Following is an explanation of the abbreviations, acronyms,
and symbols used in this manual.
It is essential to read and understand the following safety
precautions before attempting to operate the equipment.
Failure to follow these precautions may result in damage to
equipment, serious personal injury, or death. A complete
understanding of this manual is required before attempting to
start-up, operate or maintain the equipment. The equipment
should be operated only by personnel who have a working
knowledge and understanding of the equipment.
The following symbols are used throughout this manual:
!
WARNING
DANGER
This symbol indicates a potentially
hazardous situation which, if not
avoided, could result in serious
personal injury, or death.
!
CAUTION
DANGER
This symbol indicates a potentially hazardous situation which, if not avoided, could
result in damage to the equipment.
Note: This symbol indicates information
that is vital to the operation of this
equipment.
AC Alternating Current
AR Automatic Reset
ASME American Society of Mechanical Engineers
ASTM American Society of Testing and Materials
BHP Boiler Horsepower
BTU British Thermal Unit
°C Degrees Celsius
CFH Cubic Feet per Hour
Cu Ft Cubic Feet
DC Direct Current
°F Degrees Fahrenheit
FM Factory Mutual
FSFlame Safeguard
ftFeet
GPM Gallons per Minute
Hd Head
HT Height
HTB High Turndown Burner
HZ He rt z
OInches of Water
In H
2
IRI Industrial Risk Insurance
Lb Pound
LWCO Low-Water Cut-Off
MMillion
MFD Micro-Farad
MR Manual Reset
NECNational Electric Code
No. Number
pH Measure of the degree of acid or base of a
solution
P/N Part Number
PPM Parts Per Million
PR Program Relay
psi Pounds Per Square Inch
SAE Society of Automotive Engineers
scfh Standard Cubic Feet per Hour
T Tempera ture
TC Temperature Control
TI Temperature Gauge
MODEL FLX
PACKAGED BOILER
Operation, Service, and Parts Manual
1,500,000 to 12,000,000 Btu/hr
Fuel: Light Oil, Gas or Combination
Cleaver-Brooks 2001
Please direct purchase orders for replacement manuals to your local Cleaver-Brooks authorized representative
Manual Part No. 750-177 R4
Revised 6/2001
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 OPERATE, SERVICE, OR REPAIR THIS EQUIPMENT UNLESS THEY FULLY
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.
The services of a qualified water treating company or a water consultant to recommend the proper boiler water treating practices
are essential.
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.
E. Hot Water Controls (All Fuels) . . . . . . . . . . . . . . . . 1-4
A. General
The information in this manual applies directly to CleaverBrooks FLX Model boilers in sizes ranging from 1,500,000
to 12,000,000 Btu/hr input.
Fuel Series
700- Gas
100-No.2 0il
!
CAUTION
DANGER
The care taken in placing the boiler into initial
service is vital to continuous, reliable operation.
If the boiler is to be used for temporary heat (for
example in new construction), properly treated
water must be used. Failure to do so can be
detrimental to the boiler.
200 - Combination Gas & No.2 Oil
Design Pressure
160 psig hot water
15 psig steam
150 psig steam
750-1771-1
Figure 1-1: FLX Cut Away
Chapter 1GENERAL DESCRIPTION
B. The Boiler
The Cleaver-Brooks Model FLX is a five-pass steel boiler
with flexible watertubes formed and arranged so as to direct
the flow of combustion gases through the boiler. The pressure
vessel conforms to Section I or IV of the ASME code. The
pressure vessel consists of the formed tubes, the external
downcomer, and the top and bottom drums to which they
connect. The heated area of the pressure vessel is contained
within a gas tight insulated casing that is composed of
removable formed steel panels.
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.
The Model FLX boiler is a packaged watertube boiler of
welded steel construction and consists of a pressure vessel,
burner, burner controls, forced draft fan, damper, refractory,
and appropriate boiler trim.
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
DANGER
Waterside care is of prime importance. For
specific information or assistance with your
water treatment requirements, contact your
Cleaver-Brooks service and parts represen
tative. 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 down-time, 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.
-
Hot water is commonly used in heating applications with the
boiler supplying water to the system at 180 °F to 220 °F. The
operating pressure for hot water heating systems usually is
30 psig to 125 psig.
Steam boilers are designed for low and high pressure applications. Low pressure boilers are limited to 15 psig design
pressure, and are typically used for heating applications.
High pressure boilers are limited to 150 psig design pressure,
and are typically used for process steam applications.
Steam and hot water boilers are defined according to design
pressure and operating pressure. Design pressure is the max
imum pressure used in the design of the boiler for the purpose of calculating the minimum permissible thickness 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 pres
sure relieving valve(s) to prevent their frequent opening during normal operation.
-
C. Construction
Steam boilers designed for 15 psig and hot water boilers
designed for 250°F at 160 psi or less are constructed in
accordance with Section IV, Heating Boilers, of ASME Code.
Steam boilers designed for 150 psig are constructed in
accordance with Section I, Power Boilers, of the ASME
Code.
D. Steam Controls (All Fuels)
-
1.Operating Limit Pressure Control (Figures 1-2 and 1-3):
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.
2.High Limit Pressure Control (Figure 1-2 and 1-3):
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
equipped with a manual reset.
1-2750-177
GENERAL DESCRIPTIONChapter 1
3.Modulating Limit Pressure Control (Figure 1-2 and 1-3):
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.”
4.Low Water Cutoff and Pump Control (Figure 1-2, 1-4
and 1-5): 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; also causes 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.
!
CAUTION
DANGER
Determine that the main and auxiliary low
water cutoffs and pump control are level af
ter installation and throughout the equipment’s operating life. Failure to follow these
instructions could result in equipment dam
age.
5.Water Column Assembly (Figure 1-2): Houses the lowwater cutoff and pump control and includes the water
gauge glass, gauge glass shutoff cocks.
