observed during
inspections.

3.7.2 — Steam Boiler

No later than three months after initially placing the boiler into operation and starting service, and thereafter as
conditions warrant, the pressure vessel should be drained after being properly cooled to near ambient temperature.
Handhole covers should be removed and waterside surfaces should be inspected for corrosion, pitting, or forma­tion of deposits.

3.7.3 — Flushing of Pressure Vessel Interior

Upon completion of the inspection, the pressure vessel interior should be flushed out, as required, with a high
pressure hose. If deposits are not fully removed by flushing, a consultation may be required with your local Cleaver­Brooks authorized representative. In extreme cases, it may be necessary to resort to acid cleaning. Professional
advice is recommended if acid cleaning is required.

The inspections will indicate the effectiveness of the feedwater treatment. The effectiveness of treatment, the water
conditions, and the amount of fresh water make-up required are all factors to be considered in establishing fre­quency of future pressure vessel washouts. Contact your local Cleaver-Brooks authorized representative for more
information.

3.8 — Blowdown: Steam Boiler

Boiler water blowdown is the removal of some of the concentrated water from the pressure vessel and its replace­ment with feedwater so that the lowering of the concentration of solids in the boiler water occurs.

Solids are brought in by the feedwater even though the water is treated prior to use through external processes that
are designed to remove unwanted substances which contribute to scale and deposit formations. However, none of
the processes can remove all substances. Regardless of their high efficiency, some solids will be present in the boiler
feedwater.

Solids become less soluble in the high temperature of the boiler water and tend to accumulate on heating surfaces.
Therefore, blowdown and internal chemical treatment are required to prevent the solids from forming harmful
scale and sludge.

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3.8 — Blowdown: Steam Boiler

Scale has a low heat transfer value and acts as an insulation barrier. Scale retards heat transfer, which not only
results in lower operating efficiency, and consequently higher fuel consumption, but more importantly, can cause
overheating of boiler metal. Overheating of boiler metal can result in tube failures or other pressure vessel metal
damage and lead to boiler down-time and costly repairs.

Scale is caused primarily be calcium and magnesium salts, silica, and oil. Any calcium and magnesium salts in the
boiler water are generally precipitated by the use of sodium phosphate, along with organic materials, to maintain the
precipitates or “sludge” in a fluid form. The solids such as sodium salts and suspended dirt don not readily form
scale. But as the boiler water boils off as relatively pure steam, the remaining water is thickened with the solids. If
the concentration is permitted to accumulate, foaming and priming will occur and the sludge can cause harmful
deposits that bring about overheating of the metal.

The lowering or removal of the concentration requires the use of boiler water blowdown. The two principal types
of blowdown are intermittent manual blowdown and continuous blowdown.

3.8.1 — Intermittent Manual Blowdown

Manual or sludge blowdown is necessary for the operation of the boiler regardless of whether or not continuous
blowdown is employed.

The blowdown tappings are located at the bottom or lowest part of the boiler in order to lower the dissolved solids
in the pressure vessel water, and to remove a portion of the sludge that accumulates in the lower part of the vessel.

Equipment generally consists of a quick opening valve and a shutoff valve. The valves and necessary piping are not
normally furnished with the boiler, but supplied by others. All piping must be to a safe point of discharge. Piping
must be properly supported and free to expand.

3.8.2 — Continuous Blowdown

Continuous blowdown is used in conjunction with a surface blow-off tapping (furnished on 60” diameter and
larger units) and is the continuous removal of concentrated water.

The surface blow-off opening, when furnished, is on the top center line of the pressure vessel. It is provided with
an internal collecting pipe terminating slightly below the working water level for the purpose of skimming surface
sediment, oil, or other impurities from the surface of the pressure vessel water.

A controlled-orifice valve is used to allow a continual, yet controlled, flow of concentrated water.

Periodic adjustments are made to the valve setting to increase or decrease the amount of blowdown in accordance
with the test analysis.

The flow control valve and piping are generally provided by others. All piping must be to a safe point of discharge.

3.8.3 — Frequency of Manual Blowdown

When continuous blowdown is utilized, manual blowdown is primarily used to remove suspended solids or sludge.
The continuous blowdown removes sediment and oil from the surface of the water along with a prescribed amount
of dissolved solids.

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Waterside Care and Requirements

When surface or continuous blowdown is not utilized, manual blowdown is used to control the dissolved or sus­pended solids in addition to the sludge.

In practice, the valve(s) of the bottom blowdown are opened periodically in accordance with an operating schedule
and/or chemical control tests. From the standpoint of control, economy and results, frequent short blows are pre­ferred to infrequent lengthy blows. The length and frequency of the blowdown is particularly important when the
suspended solids content of the water is high. With the use of frequent short blows a more uniform concentration
of the pressure vessel water is maintained.

In cases where the feedwater is exceptionally pure, or where there is a high percentage of return condensate, blow­down may be employed less frequently since less sludge accumulates in the pressure vessel. When dissolved and/or
suspended solids approach or exceed predetermined limits, manual blowdown to lower the concentrations is
required.

It is generally recommended that a steam boiler be blown down at least once in every eight-hour period, but fre­quency may vary depending upon water and operating conditions. The blowdown amounts and schedule should be
recommended by your local Cleaver-Brooks authorized representative.

A hot water boiler does not normally include openings for surface blowdown and bottom blowdown since blow­downs are seldom practiced. The need remains to be alert to system water losses and corresponding amount of raw
water make-up. A water meter is recommended for water make-up lines.

3.8.4 — Manual Blowdown Procedure

Blowdown is most effective at a point when the generation of steam is at the lowest rate and feedwater input is also
low, thus providing a minimum dilution of the boiler water with low concentration feedwater.

1. Be sure the blow-off piping and tank, if used, are in proper operating condition. Discharge vents should be clear

of obstruction, and the waste should be piped to a point of safe discharge.

Most blow-off lines are provided with two valves, generally a quick opening valve nearest the boiler and slow
opening globe type valve downstream. Valves will vary depending upon pressure involved and make or manu­facturer. If seatless valves are installed, follow the manufacturer’s recommendations.

If a quick opening valve and globe type of slow opening valve are in combination, the former is normally
opened first and closed last with blow down accomplished with the globe or slow opening valve.

2. When opening the second or downstream valve, crack it slightly to allow the lines to warm, then continue open-

ing slowly.

Caution

!

Do not pump the lever action valve open and closed, as water hammer is apt to break the valve bodies or pipe fittings.
Failure to follow these instructions could cause damage to the equipment.

The length of each blow should be determined by actual water analysis. Lowering the water in the gauge glass
approximately 1/2” is often acceptable as a guide to adequate blow. However, lowering the water 1/2” should
not be interpreted as a rule since water analysis procedures should prevail. If the glass cannot be viewed by the
party operating the valve, another operator should watch the glass and direct the valve operator.

3. Close the downstream (slow opening) valve first and as fast as possible.

4. Close the valve next to the boiler.

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3.9 — Periodic Inspection

5. Slightly crack the downstream valve and then close it tightly.

Under not circumstances should a blow-off valve be left open and the operator should never leave until the blow­down operation is completed and the valves are closed.

3.9 — Periodic Inspection

Insurance regulations or local laws will require a periodic inspection of the pressure vessel by an authorized inspec­tor. Sufficient notice is generally given to permit removal of the boiler from service and preparation for inspection.

Warning

!

To avoid the hazard of electrical shock, we recommend the use of a low voltage flashlight during an internal inspection.
Preferably, inspectors should work in pairs. Failure to follow these instructions could result in serious injury or death.

When shutting down the boiler, the load should be reduced gradually and the pressure vessel cooled at a rate that
avoids damaging temperature differential that can cause harmful stresses. Vessels should not normally be drained
until all pressure is relieved - to prevent uneven contraction and temperature differentials that can cause expanded
tubes to leak. Draining the unit too quickly may cause the baking of deposits that may be present on the heating
surfaces. Some heat, however, may be desirable to dry out the interior of the boiler.

If the internal inspection is being made at the request of an authorized inspector, it is well to ask the inspector
observe the conditions prior to cleaning or flushing of waterside surfaces.

Be certain that a supply of manhole and handhole gaskets is available, along with any other gaskets or items needed
to place the unit back into operation after inspection.

Have available information on the boiler design, dimensions, generating capacity, operating pressure or tempera­ture, time in service, defects found previously, and any repairs or modifications. Also have available for reference
records of previous inspections.

Be prepared to perform any testing required by the inspector including a hydrostatic test.

After proper cooling and draining of the vessel, flush out the waterside with a high pressure water hose. Remove
any scale or deposits from the waterside surfaces and check for internal or external corrosion and leakage.

The fireside surface should also be thoroughly cleaned so that metal surfaces, welds, joints, tube ends, fittings and
any previous repairs can be readily checked.

Be sure that steam valves, and valves to expansion tank (hot water), feedwater valves, blow-off valves, all fuel valves,
and electrical switches are shut off prior to opening handholes, manhole, and front or rear doors. Adequately vent
the pressure vessel prior to entry.

Clean out the low-water cutoff piping, the water level controls and cross-connecting pipes. Replace the water gauge
glass and clean out the water cocks. Also check and clean the drain and the blowdown valves and piping.

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Waterside Care and Requirements

Check all water and steam piping and valves for leaks, wear, corrosion, and other damage. Replace or repair as
required.

3.10 — Preparation for Extended Lay-Up

Many boilers used for heating or seasonal loads or for standby service may have extended periods of non-use. Spe­cial attention must be given to idle boilers so that neither waterside nor fireside surfaces are allowed to deteriorate
from corrosion.

