DriSteem SINGLE-TUBE Series, MINI-BANK Series, MULTIPLE-TUBE Series, AREA-TYPE Series Installation, Operation And Maintenance Manual

READ AND SAVE THESE INSTRUCTIONS

STEAM INJECTION

Humidifiers

Installation, Operation, and Maintenance Manual

For use with steam boilers

Safety precautions

ATTENTION INSTALLER Read this manual before installing.

Leave manual with product owner.

Where to find more information On our website: The following related documents can be

viewed, printed, or ordered from our website, www.dristeem.com

In Dri-calc Dri-calc is DriSteem’s free sizing and

selection software for calculating load, determining non-wetting distance, and selecting equipment. See Dri-calc on the www.dristeem.com Tools page. Also in Dri-calc:

A comprehensive library of Installation Guide documents, including:

• Recommended placement within a duct or air handler

• Recommended sensor placement

Or call us at 800-328-4447 Obtaining documents from our website or

from Dri-calc is the quickest way to view our literature, or we will be happy to mail literature to you.

WARNING

Indicates a hazardous situation that could result in death or serious injury if instructions are not followed.

WARNING

Attention installer

Read this manual before installing, and leave this manual with product owner. This product must be installed by qualiﬁed HVAC and electrical contractors and in compliance with local, state, federal, and governing codes. Improper installation can cause property damage, severe personal injury, or death as a result of electric shock, burns, or ﬁre.

DriSteem® technical support: 800-328-4447

Read all warnings and instructions

Read this manual before performing service or maintenance procedures on any part of the system. Failure to follow all warnings and instructions could produce the hazardous situations described, resulting in property damage, personal injury, or death.

Failure to follow the instructions in this manual can cause moisture to accumulate, which can cause bacteria and mold growth or dripping water into building spaces. Dripping water can cause property damage; bacteria and mold growth can cause illness.

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STEAM INJECTION INSTALLATION, OPERATION, AND MAINTENANCE MANUAL

Hot surfaces and hot water

Steam Injection humidiﬁers have extremely hot surfaces. Water in steam pipes and dispersion assemblies can be as hot as 212 °F (100 °C). Discharged steam is not visible. Contact with hot surfaces, discharged hot water, or air into which steam has been discharged can cause severe personal injury. To avoid severe burns, allow the system to cool before performing service or maintenance procedures on any part of the system.

Table of contents

OVERVIEW.................................................................2

Introduction .............................................2

Available models .........................................3

Basic components ........................................4

Principle of operation ......................................5

Humidifier placement ......................................6

Sensor placement ........................................9

Pressurized steam piping guidelines ..........................10

Condensate drain piping and trapping ........................14

Temperature switches .....................................16

SINGLE-TUBE HUMIDIFIER ....................................................20

Configurations .........................................20

Assembly .............................................21

Installation ............................................22

Piping notes ...........................................23

Field piping ...........................................24

MULTIPLE-TUBE HUMIDIFIER ..................................................28

Field assembly .........................................28

Installation ............................................29

Piping notes ...........................................30

Field piping ...........................................31

WARNING

Hot surface hazard

Steam humidiﬁcation systems have extremely hot surfaces.

To avoid burns, allow humidiﬁer, steam pipes, and dispersion assemblies to cool before touching any part of the system.

mc_071411_0753

ATTENTION INSTALLER

Read this manual before installing. Leave manual with product owner.

DriSteem technical support

800-328-4447

MAXI-BANK HUMIDIFIER .................................................... 36

Maxi-bank option field assembly and installation .................36

Maxi-bank option piping notes ..............................39

Maxi-bank option field piping ...............................40

Assembly and installation ..................................45

MINI-BANK HUMIDIFIER .....................................................45

Field piping ...........................................47

AREA-TYPE HUMIDIFIER ..................................................... 48

Installation ............................................48

Field piping ...........................................49

Rise, spread, and throw dimensions ..........................50

Humidifier start-up and shut-down ............................51

OPERATION ..............................................................51

Eliminating excess heat from steam jacketed humidifiers ............52

MAINTENANCE ........................................................... 54

Maintenance procedures ..................................54

Troubleshooting .........................................55

TROUBLESHOOTING........................................................ 55

REPLACEMENT PARTS ....................................................... 58

Single-tube and Multiple-tube humidifiers .......................58

Area-type humidifier .....................................60

Mini-bank humidifier .....................................61

WARRANTY .............................................................. 62

STEAM INJECTION INSTALLATION, OPERATION, AND MAINTENANCE MANUAL

OVERVIEW

Introduction

SUITABLE FOR A WIDE RANGE OF APPLICATIONS

Steam Injection humidiﬁers from DriSteem® use steam from an external source, such as an in-house boiler or a district steam system. DriSteem’s Steam Injection humidiﬁers are adaptable to virtually any size application, and a wide variety of models accommodate a broad range of steam absorption requirements.