6.Water Column Drain Valve (Figure 1-2): 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.
7.Gauge Glass Drain Valve (Figure 1-2): Provided to flush
the gauge glass.
8.Safety Valve(s) (Figure 1-6 and 1-8): Prevent 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 valves 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
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
12
1. HIGHLIMITPRESSURECONTROL
2. OPERATINGLIMITPRESSURECONTROL
3. MODULATINGPRESSURECONTROL
Figure 1-3: Steam Controls
3
draw the mounting bolts down evenly. Do not install or
remove side outlet valves by using a pipe or wrench in
the outlet.
!
WARNING
DANGER
Only properly certified 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
personal injury or death
E. Hot Water Controls (All Fuels)
Figure 1-4: Low Water Cut Off (LWCO)
1.Water Temperature Gauge (Figure 1-7): Indicates the
boiler internal water pressure.
2.Water Pressure Gauge (Figure 1-7): Indicates the internal
pressure of the boiler.
3.Operating Limit Temperature Control (Figure 1-7):
Breaks a circuit to stop burner operation on a rise of
boiler temperature at a selected setting. It is adjusted to
Figure 1-5: Low Water Cut Off Pump Control
(Cutaway)
1-4750-177
Figure 1-6: Safety Valve Cutaway
GENERAL DESCRIPTIONChapter 1
stop or start the burner at a preselected operating
temperature.
4.High Limit Temperature Control (Figure 1-7): 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 is equipped
with a manual reset.
5.Modulating Temperature Control (Figure 1-7): 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.”
6.Low Water Cutoff (Figure 1-7): Breaks the circuit to stop
burner operation if the water level in the boiler drops
below safe operating point, activating low-water light
and optional alarm bell if burner is so equipped.
7.Auxiliary Low Water Cutoff (Not Shown) (Optional):
Breaks the circuit to stop burner operation if the water
level in the boiler drops below the master low-water
cutoff point.
8.Safety Valve(s) (Figure 1-6 and 1-8): Prevent 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 valves 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
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
WATER
PRESSURE
GAUGE
WATER
TEMPERATURE
GAUGE
LOW WATER CUTOFF PROBE
23
1
1. High Limit Temperature Control
2. Operating Limit Temperature Control
3. Modulating Temperature Control
4. Low Water Cutoff Control
4
750-1771-5
Figure 1-7: Hot Water Controls
Chapter 1GENERAL DESCRIPTION
SUPPORT FROM BUILDING
DISCHARGE OPENING
MUST BE EQUAL TO OR LARGER THAN
INLET
SAFETY VALVE
NOTICE: BACK-PRESSURE OF STEAM EXHAUST SYSTEM MUST BE LESS THAN 6% OF SAFETY VALVE SETTING.
WATER LEVEL
CONSTRUCTION
CAUTION - VENT
PIPE
MUST NOT
TOUCH DRIP
PAN EXTENSION
DRIP ELL DRAIN
TO STEAM
VENT
VENT PIPE
DRIP PAN
EXTENSION
AND ELBOW
OPEN DRAIN
TO WASTE
BOILER SHELL
Figure 1-8: Recommended Piping For Steam
Relief Valve (Not furnished by Cleaver-Brooks)
DRIP PAN
1 1/2”
MIN.
DRIP PAN
DRAIN
remove side outlet valves by using a pipe or wrench in
the outlet.
!
WARNING
DANGER
Only properly certified personnel such as
the relief valve manufacturer’s certified
representative can adjust or repair the
boiler relief valves. Failure to follow these
instructions could result in serious
personal injury or death.
D. CONTROLS AND COMPONENTS . . . . . . . . . . . . 2
The burner and all boiler related equipment must be installed
in accordance with applicable local, state or provincial
installation requirements including the National Electrical
Code (NEC) and associated insurance underwriters. Where
applicable, the Canadian Gas Association (CGA) B149 and
Canadian Standards Association (CSA) B140 codes shall
prevail.
Note: If the boiler is not equipped with a
ProFire burner, Please refer to the specific
Operation and Maintenance manual for the
burner supplied.
Note: The main power disconnect for this
equipment must be conspicuously labeled
and placed within
system, and/or equipped with lockout
provisions.
Note: This manual must be readily available
to all operators, and maintained in legible
condition.
sight of the operating
A. GENERAL
The information provided in this manual covers ProFire
burners installed on Flextube boilers.
The information in this chapter provides guidance for startup,
testing, and adjustment of the Cleaver-Brooks ProFire burner.
Personnel working on or operating the burner or related
equipment must become familiar with all the procedures and
information contained in this manual prior to initial startup,
operation and/or adjustment of the burner.
This chapter applies exclusively to the Cleaver-Brooks
ProFire Burner, and focuses specifically on tasks related to
adjustment of linkages and controls for efficient combustion
and safe operation, pre-startup checkout and initial burner
startup.
B. BURNER
The ProFire Burner is designed to operate with natural gas or
light oil at input rates from 1.5 to 12.0 MMBtu/hr. The burner
can be configured to burn natural gas only, oil only, or as a
natural gas or oil burner.
The burner includes all components and controls required for
automatic modulating burner operation, and is also capable of
operation over the full range under manual control.
The model number completely identifies its configuration.
This information is located on the unit parts list, shipped with
the burner. The model number components are as follows:
GP - W - X - Y - Z
Where:
GP designates the burner orientation, blower housing
down.
W designates the fuel; gas, oil, or combination (700, 100,
or 200, respectively).
• 100-Light Oil
• 200- Light Oil and Natural Gas
• 700- Natural Gas
X designates the frame size of the burner (1, 2, 3 & 4).
Y designates burner capacity (MMBtu/hr).
Z designates the insurance underwriter.