Too many conditions exist to lay down definite rules. There are two methods of storage: wet or dry. Your local
Cleaver-Brooks authorized representative can recommend the better method depending upon circumstances in the
particular installation.

Whichever method is used, common sense dictates a periodic recheck of fireside and waterside conditions during
lay-up to allow variations from the above methods for special area or job-site conditions.

Swing open the boiler head at the stack end of the unit to prevent flow of warm, moist air through the boiler tubes.

Although pollution control regulations may continue to limit the permissible sulphur content of fuel oils, care must
be taken to avoid corrosion problems that sulphur can cause, especially in a boiler that is seasonally shut down.
Dormant periods, and even frequent shutdowns, expose the fireside surfaces to condensation below the dew point
during cooling. Moisture and any sulphur residue can form an acid solution. Under certain conditions, and espe­cially in areas with high humidity, the corrosive effect of the acid will be serious enough to eat through or severely
damage boiler tubes or other metal heating surfaces during the time that a boiler is out of service.

The condition does not generally occur during normal firing operation, because the high temperature of operation
vaporizes any condensation. However, proper boiler operation must be maintained, especially with a hot water
boiler, to prevent the flue gasses from falling below the dew point.

At the start of lay-up, thoroughly clean the fireside by removing any soot or other products of combustion from
the tubes, tube sheets, and other fireside surfaces. Brushing will generally suffice. Sweep away or vacuum any accu­mulation. The fireside surfaces may be flushed with water. However, all moisture must be eliminated after flushing
and the surface dried by blowing air or applying some form of heat. It is good practice to protect the cleaned sur­faces by coating them with an anti-corrosive material to prevent rust.

T prevent condensation from forming in the control cabinet, keep the control circuit energized. For extended lay­up periods, especially where high humidity or large swings in ambient temperature occur, the control should be
removed and stored in a dry atmosphere.

Dry storage is generally employed when the boiler will be out of service for a significant period of time, or where
freezing temperatures may exist. In the dry storage method the boiler must be thoroughly dried because any mois­ture would cause corrosion. Both fireside and waterside surfaces must be cleaned of all scale, deposits, soot, etc.
Steps must be taken to eliminate moisture by placing moisture-absorbing materials such as quick lime (at 2 pounds
for 3 cubic feet of volume) or silica gel (at 5 pounds for 30 cubic feet of volume) on trays inside the vessel. Fireside
surfaces may be coated with an anti-corrosive material, or grease or tar paint. Refractories should be brushed clean
and wash-coated. All openings to the pressure vessel, such as manhole and handholes, should be shut tightly. Feed-

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3.10 — Preparation for Extended Lay-Up

water and steam valves should be closed. Damper and vents should be closed to prevent air from reaching fireside
surfaces. Periodic inspection should be made and absorption materials renewed.

Wet storage is generally used for a boiler held in stand-by condition or in cases where dry storage is not practical.
The possibility of freezing temperatures must be considered. Care must again be taken to protect metal surfaces.
Variables preclude definite recommendations. However, it is suggested that the pressure vessel be drained, thor­oughly cleaned internally, and re-filled to overflowing with treated water. If deaerated water is not available, the unit
should be fired to boil the water for a short period of time. Additional chemicals may be suggested by your local
Cleaver-Brooks authorized representative to minimize corrosion. Internal water pressure should be maintained at
greater than atmospheric pressure. Nitrogen is often used to pressurize the vessel. Fireside surfaces must be thor­oughly cleaned and the refractory should be wash-coated.

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Waterside Care and Requirements

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CHAPTER 4 Sequence of Operation

4.1 — Overview

Chapter 4 outlines the electrical sequencing of various controls through the pre-purge, ignition, run, and shutdown
cycles of the burner.

The program relay establishes the sequence of operation and directs the operation of all other controls and compo­nents to provide an overall operating sequence.

NOTE: The make or model of the program relay provided will vary depending upon job specifications. The following
sequence applies regardless of the make or model. Please refer to the Wiring Diagram (WD) prepared by Cleaver­Brooks for your specific installation.

The burner and control system are in starting condition when the following conditions exist:

• Boiler water is up to the correct level, closing the low-water cutoff switch.

• The low-water light (panel) is off.

• The operating limit pressure control (steam boiler) or the operating limit temperature control (hot water boiler)

and high limit pressure or temperature control are below their cutoff setting.

• All applicable limits are correct for burner operation.

• The load demand light is on.

All entrance switches should be closed and power should be present at the line terminals of::

• Blower motor starter

• Air compressor motor starter (if provided)

• Oil heater relay (if provided)

• Oil pump motor starter (if provided)

The sequences do not attempt to correlate the action of the fuel supply system or feedwater system except for the
interlock controls that directly relate to the action of the program relay. Chapters 5 and 6 contain operating instruc­tions and specific information on setting and adjusting the controls.

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Sequence of Operation

4.2 — Circuit and Interlock Controls

The burner control circuit is a two-wire system designed for 115 Vac, 60 Hz, single-phase power.

The electrical portion of the boiler is made up of individual circuits with controls that are wired in a manner
designed to provide a safe workable system. The program relay provides connection points for the interconnection
of the various circuits.

The controls used vary depending upon the fuel oil or gas and the specific requirement of applicable regulatory
bodies. Refer to the boiler wiring diagram to determine the actual controls provided. The circuits and controls nor­mally used in the circuits are identified in the following table and are referred to in Section 4.3.

Circuit Components

Limit Circuit

Blower Motor Starter Circuit

Running Interlock Circuit

Low Fire Proving Circuit

Pilot Ignition Circuit

Flame Detector Circuit

• Burner switch (BS)

• Operating limit control (OLC) - pressure or temperature

• High limit control (HLC) - pressure or temperature

• Low-water cutoff (LWCO)

• Gas-oil selector switch (GOS) - combination burner only

• Oil drawer switch (ODS) - oil burner

• Low oil temperature switch (LOTS) - nos. 5 and 6 oil only

• Low gas pressure switch (LGPS)

• High gas pressure switch (HGPS)

• LE proximity switch interlock

• Fuel valve interlock circuit

• Main gas valve auxiliary switch (MGVAS)

• Oil valve auxiliary switch (OVAS)

• Blower motor starter (BMS)

• Air compressor motor starter (ACMS) - if provided

• Air purge valve (APV) - nos. 5 and 6 oil only

• Blower motor starter interlock (BMSI)

• Combustion air proving switch (CAPS)

• Atomizing air proving switch (AAPS) - if provided

• Low fire switch (LFS)

• Gas pilot valve (GPV)

• Ignition transformer (IT)

• Gas pilot vent valve (GPVV) - if provided

• Flame detector (FD)

• Main fuel valve circuit

• Main gas valve (MGV)

• Main gas vent valve (MGVV) - if provided

• Oil valve (OV)

• Main fuel valve light (FVL)

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4.3 — Sequence of Operation: Oil or Gas

Circuit Components

Firing Rate Circuit

• Damper motor transformer (DMT)

• Modulating damper motor (MDM)

• Manual-automatic switch (MAS)

• Manual flame control (MFC)

• Modulating control (MC)

High Fire Proving Circuit

Running Interlock and Limit Circuit

• High fire switch (HFS)

• Low oil pressure switch (LOPS)

• High oil pressure switch (HOPS)

• High oil temperature switch (HOTS)

• Auxiliary low-water cutoff (ALWCO)

To comply with requirements of insurance underwriters such as FM Global (Factory Mutual), XL GAP (GE GAP/
IRI), or others, additional interlock devices may be used.

4.3 — Sequence of Operation: Oil or Gas

On a combination fuel unit, the gas/oil switch must be set for the proper fuel.

The following sequence occurs with power present at the program relay (PR) input terminals and with all other
operating conditions satisfied.

4.3.1 — Pre-Purge Cycle

When the burner switch (BS) is turned “on,” and controls wired in the “limit” and “fuel valve interlock” circuits are
closed and no flame signal is present, the “blower motor start circuit” is powered energizing the blower motor
starter (BMS). The load demand light (LDL) turns on. When firing oil, the air compressor motor starter (ACMS - if
provided) is also powered. The air purge valve (APV - nos. 5 and 6 oil only) remains de-energized.

At the same time, the program relay signals the modulating damper motor (MDM) to open the air damper. The
damper begins to open and drives to its full open or high fire position. Opening the damper motor allows a flow of
purging air through the boiler prior to the ignition cycle.

On certain boilers the circuitry will include a high fire switch (HFS). The purpose of the switch is to prove that the
modulating damper motor (MDM) has driven the damper to the open position during the pre-purge cycle. In this
instance, the “high fire proving circuit” is utilized.

The controls wired into the “running interlock circuit” must be closed within 10 seconds after the start sequence.
In the event any of the controls are not closed at this time, or if they subsequently open, the program relay will go
into a safety shutdown.

At the completion of the high fire purge period, the program relay signals the modulating damper motor (MDM) to
drive the air damper to its low fire position.

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Sequence of Operation

To assure that the system is in low fire position prior to ignition, the low fire switch (LFS) must be closed to com­plete the “low fire proving circuit.” The sequence will stop and hold until the modulating damper motor (MDM)
has returned to the low fire position and the contacts of the low fire switch (LFS) are closed. Once the low fire
switch is closed, the sequence is allowed to continue.

NOTE: The ignition trial cannot be started if flame or a flame simulating condition is sensed during the pre-purge
period. A safety shutdown will occur if flame is sensed at this time.

4.3.2 — Ignition Cycle

The ignition transformer (IT) and gas pilot valve (GPV) are energized from the appropriate pilot ignition terminal.

NOTE: An oil-fired burner may be equipped with an oil pilot rather than a gas pilot. The ignition sequence of both is
identical.