STEAM JACKETED DISPERSION TUBE MODELS FOR DUCTS AND AIR HANDLERS

Single-tube, Mini-bank®, and Multiple-tube humidiﬁers are designed for ducts and air handlers, and capable of a wide range of guaranteed non-wetting distances.

AREA-TYPE FOR OPEN SPACES

Area-type™ Steam Injection humidiﬁers are designed for open spaces such as warehouses and manufacturing spaces that do not have a duct system. The steam discharged from the humidiﬁer is quietly dispersed by a fan without introducing water droplets into the air.

FIGURE 2-1: STEAM INJECTION HUMIDIFIERS

Each Single-tube, Mini-bank®, and Multiple-tube humidiﬁer has the same basic components: a stainless steel separator, a steam valve, and one or more jacketed dispersion tubes.

For open spaces, boiler steam can be dispersed by the fan of an Area-type model.

STEAM INJECTION INSTALLATION, OPERATION, AND MAINTENANCE MANUAL

Available models

OVERVIEW

FIGURE 3-1: STEAM INJECTION HUMIDIFIER MODELS

SINGLE-TUBE HUMIDIFIER

• Suitable for small- to medium-capacity systems,

1.5 – 525 lbs/hr (0.7 – 238 kg/h)

• Moderate to long non-wetting distance

• Pre-assembled separator/tube assembly

MINI-BANK HUMIDIFIER

• Suitable for small-capacity systems, 1.6 – 84 lbs/ hr (0.7 – 38 kg/h)

• Short to moderate non-wetting distance

• Sized for small ducts

• Pre-engineered and pre-assembled header/tube assembly, ready for mounting and hookup

MULTIPLE-TUBE HUMIDIFIER

• Suitable for small- to large-capacity systems,

6.5 – 3989 lbs/hr (2.3 – 1809 kg/h)

• Sizes to ﬁt small ducts and large air handlers

• Short to moderate non-wetting distance

• Field assembled (with interconnecting piping and header supplied by contractor)

• Maxi-bank™ option: – Pre-assembled, except when either dimension

is 98 inches (2490 mm) or more

– Includes 304 stainless steel header, with

option for 316 stainless steel

– Includes black iron piping, with options for

304 or 316 stainless steel

All Steam Injection humidiﬁers shown here, except Area-type, are available with options for applications requiring stainless steel steam components.

mc_033111_0500

AREA-TYPE HUMIDIFIER

• Suitable for medium-capacity systems, 1.8 – 286 lbs/hr (0.8 – 130 kg/h)

• Used in open spaces

• Application-dependent non-wetting distances

STEAM INJECTION INSTALLATION, OPERATION, AND MAINTENANCE MANUAL

OVERVIEW

Basic components

FIGURE 4-1: STEAM INJECTION HUMIDIFIER COMPONENTS

Section Y-Y

OM-378

Section X-X

Condensate

Steam

OM-376

Tube proﬁle with insulation

Steam-ﬁlled jacket

Steam-discharge tubelet

Dispersion tube

Optional PVDF insulation

1. Steam jacket

A chamber that jackets the inner dispersion tube with hot steam to eliminate condensation and dripping

OM-1171

Tube proﬁle without insulation

2. Steam separator

Separates steam from condensate

3. Deflector plate

Inside the steam separator, deflects condensate into a circular pattern and toward the drain

4. Multi-baffle plate

Allows only steam to rise into the upper region of the separator

5. Internal drying tube

Excludes any remaining condensate, allowing only dry steam to leave the separator

6. Steam valve

Controls the amount of steam allowed into the dispersion tube

7. Dispersion tube

Provides uniform steam dispersion across the duct width

8. Thermal-resin tubelet

Unique tubelets extend into the dispersion tube center so only the hottest, driest steam is discharged into the air. These tubelets also have an exceptional ability to trap noise generated by the valve, making DriSteem’s Steam Injection humidifiers the quietest in the industry.

9. Steam trap

Allows only condensate to pass to the condensate return system

See Figure 5-1 for a description of how these components operate together.

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STEAM INJECTION INSTALLATION, OPERATION, AND MAINTENANCE MANUAL

Principle of operation

FIGURE 5-1: STEAM INJECTION HUMIDIFIER PRINCIPLE OF OPERATION

OVERVIEW

OM-1170

About right-hand and left-hand discharge:

Imagine you are standing in the duct where the Steam Injection humidiﬁer is to be installed, with airﬂow blowing into your face:

• Specify the humidiﬁer with right-hand discharge if the separator is on your right.