For Example:
GP - 700 - 2 - 3.5 - IRI
750-1772-1
2-1
Chapter 2ProFire Burner Operation and Control
MODEL NO.150200250300350400450500550600700800900100011001200
indicates a blower housing “down” unit that burns only
natural gas; it is made of size-two components, and is rated
D
for 3.5 MMBtu/hr fuel input at high fire and is configured to
meet IRI (Industrial Risk Insurers) standards.
ABC
EFG
C. RECOMMENDED FUELS AND
VENTILATION
ProFire burners are designed to burn either natural gas or
light oil (#2), as defined by ASTM D396 - 1978 specification.
!
WARNING
DANGER
This burner is designed to burn only those
fuels shown on the burner data plate.
Burning fuels not specified on the data plate
could cause damage to the equipment, or
can result in serious personal injury or
death.
Note: Structural enclosures for this
equipment must be configured to allow
ample flow of combustion and ventilation
air. See Table 2-1 for combustion air volume
requirements.
D. CONTROLS AND COMPONENTS
The burner can be equipped with special operating controls,
various types of flame safeguard systems, and/or a system to
minimize NOx emissions. The wiring and dimension
diagrams and construction reference list (available with the
burner) confirm the specific features and equipment included.
Refer to Figures 2-1 and 2-2 for component locations. The
A. FLAMEFAILURELIGHT
B. LOADDEMANDLIGHT
C. BURNERSWITCH
D. MANUALFLAMECONTROL
E. MANUAL-AUTOSWITCH
F. FUELVALVELIGHT
G. LOWWATERLIGHT
8
Figure 2-1: Control Cabinet
following list describes components and basic functions of
the burner.
1.Electrical Control Cabinet (Figure 2-1): The control
cabinet houses many of the electrical control
components and the flame safeguard. The operator
control switches and indicator lights are located on the
face of the control cabinet door. The following controls
and indicators are provided:
• Flame Failure Light: Illuminates (red) 20 seconds after the flame is extinguished. When this
happens, the system automatically shuts down;
manual reset of the flame safeguard is required.
2-2750-177
• Load Demand Light: Illuminates (white) when
ProFire Burner Operation and ControlChapter 2
the boiler operating controls indicate a demand
for hot water or steam.
• Burner Switch: Activates or deactivates the operating cycle of the flame safeguard control.
• Manual Flame Control: When in Manual Mode,
it provides manual adjustment of the burner fir
A
-
B
ing rate between low-fire and high-fire operation.
• Manual-Auto Switch: Allows the operator to
override the automatic boiler controls for manual
firing rate adjustment.
• Fuel Valve Light: Illuminates (green) when the
selected fuel valve is energized.
A. FLAMESAFEGUARD
B. FUELSELECTIONSWITCH
• Low Water Light: Illuminates (red) when the
boiler low-water cutoff control is activated.
2.Flame Safeguard (Figure 2-2): The flame safeguard
controls the operating sequences of the combustion
system (prepurge, pilot, firing, and shutdown). The
control also monitors the flame, using a scanner which is
sensitive to specific flame frequencies. The flame
safeguard also automatically shuts down the burner
when the flame signal becomes too weak. Different types
of flame safeguard devices can be installed in the
combustion systems. Check the wiring diagram for your
burner for information on the specific unit installed on
your burner.
3.Fuel Selection Switch (Figure 2-2): Allows the operator
to select either gas or oil as the active fuel on
combination burners. (The switch is located inside the
control cabinet.)
4.Pilot Gas Train (Figure 2-3). The standard pilot gas train
consists of a manual stopcock, a gas pressure regulator,
and a solenoid-operated gas shut-off valve. The gas pilot
valve assembly controls a relatively small flow rate of
natural gas to operate the gas-electric pilot.
5.Blast Tube (Figure 2-3). The blast tube functions as a
duct for combustion air, and houses the fuel nozzle(s),
gas pilot assembly, diffuser, and air baffle assemblies.
Figure 2-2: Control Cabinet (Open)
A
B
F
C
A. PILOT GAS TRAIN
B. BLAST TUBE
C. BLOWER HOUSING
D. COMBUSTION AIR FAN MOTOR
E. IGNITION TRANSFORMER
F. COMBUSTION AIR PROVING SWITCH
Figure 2-3: ProFire Burner (Left Side)
E
D
6.Blower Housing (Figure 2-3). The blower housing
encloses the impeller. The fan drive motor is mounted
directly to the blower housing.
7.Combustion Air Fan Motor (Figure 2-3). The electric
motor drives the combustion air fan and the oil pump (if
so equipped).
8.Ignition Transformer (Figure 2-3). The ignition
transformer produces the high voltage required for spark
generation by the pilot electrode(s).
9.Combustion Air Proving Switch (Figure 2-3). The
combustion air proving switch provides confirmation to
the flame safeguard that the combustion air fan is
750-1772-3
Figure 2-4: Impeller
Chapter 2ProFire Burner Operation and Control
providing air flow. The fuel supply valves will not open
if this switch does not sense adequate air pressure.
10. Impeller (Figure 2-4). The impeller is designed with
backwards-inclined vanes. It is located inside the blower
housing, and is driven by the combustion air fan motor.
The impeller provides combustion air to the burner
assembly. Removing the impeller requires the use of the
impeller puller, part number 943-388 (Figure 2-8)
11. Gas Butterfly Valve (Figure 2-5). The gas butterfly valve
regulates the flow rate of natural gas into the burner. The
gas butterfly valve is connected, by linkage and a jack
shaft, to the modulating motor, which provides the rotary
motion to open and close the valve.
12. Valve Linkage (Figure 2-5). The valve linkage transfers
the modulating motion from the main air shutter shaft to
the fuel metering valve shafts. The linkage provides a
means of adjustment to maintain the correct fuel-to-air
ratio over the entire burner operating range, high fire to
low fire.
13. Oil Metering Valve (Figure 2-5). The oil metering valve
regulates the flow rate of oil into the burner. The oil
metering valve is connected by linkage and a jack shaft
to the modulating motor, which provides the rotary
motion to open and close the valve.