The pilot flame must be established and proven by the flame detector (FD) within a 10 second period in order for
the ignition cycle to continue. If for any reason this does not happen, the system will shut down and safety lockout
will occur.

NOTE: Depending upon the requirements of the regulatory body, insurer, or fuel being burned, either the 10 or 15
second pilot ignition terminal may be used. Both provide the same function but differ in time interval allowed for
proving main flame ignition. Refer to the boiler wiring diagram.

With a proven pilot, the main fuel valve(s) (OV or MGV) is energized and the main fuel valve light (FVL) in the
panel is lighted. The main flame is ignited and the trial period for proving the main flame begins. It lasts 10 seconds
for light oil and natural gas, and 15 seconds for heavy oil. At the end of the proving period, if the flame detector
still detects main flame, the ignition transformer and pilot valve are de-energized and pilot flame is extinguished.

NOTE: If the main flame does not light, or stay lit, the fuel valve will close. The safety switch will trip to lock out the
control. Refer to flame loss sequence (see Section 4.4) for description of action.

Warning

!

The cause for loss of flame or any other unusual condition should be investigated and corrected before attempting to
restart. Failure to follow these instructions could result in serious injury or death.

4.3.3 — Run Cycle

With main flame established, the program relay releases the modulating damper motor (MDM) from its low fire
position to control by either the manual flame control (MFC) or the modulating control (MC), depending upon the
position of the manual-automatic switch (MAS). This allows operation in ranges above low fire.

With the manual-automatic switch (MAS) set at automatic, subsequent modulated firing will be at the command of
the modulating control (MC), which governs the position of the modulating damper motor (MDM). The air

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4.4 — Flame Loss Sequence

damper and fuel valves are actuated by the motor through a linkage and cam assembly to provide modulated firing
rates.

NOTE: Normal operation of the burner should be with the switch in the manual-automatic position and under the
direction of the modulating control. The manual position is provided for initial adjustment of the burner over the
entire firing range. When a shutdown occurs while operating in the manual position at other than low fire, the damper
will not be in a closed position, thus allowing more air than desired to flow through the boiler. Excess air flow subjects
the pressure vessel metal and refractory to undesirable conditions. The effectiveness of nozzle purging is lost on a No.
6 oil burner.

The burner starting cycle is now complete. The LDL and FVL lights on the panel remain lit. Demand firing contin­ues as required by load conditions.

4.3.4 — Burner Shutdown: Post Purge

The burner will fire until steam pressure or water temperature in excess of demand is generated. With modulated
firing, the modulating damper motor (MDM) should return to the low fire position before the operating limit con­trol (OLC) opens. When the limit control circuit is opened, the following sequence occurs:

1. The main fuel valve circuit is de-energized, causing the main fuel valve (MGV or OV) to close.

2. The flame is extinguished.

3. The control panel lights (LDL and FVL) are turned off.

4. The blower motor continues to run to force air through the boiler for the post purge period.

5. On a No. 6 oil burner, the air purge valve (APV) is powered from the blower motor start circuit via the contacts

of the air purge relay (APR) to provide an air purge of the oil nozzle. The damper motor returns to the low fire
position if it is not already in that position.

6. The blower motor start circuit is de-energized at the end of the post purge cycle and the shutdown cycle is com-

plete.

The program relay is now ready for subsequent recycling, and when steam pressure or water temperature drops to
close the contacts of the operating control, the burner again goes through its normal starting and operating cycle.

4.4 — Flame Loss Sequence

The program relay will recycle automatically each time the operating control closes, or after a power failure. It will
lockout following a safety shutdown caused by failure to ignite the pilot, or the main flame, or by loss of flame.
Lockout will also occur if flame or flame simulating condition occurs during the pre-purge period.

The control will prevent startup or ignition if limit circuit controls or fuel valve interlocks are open. The control
will lock out upon any abnormal condition affecting air supervisory controls wired in the running interlock circuit.

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Sequence of Operation

Caution

!

The lockout switch must be manually reset following a safety shutdown. The cause for loss of flame or any unusual
condition should be investigated and corrected before attempting to restart. Failure to follow these instructions could
cause damage to the equipment.

4.4.1 — No Pilot Flame

The pilot flame must be ignited and proven within a 10-second period after the ignition cycle begins. If not proven
within this period, the main fuel valve circuit will not be powered and the fuel valve(s) will not be energized. The
ignition circuit is immediately de-energized and the pilot valve closes, the reset switch lights and lockout occurs
immediately.

The blower motor will continue to operate. The flame failure light and the alarm bell (optional) are energized 10
seconds later.

The blower motor will be de-energized. The lockout switch must be manually reset before operation can be
resumed.

4.4.2 — Pilot But No Main Flame

When the pilot flame is proven, the main fuel valve circuit is energized. Depending upon the length of the trial-for­ignition period, the pilot flame will be extinguished 10 or 15 seconds later. The flame detecting circuit will respond
to de-energize the main fuel valve circuit within 2 to 4 seconds to stop the flow of fuel. The reset switch lights and
lockout occurs immediately. The blower motor will continue to operate.

The flame failure light and alarm bell (optional) are energized 10 seconds later.

The blower motor will be de-energized. The lockout switch must be manually reset before operation can be
resumed. (Refer to the previous caution notice.)

4.4.3 — Loss of Flame

If a flame outage occurs during normal operation and/or the flame is no longer sensed by the detector, the flame
relay will trip within 2 to 4 seconds to de-energize the fuel valve circuit and shut off the fuel flow. The reset switch
lights and lockout occurs immediately. The blower motor continues operation. The flame failure light and alarm
bell (optional) are energized 10 seconds later.

The blower motor will be de-energized. The lockout switch must be manually reset before operation can be
resumed.

If the burner will not start, or upon a safety lockout, the troubleshooting section in the operating manual and the
technical bulletin should be referred to for assistance in pinpointing problems that may not be readily apparent.

The program relay has the capability to self-diagnose and to display a code or message that indicates the failure
condition. Refer to the control bulletin for specifics and suggested remedies. Familiarity with the program relay and
other controls in the system can be obtained by studying the contents of the manual and bulletin.

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4.4 — Flame Loss Sequence

Knowledge of the system and its controls will make troubleshooting much easier. Costly down time or delays can
be prevented by systematic checks of the actual operation against the normal sequence to determine the stage at
which performance deviates from normal. Following a routine may possibly eliminate overlooking an obvious con­dition, often one that is relatively simple to correct.

Remember, a safety device, for the most part, is doing its job when it shuts down or refuses to operate. NEVER
attempt to circumvent any of the safety features.

Preventive maintenance and scheduled inspection of all components should be followed. Periodic checking of the
relay is recommended to see that a safety lockout will occur under conditions of failure to ignite either pilot or main
flame, or from loss of flame.

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Sequence of Operation

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CHAPTER 5 S tarting and Operating

Instructions

5.1 — Preparation for Startup: All Fuels

The instructions in Chapter 5 are all based upon installation being complete and all electrical, fuel, water, and vent
stack connections are made.

The operator should be familiar with the burner, boiler, and all controls and components. To quickly locate and
identify the various controls and components mentioned the following paragraphs, refer to the illustrations and the
contents of Chapters 1, 2, and 3. Instructions for adjusting major components are given in Chapter 6 — Chapter 6
should be reviewed prior to firing. The wiring diagram should also be thoroughly reviewed, along with the firing
sequence outlined in Chapter 4.

Warning

!

Be sure the starting instructions are read completely and thoroughly understood before attempting to operate the
boiler, rather than performing each operation as it is read for the first time. Failure to follow these instructions could
result in serious injury or death.

Verify supply of fuel and proper voltage. Check for blown fuses, open circuit breakers, dropped out overloads, etc.
Check reset of all starters and controls having manual reset features. Check the lockout switch on the programmer
and reset if necessary.

The boiler should be filled with water to the proper operating level using water of ambient temperature. Be sure
that treated feedwater is available. In heating applications, the entire system should be filled and vented. Refer to
Chapter 3 for water requirements. On a steam boiler, open the test valve to vent air displaced during filling. Leave
the test valve open until the escape of steam is noted after the burner is operating.

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Starting and Operating Instructions

Warning

!

Prior to firing a boiler, be sure that discharge piping from safety valves or relief valves, and discharge piping from all
blowdown and drain valves, is piped to a SAFE point of discharge, so that emission of hot water or steam cannot pos­sibly cause injury. Failure to do so could result in serious injury or death.

Check all linkage for full and free movement of the damper and metering valves and cams. The check can be done
by loosening the linkage at the damper motor connecting arm and manipulating the linkage by hand.

Check for rotation of all motors by momentarily closing the motor starter or relay. The blower impeller rotation is
counterclockwise when viewed from the front of the boiler. The air pump rotation is clockwise when viewed from
its drive end. When operating a standard 78” boiler, the fan motor and air pump should rotate counterclockwise.

Before operating the boiler feed pump or oil supply pump, be sure all valves in the line are open or properly posi­tioned.

For safety reasons, perform a final pre-startup inspection, especially checking for any loose or incomplete piping or
wiring or any other situations that might present a hazard.

NOTE: The pressure vessel support legs are welded to mounting skids in front and secured by bolts at the rear of the
pressure vessel. The bolts are tightened for shipment. When the boiler is installed, and prior to initial firing, the bolts
securing the rear legs to the skid must be loosened to allow for expansion and contraction caused by differences in
temperature between pressure vessel and skids and to avoid damage to the equipment.

5.2 — Control Settings: Steam and Hot Water

See Chapter 6 for adjustment instructions for the following controls:

5.2.1 — Operating Limit Control

Inspect the operating limit control for proper setting.