• Specify the humidiﬁer with left-hand discharge if the separator is on your left.

For consistency, humidiﬁer drawings in this catalog are shown with right-hand discharge.

1. Boiler steam enters the humidifier at line pressure and flows through a chamber (jacket) surrounding an inner dispersion tube. The jacket of steam preheats the dispersion tube so that when steam enters the dispersion tube (at Step 5 below) it does not condense as it would if the tube were cold, thereby eliminating condensation and dripping.

2. After flowing through the steam jacket, steam with entrained condensate slows from entering the larger space of the separator and from hitting the perimeter deflector plate, and begins to spin and separate.

3. Separated steam rises through slots in the multi-baffle plate to the separator upper region, and enters the internal drying tube that excludes any remaining condensate, allowing only dry steam to leave the separator.

4. Separated condensate drains from the separator to the steam trap.

5. The steam valve controls the amount of steam allowed into the preheated dispersion tube. The steam valve is typically controlled in one of two ways:

• By a signal from a building automation system

• By a humidity controller connected to the steam valve

6. Steam is discharged uniformly through the tubelets into the airstream.

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STEAM INJECTION INSTALLATION, OPERATION, AND MAINTENANCE MANUAL

OVERVIEW

Humidiﬁer placement

USE THESE EXAMPLES AS GUIDELINES

Proper humidiﬁer placement is crucial for successful system operation. Usually, there is no single correct placement for a humidiﬁer. Much depends on system design and application. The following paragraphs and dispersion assembly placement examples are presented as guidelines for common situations.

FIRST, CHECK AVAILABLE ABSORPTION DISTANCE

Available absorption distance affects system choice. Dispersed steam must be absorbed into the airﬂow before it comes in contact with any duct elbows, fans, vanes, ﬁlters, or any object that can cause condensation and dripping.

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PLACING A STEAM INJECTION HUMIDIFIER IN AN AHU (SEE FIGURE 6-1)

• Location A is the best choice. Installing downstream from heating and cooling coils provides laminar ﬂow through the dispersion unit; plus, the heated air provides an environment for best absorption. Use a multiple tube dispersion unit to ensure complete absorption of steam vapor before fan entry.

• Location B is the second-best choice. In change-over periods, the cooling coil will eliminate some moisture for humidiﬁcation.

• Location C is the third-best choice. Air leaving a fan is usually very turbulent and may cause vapor to not absorb at the expected absorption distance. Allow for more absorption distance if installing downstream from a fan.

• Location D is the poorest choice. The cooler air at this location requires an increased absorption distance.

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Figure 6-1: Placing a Steam Injection humidiﬁer in an air handling unit (AHU)

Cooling coil

8' to 12' (2.4 m to 3.7 m)

ABD

3' to 5' (1 m to 1.5 m)

8' to 12' (2.4 m to 3.7 m)

Outside air

Exterior building wall

Relief air

Economizer control device

Preheat coil

Motorized air dampers

Filters

Heating coil

Duct high limit humidity control for humidiﬁer locations A, B

Airﬂow proving switch

Fan

Humidiﬁer discharges against airﬂow

Airﬂow proving switch

Return airﬂow

STEAM INJECTION INSTALLATION, OPERATION, AND MAINTENANCE MANUAL

Supply airﬂow

Duct high limit humidity control for humidiﬁer location C

DC-1081 mc_071911_1517

Humidiﬁer placement

PLACING A STEAM INJECTION HUMIDIFIER NEAR AN ELBOW (SEE FIGURE 7-1)

• Location A is the best choice. Better absorption occurs on the downstream side of an elbow than on the upstream side.

• Location B is the second-best choice. Installing upstream from an elbow can cause wetting at the turning vanes. In cases where it is structurally impossible to avoid Location B, use a multiple tube humidiﬁer to ensure complete absorption. Also, since more air ﬂows along the outside of a turn, better absorption occurs if the humidiﬁer discharges proportionately more steam in that part of the airstream.