14. Oil Pump (Figure 2-5). The oil pump provided for oil
burning is coupled to an extension of the combustion air
fan shaft.
15. Modulating Motor (Figure 2-5). The modulating motor is
coupled to the jack shaft that operates the main air shutter
and the fuel valve linkages. The modulating motor
produces the torque and rotary positioning required for
firing rate control.
20. Airbox (Figure 2-6). The airbox is attached to the inlet side of
the fan housing. It serves as the inlet and flow regulating
valve for combustion air, and houses the combustion air
control shutters.
21. Main Air Shutter Shaft (Figure 2-6). The main air shutter
modulates the combustion air between low fire and high fire
conditions. The shaft connects the modulating motor to the
main air shutter and to the fuel valve linkage assemblies.
G
A
F
B
D
C
E
A. GAS BUTTERFLY VALVE
B. VALVE LINKAGE
C. OIL METERING VALVE
D. OIL PUMP
E. MODULATING MOTOR
F. OIL SOLENOID VALVES
G. REAR CAP
Figure 2-5: Oil And Gas Piping To Burner
16. Oil Solenoid Valves (Figure 2-5). The oil solenoid
valves are in series and downstream of the oil metering
valve in the supply line to the oil burner assembly. Two
valves are provided. These valves are simultaneously
energized to open and release fuel oil to the burner. The
valves close to stop combustion when oil is the fuel.
17. Rear Cap (Figure 2-5). The rear cap contains the locking
setscrew for adjustment of the diffuser relative to the air
D
baffle, and also the flame scanner for the flame
safeguard. The rear cap must be removed to enable
removal of the oil gun assembly.
C
B
18. Low-Fire Shutter (Figure 2-6). The low-fire shutter
provides a means to set the correct combustion air flow
A
rate for low-fire operation. The handle indicates relative
shutter position.
19. High-Fire Shutter (Figure 2-6). The high-fire shutter
provides a means to set the correct combustion air flow
rate for high-fire operation. The handle indicates relative
A. LOW-FIRE SHUTTER
B. HIGH-FIRE SHUTTER
C. AIRBOX
D. MAIN AIR SHUTTER SHAFT
shutter position.
Figure 2-6: Airbox and Shutters
2-4750-177
ProFire Burner Operation and ControlChapter 2
ITEM
ACCOMPLISHED
BY
REMARKS
Daily
Gauges, Monitors,
OperatorMake visual inspection and record readings in log.
and Indicators
Instrument and
OperatorMake visual check against recommended specifications.
Equipment Settings
Low-water Fuel Cut-
OperatorRefer to instructions.
off And Alarm
Weekly
Low-water Fuel Cut-
OperatorRefer to instructions.
off And Alarm
Firing Rate Control OperatorVerify factory settings.
IgniterOperatorMake visual inspection. Check flame signal strength if meter-fitted (see
“Combustion safety controls”).
Pilot and Main Fuel
Valves
OperatorOpen limit switch. Make audible and visual check. Check valve position
indicators, and check fuel meters
Flame Failure
Controls
Flame Signal
Strength Controls
OperatorClose manual fuel supply for (1) pilot, (2) main fuel cock and/or
valve(s). Check safety shutdown timing. Record in log.
OperatorIf flame signal meter installed, read and log for both pilot and main
flames. Notify service if readings are very high, very low, or fluctuating.
Refer to instructions.
Monthly
Low Fan Pressure,
OperatorManually adjust until switch opens.
Interlock
High & Low Gas
OperatorRefer to instructions. Manually adjust until switch opens.
Pressure Interlocks
High & Low Oil
OperatorRefer to instructions. Manually adjust until switch opens.
Pressure Interlocks
Semi- Annually
Low-water Fuel Cutoff And Alarm
OperatorPerform a slow drain test in accordance with ASME Boiler and Pres-
sure Vessel Code Section VI.
Firing Rate Control Service Technician Verify factory settings.
Figure 2-7: Recommended Test Schedule
750-1772-5
Chapter 2ProFire Burner Operation and Control
ITEM
Inspect Burner
ACCOMPLISHED
BY
Service TechnicianRefer to instructions.
REMARKS
Components
Annually
High Limit Safety
Service TechnicianManually adjust until switch opens.
Control
Firing Rate Control Service Technician Check with combustion test.
Pilot and Main Gas
Service TechnicianPerform leakage tests. Refer to instructions
or Main Oil Fuel
Valves
Operating ControlService Technician Manually adjust until switch opens.
Fuel Valve Interlock
Service TechnicianRefer to instructions. Disconnect POC wire at valve.
Switch (POC)
Burner Position
Service TechnicianRefer to instructions. Disconnect wire at valve.
Interlock
Low Fire Start Inter-
Service TechnicianRefer to instructions.
lock
Automatic Change
Over Control (Dual
Fuel)
Pilot Turndown
Tests
Refractory Hold-In
Controls
High & Low Oil
Pressure Interlocks
Pilot Turndown
Tests
Service TechnicianUnder supervision of gas utility.
Service TechnicianRequired after any adjustments to flame scanner mount or pilot burner.
Verify annually. Refer to instructions.
Service TechnicianSee “Pilot turndown tests.”
As Required
OperatorRefer to instructions. Manually adjust until switch opens.
Service TechnicianRequired after any adjustments to flame scanner mount or pilot burner.
Verify annually. Refer to instructions.
Figure 2-7: Recommended Test Schedule (Continued)
2-6750-177
ProFire Burner Operation and ControlChapter 2
Special Tools
The Impeller puller, part number 943-388 should be used to
remove the impeller from the fan motor shaft.
To order special tools, contact your authorized Cleaver-Brooks
representative.
This chapter is devoted primarily to the waterside care of the
pressure vessel.
Proper water supply and treatment are essential to boiler life
and length of service. Proper water treatment will pay
dividends in the form of longer life, less downtime, and
prevention of costly repairs.