• The operating limit pressure control of a steam boiler should be set slightly above the highest desired steam

pressure, but at least 10% lower than the setting of the safety valve.

• The operating limit temperature control on a hot water boiler should be set slightly above the highest desired

water temperature and within the limits of the pressure vessel.

5.2.2 — High Limit Control

Inspect the high limit control for proper setting.

• On a high pressure steam boiler, the control should be set approximately 10 psig above the operating limit pres-

sure control setting, if feasible, or midway between the operating limit pressure and the safety valve setting. The
setting on a low pressure steam boiler may be 2 or 3 psig above the operating limit setting, but must not exceed
the safety valve setting.

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5.3 — Gas Pilot

• On a hot water boiler, the high limit temperature control should be 5º to 10º F above the operating limit tem-

perature control setting but within the limits of the design pressure of the pressure vessel.

5.2.3 — Modulating Control

Inspect the modulating control for proper setting. The control must be set and adjusted so that the modulating
motor returns to low fire position before the operating limit control opens. It is further desirable to have its low
point setting somewhat below the cut-in setting of the limit control so that the burner operates in low fire position
for a brief period on each start rather than immediately driving to a high fire position.

NOTE: The settings of all the above controls may require some readjustment after the boiler is started and running
for a short period. The scale settings on the controls are relatively accurate, but are principally for use as guides. Final
adjustment should be based on and agree with the reading of the steam pressure gauge or the water temperature ther­mometer.

5.2.4 — Low-Water Cutoff and Pump Control

Inspect the low-water cutoff and pump control as well as the auxiliary low-water cutoff (if equipped with this
optional device). Check for freedom of float movement. Float movement can be verified by observing the level of
water in the gauge glass when the water supply has been cut off either by the stopping of the feed pump or by the
closing of a valve, and the restarting of the pump or opening of the valve when water is drained from the pressure
vessel. The importance of proper functioning of low-water controls cannot be over-emphasized. Be sure that the
control and the piping are level.

The CB Level Master is the standard low water cutoff device on CB high pressure steam boilers. See CB manual
750-281 for complete operation, maintenance, and parts information.

5.2.5 — Additional Considerations

The settings of controls relating to fuel, either oil or gas, are covered in subsequent sections.

In the event the boiler is equipped with optional control devices not listed here, be certain to ascertain that their
settings are correct. If additional information is required, see your local Cleaver-Brooks authorized representative.

On initial startup or whenever the boiler is placed into operation from a “cold” start, the manual-automatic selector
switch should be set at “manual” and the manual flame control set at “close.” After the boiler is in operation and
thoroughly warmed, the selector switch should be turned to “automatic,” so that the burner firing rate may be con­trolled by the modulating control in accordance with load demands.

Close all power entrance switches (supplied by others).

5.3 — Gas Pilot

The gas pilot should be checked for satisfactory performance prior to initial firing. Follow the pilot flame adjust­ment instructions given in Chapter 6.

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Starting and Operating Instructions

On initial starting attempts, several efforts might be required to fully bleed the pilot line. While checking pilot
adjustment, observe whether the pilot flame is extinguished promptly when the burner switch is opened. A linger­ing flame indicates a leaking gas pilot valve, which is a condition requiring correction before proceeding.

5.4 — Atomizing Air

The supply and pressure of the atomizing air on an oil-fired burner should be checked. Before starting, inspect the
oil pump lube oil level. Add oil if necessary to bring the level to the midpoint or slightly higher in the sight glass.
Use SAE 20 detergent oil of a grade mentioned in Chapter 8 and fill in accordance with instructions given there.

FIGURE 5-1. Atomizing Air Compr e ssor

Check the oil level of the air intake strainer. When operating a standard 78” boiler, make certain that the V-velt
which drives the air pump is in place and has proper tension.

To verify air flow and pressure, place the burner run/test switch on the program relay to the “test” position. If the
burner is a combination fuel burner, be sure that the gas/oil selector switch is set to “oil.” Turn the burner switch
on. The burner will cycle to the low fire pre-purge position and stop there.

FIGURE 5-2. Atomizing Air Pressure Gauge

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5.5 — Firing Preparations for No. 2 Oil (Series 100 - 200)

Observe the reading on the air pressure gauge. With no oil flow, the pressure should be a minimum of 7 psi.

If there is no pressure, determine the cause and correct it before proceeding. Check for obstructions in the air inlet
line, incorrect rotation (air pump rotation is clockwise), or a loose oil nozzle or other leaks. If the pressure is much
higher without any oil flow, check for obstruction in the discharge line or at the oil nozzle.

The air pressure will increase when an oil flow exists. At low firing rate, the air pressure may rise to 12 psi or more.

NOTE: The air pressure should not exceed 35 psi at high fire. Greater air pressure causes excessive wear of the air
pump., increases lube oil usage, and can overload the motor, thus causing damage to the equipment.

NOTE: Abnormally high pressure indicated on the nozzle air pressure gauge is an indication that the burner nozzle
has become clogged. In the event of clogging check the nozzle and clean as necessary.

After air flow has been verified, turn the burner switch off and return the run/test switch to the “run” position.

5.5 — Firing Preparations for No. 2 Oil (Series 100 - 200)

Prior to initial firing, oil flow and pressure should be established and verified. Atomizing air pressure should also be
established as outlined in Section 5.4. The schematic flow diagram (see Chapter 2) indicates the flow of fuel and
atomizing air.

If the burner is a combination fuel model, be certain that the main gas shutoff cock is closed and set the gas/oil
selector switch to “oil.” Insert the burner drawer gun into its most forward position and latch it in place.

5.5.1 — Oil Flow

1. Open all valves in the oil suction and oil return lines.

2. If the oil supply tank is located above the level of the pump and flow to the pump is by gravity, then it will usu-

ally be necessary to vent the suction line to allow oil to fill the line. Venting the suction line can generally be
accomplished by cracking a union fitting, or by opening the cap of the oil strainer using care to prevent spillage
of oil. Tighten the fitting or the cap as soon as oil flow appears.

If the oil supply tank is below the level of the oil pump, it is MANDATORY that the suction line to the pump
be completely filled with oil prior to starting the pump to avoid the possibility of damage to the pump gears.
Non-lubricating fluids such as kerosene should not be used for priming.

3. Prior to priming the suction line and the initial start, check to make certain that all plugs, connections, etc., have

been securely tightened to prevent leaks.

4. If the fuel oil supply originates from a pressurized loop, it is assumed that the pressure of the loop will be at a

minimum of 75 psi. Under these conditions, the relief valve at the terminal block should be adjusted to the point
where it becomes inoperative (or removed and openings plugged). To render inoperative, turn the adjusting
screw in as far as possible.

5. A standard equipped boiler has a selector switch incorporated in the oil pump motor starter. Momentarily ener-

gize the starter to check for proper pump rotation. With the rotation verified, operate the pump to determine
that oil circulation exists.

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Starting and Operating Instructions

6. Observe the regulated oil pressure gauge for indication that flow is established. If no pressure shows on the

gauge after a few moments, stop the oil pump and re-prime.

If the supply tank is lower than the pump, it is possible that the initial priming of the suction line, followed by
operation of the pump, will not establish oil flow. This might be caused by obstruction in the suction line, exces­sive lift, inadequate priming, suction line leaks, etc.

If oil flow is not readily established, avoid prolonged operation of the pump to minimize risk of damage to
internal parts of the pump.

NOTE: If oil flow is not established after a second or third priming attempt, a full investigation is required to deter­mine the cause.

7. A vacuum (or a compound pressure-vacuum) gauge should be installed at the suction port of the pump and its

reading observed and recorded for future guidance. If a vacuum condition exists, the reading will reveal the
tightness of the system. It is advisable to maintain the vacuum reading at less than 10” Hg.. A vacuum in excess
of 10” Hg. may allow oil to vaporize, causing cavitation, loss of prime, and unstable firing condition.

FIGURE 5-3. No.2 Fuel Oil Control

5.5.2 — Oil Pressure

1. Oil supply pressure is regulated by adjusting the pressure relief valve at the oil terminal block. A pressure gauge

should be installed in the terminal block and the relief valve adjusted to obtain a minimum reading of 75 psi
when the burner is firing at maximum rate.

2. When oil is supplied from a pressurized loop to a multiple boiler installation, the relief valve in the loop should

be properly adjusted to provide this reading. In this circumstance, the relief valve at the terminal block should
be adjusted to the point when it will be inoperative (or removed and openings plugged). To render inoperative,
turn the adjusting screw in as far as possible.

3. Adjustment may also be required to the regulator on the fuel oil controller. The pressure regulating valve is

equipped with tubing that directs and adds atomizing air pressure to the adjustable spring pressure. Since the air
pump is not running at this time, only tentative adjustment can be made. Without the air supply, adjust the fuel
oil pressure regulator so that the oil burner gauge registers approximately 35 psi.

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5.6 — Firing Preparation for No. 6 Oil (Series 400 - 600)

4. The pressure gauge will indicate a higher reading when the flame is present and will increase as the firing rate

increases. After the burner is firing and when the air pump is running, final adjustment can be made at the fuel
oil controller.

5. Final regulation of oil flow to the nozzle can be done later, if necessary, by adjusting the metering cam screws as

outlined in Chapter 6.

5.5.3 — Starting

When all the conditions covered in Sections 5.1 through 5.5 are assured, the burner is ready for firing. Refer to Sec­tion 5.8 for further starting and operating information.

5.6 — Firing Preparation for No. 6 Oil (Series 400 - 600)

Prior to initial firing, oil flow, pressure, and temperature should be established and verified. Atomizing air pressure
should also be established as outlined in Section 5.4. The schematic flow diagram (see Chapter 2) indicates the flow
of fuel and atomizing air.