Hot water boilers require proper circulation. The system must
be operated as intended by its designer in order to avoid the
possibility of thermal shock with severe stress to the pressure
vessel.
B
A
C
C
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 local CleaverBrooks authorized representative.
B. WATER REQUIREMENTS
(HOT WATER BOILERS)
Air Removal
The hot water outlet (Figure 3-1) is located in the top drum of
the boiler. This location reduces the possibility of released air
(which is trapped at the top of the drum) from entering the
system. Any air (or oxygen) that may be released in the boiler
will collect at the top of the upper drum, where it will escape
through the air vent tapping (Figure 3-1). The tapping must be
properly piped to the expansion tank or a stand pipe and air
bleeder to remove gases that collect at the top of the drum.
750-1773-1
A. HOT WATER OUTLET
B. AIR BLEED TAPPING
C. PRESSURE/TEMPERATURE GAUGES
Figure 3-1: Upper Drum (Hot Water)
Continuous Flow
The system must be piped and the controls arranged so that
there will be water circulation through the boiler under all
operating conditions. Constant circulation through the boiler
eliminates the possibility of stratification within the unit.
Refer to Fig. 3-1 to determine the maximum GPM circulation
rate of boiler water in relation to full boiler output and system
temperature drop.
Table 3-1:Maximum Flow Rates for Hot Water Boilers
System Pressure
!
CAUTION
DANGER
In order to avoid damage to the equipment,
a circulating pump should be interlocked
with the burner so that the burner cannot
operate unless the circulating pump is run
ning.
It is recommended that the system circulating pumps be kept
running, even though the heat users do not require hot water.
The relief device or bypass valve will allow continuous
circulation through the boiler and will help prevent rapid
replacement of boiler water with “cold” zone water.
!
CAUTION
DANGER
The operator should determine that a circulation of water exists through the boiler before initial firing or when firing after the unit
has been drained and refilled. A reduced cir
culation of water or no water circulation
through the boiler when the burner is oper
ating may result in damage to the equipment.
-
-
-
The design of the system and the usage requirements often
will dictate the pressure exerted upon the boiler. Some
systems are pressurized with nitrogen. Caution must be
240
F
230
°
220
210
200
190
180
170
SUPPLY WATER TEMPERATURE -
160
150
10 1214
1618 2022 24
SYSTEM PRESSURE - PSI
26
28
30
Figure 3-2: Minimum System Operating Pressure
3-2750-177
Pressure Vessel CareChapter 3
exercised to make sure that the proper relationship of pressure
to temperature exists within the boiler so that all of its internal
surfaces are fully wetted at all times. It is for this reason that
the internal boiler pressure, as indicated on the water pressure
gauge, must be held to the level shown in Figure 3-3.
It is advisable to install a thermometer in the return line to
indicate return water temperature. With the return water
temperature and the supply water temperature to the system
known, the temperature differential will be established.
Knowing the flow rate, the operator easily can detect any
excessive load condition and take appropriate corrective
action.
Pressure Drop
There will be a pressure drop of less than 4 psi through all
standardly equipped Cleaver-Brooks boilers operating in any
system that has more than the 20°F temperature drop. This
drop will vary with boiler size and circulation rate. For
specific information, refer to table 3-1, Minimum Flow Rates
for Hot Water Boilers.
Minimum Boiler Outlet Water Temperature
The minimum recommended operating boiler outlet water
temperature is 150°F. When water temperatures lower than
150°F are used, the combustion gases are reduced in
temperature to a point where the water vapor in the gases
condenses. A result of condensation is that fireside corrosion
occurs in the boiler and breeching. The condensation problem
is more severe on a unit that operates intermittently or is
oversized for the actual load. This is not a matter that can be
controlled by boiler design, since an efficient boiler extracts
all the possible heat from the combustion gases.
Multiple Boiler Installations
When multiple boilers of equal or unequal size are installed,
care must be taken to ensure proportional flow through the
boilers. Proportional flow can best be accomplished by use of
balancing cocks and gauges in the supply line from each
boiler. If balancing cocks or orifice plates are used, a
significant pressure drop (for example, 3-5 psi) must be taken
across the balancing device to accomplish proportional flow.
Variations in water temperature and firing rates will result if
care is not taken to ensure proportional flow through the
boilers. In extreme cases, differences in firing rates could
result in a net header water temperature below the desired
temperature.
C. WATER REQUIREMENTS
(STEAM BOILERS)
Deaeration
The most important factor in the life of a steam pressure
vessel is the proper conditioning of the boiler feed water.
Corrosive gasses, such as oxygen and carbon dioxide, must
be removed from the feed water in order to prevent
degradation of the pressure vessel. For this reason CleaverBrooks recommends the use of a deaeration system as an
integral part of a complete boiler installation. If
circumstances do not allow the implementation of a
deaeration system, then serious consideration should be given
to effective alternatives such as a feed water preheater
combined with a chemical oxygen scavenger. Complete
boiler water chemistry parameters are given in Table 3-3.
Note: In order to maintain a minimum outlet
water temperature of 150°F the low limit of
the Operating Temperature Control should
be set at least 10° higher.
If the operating water temperature going to the system must
be lower than 150°F, the operating boiler outlet water
temperature should still be held to a minimum of 150°F.
Mixing valves are used to reduce the supply temperature
going to the system.
Note: The minimum return water
temperature through the boiler is 120°F.
!
CAUTION
DANGER
Three-way valves and system controls
should be installed or set so that the boiler
cannot be bypassed. A reduced circulation
of water or no water circulation through the
boiler when the burner is operating may re
sult in damage to the equipment.
750-1773-3
-
Feed Water Supply
The internal dynamics of the Model FLX steam boilers
require the capability to deliver large quantities of feed water
to the boiler on demand. (Feed water inlet Figure 3-3.)