NOTE: Prior to firing, attach combustion analysis instruments and monitor consistently throughout the startup
sequence. Refer to the adjustment procedures in Chapter 6.

If the boiler is a combination fuel model, be certain that the main gas shutoff cock is closed and set the gas/oil
selector switch to “oil.” Insert the burner drawer gun into its most forward position and latch it in place.

5.6.1 — Oil Flow

1. Open all valves in the oil suction and oil return lines.

2. Open the bypass valve on the fuel oil controller until oil flow is established. Normally, the orifice valve is left in

a closed position. however, on cold starts, it may be opened for brief periods to aid in establishing oil flow. The
bypass and orifice valves must be returned to the closed positions as soon as oil flow is established as indicated
by a reading on the oil supply pressure gauge. Do not at temp to set pressures while valves are open.

FIGURE 5-4. No. 6 Fuel Oil Control

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Starting and Operating Instructions

3. Momentarily energize the fuel oil pump starter to check for proper pump rotation. With the rotation verified,

prime the suction line strainer with oil and turn the fuel oil pump switch to the “ON” position.

4. Check the oil supply pressure gauge for indication that oil flow is established. If no pressure shows on the gauge

after a few moments, stop the oil pump and re-prime. Heavy oil in the storage tank must be at a temperature to
produce an oil viscosity that will allow the oil to flow through the oil pump and suction line. If oil flow is not
established after several attempts, the conditions preventing oil flow must be determined and corrected to avoid
damage to the pump’s internal mechanism.

5. A vacuum gauge should be installed in the oil suction line and its reading observed and recorded for future

guidance.

5.6.2 — Oil Pressure

Oil pressure is regulated at several points. The first is at the relief valve at the oil heater. The relief valve should be
set so that at maximum firing rate a minimum reading of 75 psi is obtained on the oil supply pressure gauge.

The other pressure adjustments are to the regulators on the fuel oil controller. Both the pressure regulating and the
back pressure relief valves are equipped with tubing that directs and adds atomizing air pressure to the adjustable
spring pressure. Since the air pump is not running at this time, only tentative adjustments can be made. Without the
air supply, adjust the fuel oil pressure regulator so that the burner oil gauge registers approximately 35 psi. Adjust
the back pressure relief valve so that its gauge reads about 10 psi less than the burner gauge.

After the burner is firing, further adjustments can be made, if necessary, to the valves.

The pressure gauges will indicate higher readings when a flame is present. The pressure will increase as the firing
rate increases. The pressure reading on the two gauges on the controller will, despite the fluctuation, retain a nearly
constant difference of 10 psi.

Final regulation of oil flow to the nozzle can be done, if necessary, by adjusting the metering cam screws as outlined
in Chapter 6.

5.6.3 — Oil Temperature

Suggested oil pressures at high fire operation:

Oil Supply at the Fuel Oil Controller 75 psi

Oil Burner Pressure Gauge 30 - 45 psi

Caution

!

Before turning on the electric oil heater switch, be certain that the heater shell is filled with fuel oil and the flow is
established. Failure to follow these instructions could result in equipment damage.

1. After determining that the heater shell is filled and that fuel oil circulation exists, turn the oil heater switch to

“on.”

2. Adjust the electric oil heater thermostat to maintain oil temperature at approximately 200º F.

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5.7 — Firing Preparations for Gas (Series 200-400-700)

The electric heater on burners equipped for No. 6 fuel oil is sized so that it is capable of supplying heated oil at
a rate no greater than that required for low fire operation and is primarily supplied for convenience on cold
starts. Heating coils utilizing either steam or hot water are supplied to provide sufficient heat so that higher rates
of firing can be accomplished once steam pressure or hot water is available. In normal operation, the thermostat
governing the electric heating element is kept at a lower setting than the thermostat governing admission of
steam to the heater, or of hot water circulation, so that heating is not performed electrically except when steam
or hot water is not available.

3. Set the steam thermostat or the hot water thermostat to maintain an oil temperature of 220º - 230º F. The elec-

tric heater will be turned off automatically as soon as steam or hot water provides heat.

NOTE: The temperatures listed are tentative. The composition of the fuel oil in a given grade can vary, necessitating a
higher or lower preheating temperature. The viscosity of the oil at the nozzle should be less than 300 SSU and prefera­bly less than 150 SSU. The actual temperature of the oil at the burner should be determined by flame appearance and
good combustion based on a stack analysis. Review this chapter for additional information.

4. Close the manual bypass valve after the temperature rise on the fuel oil controller thermometer is noted. Be cer-

tain that hot oil is moving through the controller. The orifice gate valve must also be closed. If the temperature
drops, open the orifice gate valve until a rise is noted, then close it.

5. Once the correct setting of the heater thermostats has been established, set the low oil temperature switch at the

point approximately 30º F lower than the normal burning temperature. If the system is equipped with a high oil
temperature switch, it should be set to open at 20º to 30º F higher than normal burning temperature.

NOTE: The maximum oil temperature allowed in the system is 250º F.

5.6.4 — Starting

When all the conditions covered in Sections 5.1, 5.2, 5.3, and 5.4 are assured, the burner is ready for firing. Refer to
Section 5.8 for further starting and operating information.

5.7 — Firing Preparations for Gas (Series 200-400-700)

1. Prior to initial starting, check the linkage attached to the gas butterfly valve to assure that movement is free from

binding.

2. Verify the presence and availability of gas. On a new installation, representatives of the gas utility should be pres-

ent when gas first flows into the system to supervise purging of the new gas line, unless they have already done
so.

3. Determine that the pilot is operating properly, as outlined in Section 5.3.

4. Determine that sufficient pressure exists at the entrance to the gas train by installing a test gauge downstream of

the regulator.

5. The gas pressure regulator must be adjusted to the proper pressure level. Since the regulator is generally sup-

plied by others, adjustment should proceed according to instructions supplied by its manufacturer.

It is necessary for the operator to know the burner requirements in gas quantity and pressure. The information
can generally be found on the Dimension Diagram (DD) supplied by Cleaver-Brooks for the specific installa­tion. Should the information not be readily available, consult the Cleaver-Brooks Service Department, and be

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Starting and Operating Instructions

prepared to provide the correct boiler serial number. Chapter 6 contains additional information along with stan­dard gas flow and pressure requirements.

6. If the burner is a combination fuel model, set the gas/oil switch to “gas.” Withdraw the oil burner gun and latch

it in its rearward (OUT) position.

FIGURE 5-5. Latch Oil Burner Gun “IN” and “OUT” Positions

7. On initial startup, it is recommended that the main gas shutoff cock remains closed until the programmer has

cycled through pre-purge and pilot sequences. When the fuel light on the control panel comes on, observe the
action of the motorized gas valve stem to determine that it opens when energized.

8. As soon as it is confirmed, turn the burner switch “OFF” and let the programmer finish its cycle.

9. Check that the gas valve has closed.

10. Again, turn the burner “ON.”

11. When the fuel valve light flows, slowly open the main gas cock. Main flame should ignite unless there is air pres-

ent in the line.

12. If the flame is not established within about 5 seconds, turn the burner switch “OFF” and allow the programmer

to recycle normally for a new lighting trial. Several efforts may be necessary to “bleed” air from the line.

Warning

!

Do not repeat unsuccessful lighting attempts without rechecking the burner and pilot adjustments. Failure to follow
these instructions could result in serious injury or death.

NOTE: The burner and control system is designed to provide a “pre-purge” period of fan operation prior to establish­ing ignition spark and pilot flame. Do not attempt to alter the system or to take any action that might circumvent the
feature.

13. Once the main flame is established, turn the burner switch to the “OFF” position and observe that the flame is

extinguished promptly. The flame may continue to burn for a second or two after normal shutdown due to the
gas remaining downstream from the fuel valve.

14. If the flame continues to burn for a longer period or during blower motor spindown, it could indicate a main

gas valve leak. Immediately turn the burner switch off and close the main gas cock.

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5.8 — IFGR Setup

15. Investigate and correct the cause of the valve leakage before relighting the burner.

NOTE: The main gas valve should provide a tight seal, provided nothing prevents tight closure. Foreign material may
be present in either the new or renovated gas lines unless adequate care is taken in cleaning and purging.

When the conditions covered in Section 5.7 and in Sections 5.1, 5.2, and 5.3 are assured, the burner is ready for fir­ing. Refer to Section 5.8 for further starting and operating information.

5.8 — IFGR Setup

NOTE: Initial IFGR linkage settings and adjustments must be established by a Cleaver-Brooks authorized representa­tive. Setup of the LE option requires simultaneous consideration of air-to-fuel ratios and NO

accomplished with proper combustion emissions monitoring equipment with NO

, O2, CO, and smoke spot measur-

X

ing capability.

levels. This can only be

X

It is recommended that the final “installed” settings be recorded for future reference. The settings should be
marked on the linkage as well.

Normally, once the system has been set and adjusted, the settings should not be changed unless conditions (includ­ing boiler settings) change. In that case, it will be necessary to contact your local Cleaver-Brooks authorized repre­sentative for assistance.

After the IFGR system is initially set up, it will start up with the boiler as an integrated boiler system. After shut­down periods in which maintenance and/or adjustments have been performed on the fuel cams, fuel and air link­ages, or IFGR control linkages, the recommended approach to startup is as follows:

1. Set all boiler components to their initial settings as discussed in the appropriate chapters of this manual.

2. Check fan impeller and motor rotation. Correct rotation is counterclockwise when viewed from the front of the

boiler.

3. Verify that all the IFGR components are set to the settings recorded on the Startup Report (as noted by the

Cleaver-Brooks authorized representative during original set up). Be sure that all linkages are secure.