Sudden changes in firing rate or operating pressure of the
Note: Feedwater to the boiler must be at least 60 °F, for minimum performance, 212 °F is preferred.
Table 3-2: Minimum Boiler Feed Water Flow Rates (Steam Boiler)
Because of the variables involved, no one “boiler compound”
Silica150 ppm
Specific Conductance3500 µmho/cm
Total Alkalinity300 ppm as C
Total Hardness0 ppm as CaCO
aCO3
3
Oxygen (O2)7 ppb
can be considered a “cure-all”; nor is it advisable to
experiment with homemade treating methods. A sound
treatment program should include a periodic analysis of the
water in the system.
The internal or waterside surfaces of the pressure vessel
should be inspected at sufficient intervals to detect the
presence of any corrosion, pitting, contamination, or
accumulations of foreign matter. If any of these conditions
pH10
are detected, contact your local Cleaver-Brooks authorized
Representative for advice on corrective action. It is
Total Iron0.05 ppm
Oily Matter1 ppm
Table 3-3: Boiler Water Quality Limits
(Steam Boilers)
recommended that a properly sized water meter be installed
in the raw water makeup line to accurately determine the
amount of raw water admitted to the boiler. It is a false
assumption that a hot water boiler does not require water
treatment. Even though a hot water unit generally operates on
a closed system and blowdown seldom is practiced, the need
boiler will initiate a “call for water” from the make-up
controller, which will require that the feed water be delivered
to the boiler in sufficient quantities to prevent a low water
remains to be alert to system water losses. Knowing the
amount of makeup water admitted to the system will aid in
maintaining proper waterside conditions.
cutoff trip. Table 3-2 lists the minimum feed water flow
requirements for the various boiler models. In addition, feed
water must be warmed to a minimum of 60°F. in order to
ensure reliable operation of the boiler. The feed water supply
should be adjusted to deliver water to the boiler at or above
these minimum rates.
A steam boiler requires periodic blowdown of the boiler and
water column (Figure 3-4). Blowdown is the removal of some
of the concentrated water from the boiler and the water level
E. BLOWDOWN
D. WATER TREATMENT
Properly treated boiler water will result in maximum
effectiveness and long trouble-free life of the pressure vessel.
Contact your local Cleaver-Brooks Representative or water
management consultant for complete information on how to
prevent damage resulting from inadequate water treatment.
The objectives of water treatment in general are to:
1.Prevent hard scale and soft sludge deposits that inhibit
heat transfer and that could lead to overheated metal and
costly downtime and repairs.
2. Eliminate corrosive gases in the supply or boiler water.
To accomplish these objectives, the boiler requires proper
water treatment before and after introduction of water into the
unit. The selection of pretreatment processes depends upon
the water source, its chemical characteristics, the amount of
makeup water needed, system operation practices, etc.
3-4750-177
Figure 3-4: Low Water Cutoff and Gauge Glass with
Blowdown Valve
Pressure Vessel CareChapter 3
control system, in order to lower the concentration of solids
in the water.
Solids are introduced to the boiler with the feedwater, even
though this water may be treated prior to use. These solids
become less soluble when the water is heated and evaporated,
and tend to accumulate on heating surfaces.
Periodic blowdown and chemical treatment are necessary to
prevent concentration of solids in the boiler water, and
attachment of these solids to waterside heating surfaces
(scaling).
Scale has a low heat transfer value and acts as an insulating
barrier on heating surfaces. A buildup of scale will result in
lower operating efficiency and, consequently, higher fuel
consumption. More importantly, scale buildup can result in
overheating of boiler metal. This can result in tube failures or
other pressure vessel damage.
!
CAUTION
DANGER
Boiler and water level control blowdown
must be performed on a regular basis to en
sure that concentrated solids are removed
from the boiler and in order to avoid damage
to the equipment.
Water column and gauge glass blowdown valves are located
on the water column assembly. The boiler blowdown
tapping(s) can be found at the bottom of the lower drum.
Most blowdown lines are provided with two valves. These
are generally a quick-opening valve nearest the boiler and a
slow-opening globe-type valve downstream. Valves will vary
depending upon pressure involved and the make or
manufacturer.
-
When initially opening the blowdown valve,
open the valve slowly to heat the discharge
piping. Failure to follow this procedure
could result in rapid expansion and damage
to the piping.
The drop of the water level in the gauge glass can be used in
determining the length of time that the blowdown valve is left
open. This is to be used as a reference only, as proper water
analysis on a regular basis will serve as an indicator of the
effectiveness of the blowdown procedures used.
Do not pump the lever action valve open
and closed when draining water during
blowdown. The hydraulic forces resulting
from this pumping action could break the
valve bodies or pipe fittings in the blow
down lines.
Blowdown valves should be closed in a specific order after
draining water for blowdown. Close the downstream (slow
opening) valve first, followed by the quick-opening valve
next to the boiler. Open the downstream valve slightly to
release the water trapped between the valves, then close the
valve again.
The water column and gauge glass should be blown down by
draining until the water in the gauge glass is clear. Open and
close the water column and gauge glass blowdown valves
slowly, allowing the water in the gauge glass to rise to a
normal level before repeating the process.
!
CAUTION
DANGER
!
CAUTION
DANGER
-
Blowdown Procedure
Blowdown is most effective when the boiler water is hot and
the burner is being fired at the lowest rate. This ensures that
the water in the boiler is being circulated, and that the solids
in the water are in suspension.
!
WARNING
DANGER
Be sure that the blowdown piping is in good
condition, the discharge vents are clear of
obstruction, and that the waste is piped to a
safe point of discharge, in order to avoid
serious personal injury or death.
If a quick-opening valve and globe-type or slow-opening
valve are installed, the quick-opening valve is normally
opened first and closed last. Control of the water released
from the boiler is accomplished with the slow-opening valve.
750-1773-5
Under no circumstances should a blowdown valve be left
open and unattended during the blowdown operation.