4. Start and warm the boiler as described in this manual.

5. Adjust the boiler components as described in this manual to achieve proper boiler operation.

Refer to Chapter 8 for instructions on cassette removal and installation.

NOTE: The IFGR system can be equipped with either a single or dual linkage arm, depending on the number of fuels
used and the NO

have a dual arm, depending on the options purchased.

levels desired. All single-fueled boilers have a single drive arm. Dual-fueled boilers may or may not

X

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FIGURE 5-6. Jackshaft Linkage Settings

Starting and Operating Instructions

FIGURE 5-7. Overtravel Linkage Settings

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5.9 — Startup, Operating and Shutdown: All Fuels

FIGURE 5-8. Flange Collar and Damper Settings (Top View)

5.9 — Startup, Operating and Shutdown: All Fuels

Depending upon the fuel being burned, the applicable previous sections in this chapter should be reviewed for pre­liminary instructions.

1. When firing with oil, be certain that the burner gun is in its most forward position and latched in place. When

firing with gas, the burner gun should be properly withdrawn and latched in place. The fuel selector switch
should be, accordingly, set to either oil or gas.

2. Set the manual-automatic switch to “manual” and turn the manual flame control to “close.”

3. Turn the burner switch to “ON.” The load demand light should glow. The low-water level light should remain

out, indicating a safe water level in the boiler. The programmer is now sequencing. See Chapter 4 for sequence
details.

NOTE: On an initial starting attempt, several efforts might be required to accomplish “bleeding” of fuel lines, main,
or pilot. If ignition does not then occur, do not repeat unsuccessful attempts without rechecking the burner and pilot
adjustment.

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Starting and Operating Instructions

4. On ignition failure, the flame failure light will glow and the blower will purge the boiler of unburned fuel vapors

before stopping. After ignition failure, wait a few moments before resetting the lockout switch.

Warning

!

Do not re-light the pilot or attempt to start the main burner, either oil or gas, if the combustion chamber is hot and/or
if gas or oil vapor combustion gasses are present in the furnace or flue passages. Failure to follow these instructions
could result in serious injury or death.

Warning

!

The burner and control system is designed to provide a “pre-purge” period of fan operation prior to establishing igni­tion spark and pilot flame. Do not attempt to alter the system or take any action that might circumvent the “pre-purge”
feature. Failure to follow these instructions could result in serious injury or death.

5. After main flame ignition, the burner should be set on manual control at its low-fire setting (that is, with manual

flame control at “close”) until the boiler is properly warmed. Close the steam header.

In the case of a steam boiler, CLOSE the test valve when the steam begins to appear.

A hot water boiler must have a continuous flow of system water through the vessel during the warmup period.
The entire water content of the system and boiler must be warmed prior to increasing fuel input.

6. If the flame at low-fire provides insufficient heat to reach normal operating pressure or temperature after 30

minutes, gradually increase the firing rate by turning the manual flame control in one point increments to no
higher than the third cam screw. Operate at the increased fuel input rate for a period of time until an increase is
noted in pressure or temperature.

7. After the boiler is thoroughly warmed, turn the manual flame control to high-fire. At this point a combustion

analysis should be made, with instruments, and fuel flow regulated as required. Refer to the adjustment proce­dures in Chapter 6. After making the high-fire adjustment, manually decrease the firing rate, stopping at each
cam screw to analyze combustion gasses, and adjust as required.

To properly perform the testing and adjusting, it is necessary that the burner be allowed to fire at a maximum rate
long enough to achieve desired results.

5.9.1 — Operating

Normal operation of the burner should be with the switch in the automatic position and under the direction of the
modulating control. The manual position is provided for initial adjustment of the burner over the entire firing
range. When a shutdown occurs while operating in the manual position at other than low-fire, the damper will not
be in a closed position, thus allowing more air than desired to flow through the boiler.

NOTE: The hot flame to cool air cycling subjects the pressure vessel metal and refractory to undesirable conditions.

With the switch set at “automatic,” the burner will operate on a modulating basis according to the load demand.

The burner will continue to operate with modulated firing until the operating limit pressure or temperature is
reached, unless:

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5.10 — Control Operational Test and Checks

• The burner is manually turned “off.”

• The low-water condition is detected by low-water level control.

• The electrical or fuel supply is interrupted.

• The combustion air pressure or atomizing air pressure drops below minimum level.

NOTE: There can be other reasons for shutdown, such as motor overload, flame outages, tripped circuit breakers,
blown fuses, or through other interlock devices in the circuitry.

When the burner is shut down normally, by either the operating limit control or by manually switching the burner
off, the load demand light no longer glows.

Shutdown through conditions causing safety or interlock controls to open will actuate the flame failure light (and
alarm if so equipped) and the load demand light will remain lit. The cause of this type of shutdown will have to be
located, investigated, and corrected before operation can be resumed. Refer to the “troubleshooting” section in
Chapter 7.

5.9.2 — Shutdown

When the operating limit control setting is reached to open the circuit or if the burner switch is turned “off.” the
following sequence occurs.

The fuel valve is de-energized and the flame is extinguished. The timer begins operation and the blower motor con­tinues running to force air through the furnace in the post-purge period.

At the end of the programmed post-purge period, the blower motor is turned off. The air pump motor of an oil­fired burner is also turned off. The timer has returned to its original starting position and stops. The unit is ready to
restart.

Warning

!

It is advisable to check for tight shut-off of fuel valves. Despite precautions and strainers, foreign material in either new
or renovated fuel lines may lodge under a valve seat and prevent tight closure. The situation is especially true in new
installations. Promptly correct any conditions causing leakage. Failure to follow these instructions could result in seri­ous injury or death.

5.10 — Control Operational Test and Checks

Proper operation of the various controls should be verified and tested when the boiler is initially placed into ser­vice, or whenever a control is replaced. Periodic checks should be made thereafter in accordance with a planned
maintenance program.

The operating limit control may be checked by allowing steam pressure or water temperature to increase until the
burner shuts down. Depending upon the load, it may be necessary to manually increase the firing rate to raise steam
pressure to the burner shut off point. If the load is heavy, the header valve can be closed or throttled until the pres-

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Starting and Operating Instructions

sure increases. Observe the steam gauge to check the cutoff pressure as the operating limit control shuts the burner
down. Slowly open the header valve to release steam pressure and check the cut-in setting as the burner restarts.
Check the modulating control for the desired operating pressure range. See Chapter 6 for instructions on the
adjustment of controls.

The water temperature on a hot water boiler that may be operating at less than full load may be raised by manually
increasing the firing rate until the burner shuts down through the action of the operating limit control. Observe the
thermometer to verify the desired settings at the point of cut-out and again when the burner restarts. Return the
manual automatic switch to “automatic” and check the modulating control for the desired temperature range. See
Chapter 6 for instructions on the adjustment of the controls.

Check the proper operation and setting of the low-water cutoff (and pump operating control, if used).

Proper operation of the flame failure device should be checked at startup and at least once a week thereafter. Refer
to Chapter 8 for information on flame safety checks. Check the program relay’s annunciation for any system failure.
Observe the promptness of ignition of the pilot flame and the main flame.

Check for tight shutoff of all fuel valves. Despite precautions and strainers, foreign material may lodge under a
valve seat and prevent tight closure. Promptly correct any conditions that cause leakage.

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CHAPTER 6 Adjustment Pr ocedur es

6.1 — Overview

Each Cleaver-Brooks boiler is tested for correct operation before shipment from the factory. However, variable
conditions such as burning characteristics of the fuel and operating load conditions may require further adjustment
after installation to assure maximum operating efficiency and economy.

A combustion efficiency analysis made during the initial startup will help to determine what additional adjustments
are required in a particular installation.

Prior to placing the boiler into service, a complete inspection should be made of all controls, connecting piping,
wiring, and all fastenings such as nuts, bolts, and setscrews to be sure that no damage has occurred, or that adjust­ments have not changed during shipment and installation.

The adjustment procedures in Chapter 6 apply to standard components furnished on steam or hot water boilers
fired with gas and/or the various grades of oil.

6.1.1 — High Turndown Burner

In order to reduce stress on boiler components and to improve boiler operating efficiency, burners have been
designed for enhanced fuel turndown capabilities. A High Turndown Burner (HTB) is installed on boilers equipped
to fire light oil (Series 100), or gas (Series 700), or both (Series 200). Air and fuel inlets, the diffuser, and the air
damper control linkage have been modified for these burners.

NOTE: Observe that proper air damper linkage and fuel metering adjustment procedures are followed for standard
(Series 400 or 600) or HTB (Series 100, 200, or 700) burners to avoid damage to the equipment. The burner series is
identified on the boiler data plate affixed to the front head of the boiler.

Contact your local Cleaver-Brooks authorized representative or the Cleaver-Brooks Service Department for recom­mendations covering special controls that are not included in Chapter 6.

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Adjustment Procedures

6.2 — Linkage: Modulating Motor and Air Damper

The linkage consists of various arms, connecting rods, and swivel ball joints that transmit motion form the modu­lating motor to the metering cam(s), rotary air damper, and gas butterfly valve.

NOTE: On combination gas and oil boilers, the gas butterfly valve might not be used. Also on combination gas and
oil boilers, the oil metering valve might not be used.

When properly adjusted, a coordinated movement of the damper and metering cams within the limits of the mod­ulating motor travel is attained to provide proper fuel-air ratios through the firing range.

In linkage adjustments there are several important factors that must serve as guides.

• The modulating motor must be able to complete its full travel range.

Caution

!

Do not restrict the full travel of the modulating motor. Failure to follow these instructions could result in equipment
damage.

• Initial adjustment should be made with the motor in full closed position, that is with the shaft on the power end

of the motor in its most counterclockwise position.