Frequency of Blowdown
In practice, the boiler blowdown valve(s) should be opened
periodically in accordance with a set operating schedule.
Frequency and duration of the blowdown are to be
determined by chemical analysis of boiler water and
waterside boiler condition, as observed during regular
inspections.
From an economy standpoint, frequent short blowdown is
preferred to irregularly scheduled, lengthy blowdown. This is
particularly true when the suspended solids content of the
water is high.
Chapter 3Pressure Vessel Care
F. CLEANING
Although it may be necessary to clean the system,
information in this chapter deals primarily with cleaning the
boiler under isolated conditions.
System piping connected to the boiler may contain oil,
grease, or other foreign matter. These impurities must be
removed to prevent damage to the heating surfaces of the
pressure vessel. Chemical cleaning generally is necessary in
this case and the entire system should be drained after
cleaning. Consult your local Cleaver-Brooks authorized
representative for recommended cleaning compounds and
application procedures. For information on Boilout, see
Section G, in this chapter.
Pressure Vessel
Cleaning of the waterside of the pressure vessel should be
done during the course of initial installation. The waterside of
the pressure vessel must be cleansed of grease, sludge, and
foreign material. Such deposits will shorten the life of the
pressure vessel and interfere with the efficient operation and
function of control or safety devices. In addition, deposits
might cause unnecessary and expensive rework, repairs, and
downtime.
The pressure vessel and the hot water system represent in
effect, a closed system. Although individual components of
the system may already have been cleaned, it is possible that:
G. BOILOUT
Any oil, grease, or other contamination found to be present on
waterside heating surfaces should be removed promptly by
boiling out the unit with an alkaline detergent solution.
Note: Before boiling out, the burner must be
ready for firing. Refer to the burner manual
for details. The operator must be familiar
with the boilout procedures outlined in this
section.
Cleaver-Brooks recommends the use of CB3900,(P/N 797-
1797) an alkaline, detergent-based product suitable for
cleaning all internal surfaces in heating and process boilers.
Contact your local Cleaver-Brooks authorized representative
for additional information or assistance.
If the system is to be cleaned with the boiler, consider the
additional water content of the system in determining the
UPPER HAND HOLE
1.The cleaning was not adequate.
2.An old system was partially or totally involved.
DOWNCOMER
3.Conditions may have prevented an adequate cleaning of
the piping.
Therefore, it is recommended that the entire system be
cleaned, after installation of all components is completed.
SIGHT
PORT
The pressure vessel waterside should be inspected on a
periodic basis. An inspection will reveal the true internal
conditions and will serve as a check against conditions
indicated by chemical analysis of the boiler water. An
SYSTEM
INLET
inspection should be performed 3 months after the initial start
up, then at regular 6, 9, or 12 month intervals thereafter. The
frequency of periodic inspections will depend upon the
internal conditions found, the particular installation, and the
operating conditions that the boiler is subjected to.
Figure 3-5: Rear Panel (Hot Water Boiler
If any deterioration or unusual conditions are observed,
contact your local Cleaver-Brooks authorized Representative
for recommendations.
150-
300-
400-
700-
Boiler Size
Water Capacity (US
gal.) Hot Water
Water Capacity (US
gal.) Steam - Flooded
3-6750-177
Table 3-4: Water Capacity
250
350
91106174228269
194215293464562
600
900
1000-
1200
amount of chemical required. The water capacity of CleaverBrooks FLX Boilers is listed in Table 3-4.
Boilout Procedure
1.Prepare the boiler for firing by taking the standard
precautions. Check for any situations that might present
a hazard.
2.Remove upper and lower drum handhole covers and
inspect all internal waterside surfaces. Remove debris
Pressure Vessel CareChapter 3
and wash all internal surfaces, including tubes. It may be
necessary to use a high pressure hose or a wash out lance
to flush out inaccessible areas. Reinstall the lower drum
handhole cover. (Use standard service gaskets during the
boilout procedure.)
3.The relief valve(s) must be removed before adding the
boilout solution so that neither the solution nor the
contaminants that it may carry can come in contact with
the valve(s). Use care in removing, handling, and
reinstalling these valves.
Note: For relief valve installation
information, refer to Chapter 8, Section E.
“Controls.”
4.Replace the regular gauge glass with a temporary gauge
glass that can be discarded after the cleaning (steam
boilers).
5.An overflow pipe should be connected to one of the top
boiler openings and routed to a safe point of discharge. A
relief valve tapping is usually used for this purpose. The
overflow connection to the boiler should incorporate a
tee fitting for adding cleaning solution to the boiler.
6.Fill the unit with clean water to a point just below the
access port in the upper drum. It is important that the
water used for the filling process is at a temperature of
70°F or above.
12. Throughout the entire process, each blow-down point or
valve should be blown at least once every two hours. The
total amount of water blown from all points each time
should be approximately one-half gauge glass, this
amount being equally divided among the various manual
blowdown points and continuous blowdown system.
Blow the surface and/or continuous blow-down points
first, followed by the other blowdown points lower on
the boiler. After each blowdown cycle, the water level
should be brought back to full. If the total alkalinity in
the cleaning solution falls to a level below 3000 ppm, it
may be necessary to add additional Cleaver-Brooks
3900, using a chemical pump.
13. Allow a small amount of fresh water to enter the boiler in
order to create a slight overflow that will carry off
surface impurities. Continue to boil and overflow until
the water clears.
14. It is difficult to provide specific recommendations
regarding the duration of the cleaning process. In
general, a period of 18 to 36 hours will prove sufficient
to internally clean the water-side of the boiler. The
condition of the water blown from the boiler is the best
indicator as to whether the cleaning process is complete.
15. Discontinue firing, and allow the water to cool. After
letting the water cool to 120°F or less, drain the boiler.
7.Add the recommended amount of Cleaver-Brooks 3900,
using a chemical pump. Never pump the cleaning
chemical into the boiler before adding water.
!
WARNING
DANGER
The chemicals used in this procedure are
corrosive to eyes and skin. Always refer to
the Material Safety Data Sheet to ensure that
the proper safety equipment and
precautions are present. Failure to heed this
warning could result in serious personal
injury or death.
8.Reinstall the upper handhole cover.
9.Continue to fill the boiler until it is full (indicated by flow
from the overflow connection).
10. Recheck the burner, gauge glass, pressure gauge,
feedwater supply and the position of all valves. Make
sure that all water feeding and level indicating apparatus
are in proper working condition.
11. Fire the boiler intermittently at the burners lowest fire
rate until the water reaches the boiling point. The water
should be held at this temperature for at least five hours.
Note: Do not produce pressure in the boiler.
!
WARNING
DANGER
Be sure to drain the hot water to a safe point
of discharge to avoid the possibility of
scalding, serious personal injury or death.
16. Remove the drum handhole cover, and wash the
waterside surfaces thoroughly, using a high pressure
water stream. Direct the water stream into each
individual tube. If possible, this washing should be done
from the bottom up. A wash out lance is available from
your local Cleaver-Brooks authorized representative.
17. Inspect the waterside surfaces. If they are not clean,
repeat the boilout procedures.
18. Replace the handhole covers (using new gaskets) and
reinstall the relief valve(s).
Note: Refer to Chapter 8, Section E,
“Controls” for information regarding proper
installation of relief valves.
19. If the boiler is to be put into service immediately, fill the
boiler with clean, treated water and fire the burner until
the water has been heated to at least 180°F to drive off
any dissolved gases that might otherwise corrode the
metal.
20. If the boiler is not to be put into immediate service, refer
to the section on boiler layup procedures in this chapter.
750-1773-7
Chapter 3Pressure Vessel Care
H. WASHING OUT
Depending on system integrity, feedwater quality, or
operating conditions, the water side of the boiler may need to
be washed out on occasion.
In theory, a hot water system and boiler that have been
initially cleaned, filled with clean, treated water, and with no
makeup water added, will require no further cleaning or
treatment. However, minor system leaks may allow the
admission of additional water or air into the boiler.
Introduction of raw (untreated) makeup water or air to a hot
water boiler may lead to pitting, corrosion, or formation of
sludge, sediment, or scale on the pressure vessel waterside.
The waterside condition of steam boilers can be likewise
affected by feedwater quality, load demands, operating
conditions, or blowdown practices.
The waterside of a hot water or steam boiler should be
cleaned and inspected no later than three months after the
boiler is put into service. Subsequent cleaning of waterside
surfaces should be performed as indicated through periodic
inspection.
In order to thoroughly wash out the waterside of the pressure
vessel, the handhole covers at the ends of the upper and lower
drums must be removed. The interior surfaces of the drums
should be washed with a high pressure hose. Tubes should be
cleaned by directing a high pressure stream of water into the
end of each tube, first from the bottom, and then from the top
drum.
Note: A washout lance for this purpose is
available from your local Cleaver- Brooks
authorized representative.
available. Be prepared to perform any testing required by the
inspector, including a hydrostatic test.
When shutting down a boiler, the load should be reduced
gradually and the pressure vessel should be cooled at a rate
that avoids a temperature differential that can cause harmful
stresses. Normally, all pressure should be relieved before a
vessel is drained in order to prevent uneven contraction and
temperature differential that can cause tubes to leak. Draining
the unit too quickly may cause the baking of deposits that
may be present on the heating surfaces.
Note: Check to see that system valves,
feedwater valves, all fuel valves, expansion
tank, and electrical switches are shut off
prior to opening the handholes or the
burner access door. After proper cooling
and draining of the vessel, flush out the
waterside with a high pressure water
stream. Remove any scale or deposits from
the waterside surfaces and check for
internal or external corrosion or leakage.
Fireside surfaces also should be cleaned so that metal
surfaces, welds, joints, tube fittings, and any previous repairs
can be readily checked.
!
WARNING
DANGER
To avoid the hazard of electrical shock,
which could cause serious personal injury
or death, the use of a low voltage flashlight
is recommended during an internal
inspection.
Control and water column connections on steam boilers
should be checked for accumulated deposits, and cleaned as
required.
After waterside cleaning has been completed, replace the
handhole covers, using new gaskets.
Note: Handhole cover gaskets are installed
dry; that is, without application of a sealing
compound.
I. PERIODIC INSPECTION
Insurance regulations or local codes and good maintenance
will require that the pressure vessel be inspected periodically
by an authorized inspector. Sufficient notice is generally
required to allow removal of the boiler from service and
preparation for inspection. An internal inspection may be
required before cleaning or flushing.
Have the following information available for the inspector:
boiler design, dimensions, generating capacity, operating
pressure and temperature, time in service, defects found
previously, and any repairs or modifications made to the unit.
Reference records of previous inspections also should be
3-8750-177
Fireside Inspection
Access for inspection of the firing chamber, or furnace, is
gained through the hinged burner door. Inspection of the
upper pass requires removal of the side casing panels and
second and fourth pass cover plates. Refer to Chapter 8,
Section C, “Fireside Cleaning,” for information regarding
outer and inner casing removal.
Fireside tube surfaces should be checked for corrosion or
accumulation of soot. Use a vacuum cleaner and wire brush
to remove light corrosion or soot.
Localized, heavy corrosion on fireside tube surfaces may
indicate a leaking tube or ferrule connection. If a tube or tube
ferrule leak is indicated, the source of the leakage must be
found and repaired before putting the boiler back in service.
A leak from a tube-to-drum connection may require removal
and reseating of the tube. A heavily corroded or leaking tube
must be replaced in order to assure continued reliable
operation of the boiler. Information regarding tube
replacement can be obtained from your local Cleaver-Brooks
authorized representative.
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