• The closer the connector is to the drive shaft, the less the arm will travel - the closer the connector is to the

driven shaft, the farther that arm will travel.

• Over-travel linkage, where used, should not be required in order to extend its spring to the fullest stretch.

With the modulating motor in the low-fire position, the arm on its shaft should be at an angle of 45º below the hor­izontal. The driven arm on the jackshaft should also be 45º below horizontal. Secure both arms and fit the connect­ing linkage rod in place between them.

Position the oil and/or gas modulating cams on the jackshaft so that the cam follower assembly is between the first
and second cam adjusting screws (under the first adjusting screw for High Turndown Burners). In this position,
fuel delivery is at low-fire rate. Tighten the set screws to secure the cams on the jackshaft.

FIGURE 6-1. Rotary Air Damper

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6.2 — Linkage: Modulating Motor and Air Damper

FIGURE 6-2. Complete Linkage Assembly: Combination Gas and Oil

The stop screw in the rotary air damper limits damper travel at both closed (low-fire) and fully opened (high-fire)
positions. The screw is provided so that it is possible to tell, even with the burner in place, whether the damper
rotor is in fully opened or closed position. Rotating the damper clockwise to the stop screw closes the damper.
Rotating the damper counterclockwise to the stop screw opens the damper. Normally, the rate of flow of air
through the damper with the rotor in low-fire position is about one-third of maximum for a standard burner or
one-sixth for a HTB.

The amount of angular movement controlling the rate of air flow is determine by the location of the ends of the
rotary air damper rod in both the jackshaft arm and the air damper arm. When the air damper is in low-fire posi­tion, the jackshaft arm should be at 45º (47-1/2º for HTB) and the rotary air damper arm should be at an angle of
approximately 60º below the horizontal. This will ensure that the angular movement of the damper starts slowly,
increasing in rate as the high fire position is approached.

Prior to initially firing a boiler it is advisable to check for free movement of the linkage. The damper motor must be
allowed to complete its full stroke and the damper must move freely from low- to high-fire position. Adjustment of
linkage connected to a gas butterfly valve is describe in Section 6.17.

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Adjustment Procedures

6.3 — Modulating Motor

The modulating motor has a 90º shaft rotation. The motor manufacturer also provides a 160º stroke model for
other applications. If a replacement is obtained from someone other than a Cleaver-Brooks Service or Parts repre­sentative, it may have an incorrect stroke. To prevent damage, determine the 90º stroke prior to installing a replace­ment.

The stroke may be determined by powering the motor and connecting terminals R-B to actually determine the
stroke as the motor drives to an open position.

FIGURE 6-3. Modulating Motor

6.4 — Modulating Motor Switches: Low-Fire and High-Fire

The modulating motor contains either one or two internal switches, depending upon application. The micro­switches are actuated by adjustable cams attached to the motor shaft.

Factory replacement motors have the cams preset. The low-fire start switch is set to make the red and yellow leads
at approximately 8º on motor closing. The high-fire purge air proving switch (located in the modulating motor) is
set to make red and blue tracer leads at approximately 60º on motor opening. Normally, the settings are left as is,
but job conditions may require readjustment. If the cams require adjustment or resetting, follow the instructions in
the manufacturer’s technical manual.

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6.5 — Burner Operating Controls: General

6.5 — Burner Operating Controls: General

NOTE: Adjustments to the boiler operating controls should be made by an authorized Cleaver-Brooks Service Tech­nician. Refer to the appropriate boiler operation and maintenance manual for specific information on boiler startup
and operation.

The standard boiler operating control package consists of three separate controls.

1. High Limit Control: Senses the hot water temperature or steam pressure. It is used as a safety limit to turn the

burner off in the event the operating limit control fails. The high limit control should be set sufficiently above
the operating limit control to avoid nuisance shutdowns.

2. Operating Limit Control: Senses temperature or pressure and automatically turns the burner on to initiate the

startup sequence when required and turns the burner off to initiate the shutdown sequence when the demand is
satisfied. The control must be set to initiate startup only at the low-fire position.

3. Modulating Control: Senses changes in the hot water temperature or steam pressure and signals the modulat-

ing motor to control the flow of fuel and air to the burner. With either steam or hot water boilers, the modulat­ing control must be set to ensure the burner is at its minimum low-fire position before the operating limit
control either starts or stops the burner.

When adjusting or setting controls, first be sure all control devices are securely mounted and level. With the tem­perature sensing control, make sure the sensing bulb is properly bottomed in its well and is secured against move­ment. Be sure the connecting tubing is not kinked.

The dial settings are generally accurate, although it is not unusual to have a slight variation between a scale setting
and an actual pressure gauge or thermometer reading. Always adjust the control setting to agree with pressure
gauge or thermometer readings. Accurate instrument readings are required. When necessary use auxiliary test
equipment to set controls.

Burner controls correctly set to match load demands will provide operational advantages and achieve the following
desirable objectives:

• The burner will be operating in low-fire position prior to shutdown.

• The burner will operate at low-fire for a brief period on each start during normal operation.

• Elimination of frequent burner on-off cycling.

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Separate and independent controls affect modulated firing and burner on-off cycling.

Adjustment Procedures

FIGURE 6-4. Firing Graph

The burner will be “on” whenever the pressure or temperature is less than point B (see Figure 6-4) and “off ”
whenever pressure or temperature is greater than point A. The distance between points A and B represents the
“on-off ” differential of the operating limit control.

In normal operation, the burner will shut down whenever the pressure or temperature rises above setting A. At that
point the switch in the operating limit control will open. As the pressure or temperature drops back to B, the oper-
ating limit control closes and the burner will restart. The modulating control will signal the modulating motor to be
in a low-fire position. If the load demands exceed the low fire input potential, the modulating control will increase
the firing rate proportionately as pressure or temperature falls toward point D. The modulating motor will stop at
any intermediate point between C and D whenever the fuel input balances the load requirement.

As the load requirement changes, the firing rate will change accordingly. Thus it is referred to as modulated firing.

Point D represents the maximum firing rate of the burner, or high-fire. In the event pressure or temperature drops
while the burner is firing at high-fire, it indicates that the load exceeds the capacity of the boiler.

The firing graph (Figure 6-4) shows that point B and point C do not coincide. Extreme load conditions could
require the points be closely matched.

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6.5 — Burner Operating Controls: General

When set as shown, with a time lag between B and C, the burner will be in a low-fire position upon a restart and
will fire at that rate for a short period of time before falling pressure or temperature requires an increase in the fir­ing rate.

NOTE: On-off cycling in excess of 8 cycles per hour will shorten the life of the combustion air motor and cause
excessive wear on switch gear and pilot electrodes.

If points B and C overlap when restart occurs, the burner would drive to a higher firing position immediately after
the main flame was proven.

NOTE: It is not recommended that the boiler controls be set so as to overlap the modulating control range and oper­ating control range.

When firing a cold boiler, it is recommended that the burner be kept at low-fire, under manual flame control, until
normal operating pressure or temperature is reached. If the burner is not under manual control on a cold start, it
will immediately move toward high-fire as soon as the program control releases the circuit that holds the burner in
low-fire. The modulating control will be calling for high-fire and the burner will move to that position as rapidly as
the damper motor can complete its travel.

NOTE: Rapid heat input can subject the pressure vessel metal and refractory to undesirable conditions.

Do not operate the boiler in excess of 90% of the safety valve relief setting. The closer the operating pressure is to
the safety valve relief pressure, the greater the possibility of valve leakage. continued leakage, however slight, will
cause erosion and necessitate early safety valve replacement. The control settings on a hot water boiler must be
within the temperature limits of the boiler.

Ideally, the boiler operating controls should be set under actual load conditions. Especially under new construction
conditions, the boiler is initially started and set to operate under less than full load requirements. As soon as possi­ble thereafter, the controls should be reset to provide maximum utilization of the modulating firing system. To
accomplish maximum utilization, and assuming that air/fuel combustion ratios have been set, make the required
adjustments to the controls to bring the boiler pressure or temperature up to meet the load requirements.

To properly set the modulating control, carefully adjust it under load conditions, until the load is maintained with
the burner firing at a steady rate. The firing rate at that point may be full high-fire or slightly less, depending upon
the relationship of the boiler size to the load.

When the modulating control is set and the burner is in full high-fire, the scale setting of the modulating pressure
control on a steam boiler will indicate the low point of the modulating range. The scale setting of the modulating
temperature control on a hot water boiler will have a reading that indicates the midpoint of the modulating range.

The operating limit control should now be adjusted and the differential established. In an installation that does not
require a very close control of steam pressure or water temperature, the adjustable differential should be set as wide
as conditions permit, since a wide setting will provide less frequent burner cycling.

The high limit control provides a safety factor to shut the burner off in the event the operating limit control should
fail. The setting of the control should be sufficiently above the operating limit control to avoid nuisance shutdowns.
The setting, however, must be within the limits of the safety valve settings and should not exceed 90% of the valve
setting. The control requires manual resetting after it shuts off the burner.

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Adjustment Procedures

In the setting of the controls, consideration must be given to the time required for a burner restart. Each start,
requires a pre-purge period, plus the fixed time required for proving the pilot and main flame. In addition, approx­imately one-half minute is required for the damper motor to travel from low to high-fire. The time lag may allow
pressure or temperature to drop below desirable limits.

6.6 — Modulating Pressure Control: Steam

Turn the adjusting screw until the indicator is opposite the low point of the desired modulating range. Modulated
firing will range between the low point and a higher point equal to the modulating range of the particular control.

• in 0 - 5 psi controls the range is 1/2 lb

• in 5 - 150 psi controls the range is 5 lbs

• in 10 - 300 psi controls the range is 12 lbs

Caution

!

To prevent burner shutdown at other than low-fire setting, adjust the modulating pressure control to modulate to low­fire BEFORE the operating limit pressure control shuts off the burner. Failure to follow these instructions could result
in damage to the equipment.

6.7 — Operating Limit Pressure Control: Steam

Set the “cut-out” (burner off) pressure on the main scale using the large adjusting screw. Set the differential on the
short scale by turning the small adjusting screw until the indicator points to the desired difference between cut-out
and cut-in pressures. The “cut-in” (burner on) pressure is the cut-out pressure minus the differential. The cut-out
pressure should not exceed 90% of the safety valve setting.

6.8 — High Limit Pressure Control: Steam

Set the “cut-out” (burner off) pressure on the main scale using the adjusting screw. The control will break a circuit
when pressure reaches this point. The setting should be sufficiently above the operating limit pressure control to
avoid shutdowns, and preferably not exceed 90% of safety valve setting. The control requires manual resetting after
tripping on a pressure increase. To reset, allow pressure to return to normal and then press the reset button.

6.9 — Modulating Temperature Control: Hot Water

Turn the knob on the front of the case until the pointer indicates the desired setpoint temperature. The desired set­point is the center point of a proportional range. The control has a 3º to 30º differential and may be adjusted to
vary the temperature range within which modulating action is desired.

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6.10 — Operating Limit Temperature Control: Hot Water

FIGURE 6-5. Hot Water Controls

With the cover off, turn the adjustment wheel until the pointer indicates the desired range.

Caution

!

To prevent burner shutdown at other than low-fire setting, adjust the modulating pressure control to modulate to low­fire BEFORE the operating limit pressure control shuts off the burner. Failure to follow these instructions could result
in damage to the equipment.

6.10 — Operating Limit Temperature Control: Hot Water

Set “cut-out” (burner off) temperature on the scale by inserting a screwdriver through the cover opening to engage
the slotted head adjusting screw. The “cut-in” (burner on) temperature is the cut-out temperature minus the differ­ential. The differential is adjusted from 5º to 30º F.

6.11 — High Limit Temperature Control: Hot Water

Set the “cut-out” (burner off) temperature on scale using the adjusting screw. The control will break the circuit and
lock out on a rise in water temperature above the setting. The setting should be sufficiently above the operating
limit temperature to avoid unnecessary shutdowns. On a 30 psig hot water boiler, the setting is not to exceed 240º
F. The control requires manual resetting after tripping on a temperature increase. To reset, allow the water temper­ature to drop below the cut-out setting less differential, and then press the manual reset button.

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Adjustment Procedures

6.12 — Low Water Cutoff Devices: Steam & Hot Water

No adjustment is required since LWCO controls are preset by the original manufacturer. However, if the water
level is not properly maintained, inspect the devices immediately and replace as required.

6.13 — Combustion Air Proving Switch

Air pressure against the diaphragm actuates the switch which, when made, completes a circuit to prove the pres­ence of combustion air. Since the pressure of the combustion air is at its minimum value when the damper is full
open, the switch should be adjusted under that situation. It should be set slightly below the minimum pressure, but
not too close to that point to cause nuisance shutdowns.

The run/test switch on the program relay should be set to TEST. Turn the burner switch on. The blower will start
(provided that all limit circuits are completed) and the programmer will remain in the low-fire (damper closed) por­tion of the pre-purge.

NOTE: On an oil fired boiler, the atomizing air proving switch (AAPS) must also be closed.

On a combination fuel fired burner, the fuel selector switch could be set at “gas” to eliminate the atomizing air proving
switch from the circuitry.

To have the modulating damper motor drive to high-fire (damper open), remove the cover from the motor and
remove the wire from terminal W.

Slowly turn down the Combustion Air Proving Switch (CAPS) adjusting screw until it breaks the circuit. Here the
programmer will lock out and must be manually reset before it can be restarted. Add a half turn or so to the adjust­ing screw to remake its circuit.

Recycle the program relay to be sure that normal operation is obtained. Replace the wire on terminal W and re­install the cover. Return the test switch to the RUN position.

6.14 — Atomizing Air Proving Switch

The air pressure against the diaphragm actuates the switch which, when closed, completes a circuit to prove the
presence of atomizing air. Since the pressure of the atomizing air is at its minimum value when there is no fuel pres­ent at the nozzle, adjustment of the switch should be done while the unit is running but not firing. The control
should be set slightly below the minimum pressure, but not too close to that point to cause nuisance shutdowns.

The control adjustment may be made during the pre-purge period of operation by stopping the programmer during
the pre-purge period through the use of the TEST switch. Refer to the control instruction bulletin for details.

The adjustment screw of the atomizing air proving switch can then be adjusted until it breaks the circuit. Here, the
programmer will lock out and must be manually reset before it can be restarted. Turn the adjusting screw up a half
turn or so to remake the circuit.

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6.15 — Gas Pilot Flame Adjustment

Since the adjustment of the air switch may be made either during the damper closed or damper open position of
pre-purge, it is also possible to make the adjustment with the relay stopped in the damper open position in a similar
manner to the adjustment of the combustion air proving switch described in Section 6.13.

After making the adjustment, recycle the control to be sure that normal operation is obtained. The TEST switch
must be set to RUN position.

6.15 — Gas Pilot Flame Adjustment

The size of the gas pilot flame is regulated by adjusting the gas flow through the pilot gas regulator and the pilot
adjusting cock on the front of the burner. The flame must be sufficient to ignite the main flame and to be seen by
the flame detector. But an extremely large flame is not required. An overly rich flame can cause sooting or carbon
buildup on the flame detector. Too small a flame can cause ignition problems.

Although it is possible to visibly adjust the size of the pilot flame, it is preferable to obtain a microamp or voltage
reading of the flame signal.

The correct voltage or microamp readings can be found in the information supplied with the flame safeguard sys­tem.

The program relay used may be of the type that provides message information that includes a constant flame signal
of DC voltage. In this case a separate DC voltmeter is not required.

6.15.1 — Measure and Adjust Pilot

1. When making a pilot adjustment, turn the manual-automatic switch to “manual” and the manual flame control

to “close.”

2. Open both the cutoff cock and the pilot adjusting cock. The main gas cock should remain closed.

The regulator in the pilot line, if provided, is to reduce the gas pressure to suit the pilot’s requirement of
between 5” to 10” WC. Regulator adjustment is not critical, however, with a lower pressure the final adjustment
of the pilot flame with adjusting cock is less sensitive.

3. Connect the micro-ammeter.

4. Turn the burner switch on. Let the burner go through the normal pre-purge cycle. When the ignition trial

period is signaled, set the test switch to the TEST position to stop the sequence.

5. If the pilot flame is not established within 10 seconds, turn off the burner switch. Repeat the lighting attempt.

NOTE: On an initial starting attempt, portions of the fuel lines may be empty and require “bleeding” time. It is better
to accomplish this with repeated short lightning trial periods with intervening purge periods than to risk prolonged fuel
introduction. If the pilot does not light after several attempts, check all components of the pilot system.

6. When the pilot flame is established, and with the pilot adjusting cock wide open, remove the flame detector

from the burner plate. The pilot flame can then be observed through this opening.

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Adjustment Procedures

Warning

!

Wear a protective shield or suitable glasses and keep eyes sufficiently away from the sight tube opening to avoid serious
personal injury. Never remove the flame detector while the main burner is firing.

When checking the pilot flame, be aware the electrode is energized.

Failure to follow these instructions could result in serious injury or death.

7. To make the final adjustment, slowly close the gas pilot adjusting cock until the flame can no longer be seen

through the sight tube. Then slowly open the cock until a flame providing full sight tube coverage is observed.

The adjustment must be accomplished within the time limit of the safety switch or approximately 30 seconds
after the detector is removed. If the control shuts down, manually reset it. Replace the detector and repeat the
process from step 6.

8. When a suitable flame is obtained, replace the detector. Observe the reading on the micro-ammeter. The read-

ing should be between 2-1/4 and 5 microamps when using a lead sulfide detector and a standard amplifier. See
the flame signal table in the manufacturer's bulletin for values of other combinations.

The flame signal indicated on the annunciator type relay should not be less than 10 Vdc, and may be as high as
20 Vdc or greater.

The reading must be steady. If the reading fluctuates, recheck the adjustment. Be sure that the flame detector is
properly seated and that the lens is clean.

9. Return the test switch to the RUN position.

10. If main flame has not been previously established, proceed to do so in accordance with proper instructions.

11. The reading of the main flame signal should also be checked. Observe the flame signal for pilot alone, pilot and

main burner flame together, and the main burner flame at high, low, and intermediate firing rate positions.
Readings should be steady and in the range indicated in Step 8. If there are any deviations, refer to the trouble­shooting section in the technical bulletin.

6.16 — Gas Pressure and Flow Information

Because of variables in both the properties of gas and the supply system, it will be necessary to regulate the pres­sure of the gas to a level that produces a steady, dependable flame that yields highest combustion efficiency at rated
performance yet prevents overfiring. Once the optimum pressure has been established, it should be recorded and
periodic checks made to verify that the regulator is holding the pressure at this level. Occasional modification in
fuel composition or pressure by the supplier may, at times, require readjustment to return the burner to peak effi­ciency. Since the gas pressure regulator itself is usually furnished by others, detailed adjustment instructions and
adjusting procedures recommended by the manufacturer should be followed.

6.16.1 — Pressure

The gas supplied must provide not only the quantity of gas demanded by the unit, but must also be at a pressure
high enough to overcome the pressure-loss due to the frictional resistance imposed by the burner system and the
control valves.

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