• At both locations, discharging steam against or perpendicular to the airstream gives slightly better mixing and absorption than discharging with the airstream.

mc_071911_1518

FIGURE 7-1: PLACING A STEAM INJECTION HUMIDIFIER ASSEMBLY NEAR AN ELBOW

OVERVIEW

Airﬂow

Duct

Less airﬂow on this side of elbow

Duct high limit humidistat

Mist can collect on vanes

(2.4 m to 3.7 m)

DC-1083-1 mc_071911_1519

Airﬂow

3' to 5'

(1 m to 1.5 m)

8' to 12'

STEAM INJECTION INSTALLATION, OPERATION, AND MAINTENANCE MANUAL

OVERVIEW

Humidiﬁer placement

PLACING A STEAM INJECTION HUMIDIFIER IN A PRIMARY/SECONDARY SYSTEM (SEE FIGURE 8-1)

This type of system is commonly applied to facilities where most of the building requires one humidity level (typically to meet comfort requirements) and part of the building requires additional humidity. In Figure 8-1, the primary humidiﬁcation system is within the main air handling unit. The secondary humidiﬁcation system is located close to the point of steam discharge into the secondary area.

FIGURE 8-1: PLACING A STEAM INJECTION HUMIDIFIER IN A PRIMARY/SECONDARY SYSTEM

Exhaust airOutside air

Filter mixing box

Before humidiﬁer: 50 °F (10 °C), 47% RH

Primary humidiﬁer location

After humidiﬁer: 50 °F (10 °C), 60% RH

70 °F (21 °C), 30% RH

Secondary humidiﬁer location

50 °F (10 °C) 60% RH

VAV box

Primary area: 70 °F (21 °C), 30% RH

50 °F (10 °C), 60% RH

Secondary humidiﬁed area

Room transmitter: 65 °F (18 °C), 50% RH

STEAM INJECTION INSTALLATION, OPERATION, AND MAINTENANCE MANUAL

Sensor placement

OVERVIEW

SENSOR LOCATION IS CRITICAL

Sensor location has a signiﬁcant impact on humidiﬁer performance. See the recommendations below and Figure 9-1.

Note: DriSteem recommends that you do not interchange room and duct

humidity devices. Room humidity devices are calibrated with zero or little airﬂow, whereas duct humidity devices require air passing across them.

Recommended humidity control (transmitter/humidistat) locations:

A Ideal. Ensures the best uniform mix of dry and moist air with stable

temperature control.

B Acceptable, but room environment can affect controllability, such as

when sensor is too close to air grilles, registers, or heat radiation from room lighting.

C Acceptable. Provides uniform mixture of dry and moist air. If extended

time lag exists between humidity generation and sensing, extend sampling time.

D Acceptable (behind wall or partition) for sampling entire room if sensor

is near an air exhaust return outlet. Typical placement for sampling a critical area.

E Not acceptable. These locations might not represent actual overall

conditions in the space.

F Not acceptable. Do not place sensors near windows, door

passageways, or areas of stagnant airﬂow.

Other factors affecting humidity control

Humidity control involves more than the controller’s ability to control the system. Other factors that play an important role in overall system control are:

• Size of humidification system relative to load

• Overall system dynamics associated with moisture migration time lags

• Accuracy of humidistats and humidity transmitters and their location

• Dry bulb temperature accuracy in space or duct

• Velocities and airflow patterns in ducts and space environments

• Electrical noise or interference

mc_072011_1656

Recommended safety (airﬂow and high limit) sensor location:

G Best sensing location for high limit humidistat or humidity sensor and

airﬂow proving switch.

FIGURE 9-1: RECOMMENDED SENSOR LOCATIONS

8' to 12'

Wall or partition

(2.4 m to 3.7 m)

min.

•

Window

DC-1084

Outside air

Relief air

Damper control

Return air

•

Window

Doorway

Air handling

unit

•

High limit humidistat or high limit transmitter (set at 90% RH maximum) for VAV applications

Airﬂow switch or differential pressure switch (sail type recommended for VAV applications)

Vapor absorption has taken place

Point of vapor absorption

Humidiﬁer dispersion assembly

Turning vanes

STEAM INJECTION INSTALLATION, OPERATION, AND MAINTENANCE MANUAL

OVERVIEW

Pressurized steam piping guidelines

• Size piping in accordance with ASHRAE recommendations.

• Humidiﬁer's steam supply should be taken off top of steam main (not side or bottom) to ensure the driest steam. Main should be dripped and trapped (in accordance with ASHRAE recommendations).

• Humidiﬁer steam trap(s) must drain by gravity to return main having little or no back pressure. If condensate cannot drain by gravity, then it must be elevated to return main (see Figure 12-1 for instructions).

• If steam pressure is less than or equal to 15 psi (103.4 kPa), use ﬂoat and thermostatic (F&T) traps for the humidiﬁer.

If steam pressure is greater than 15 psi (103.4 kPa), use inverted bucket

traps for the humidiﬁer.

• If lifting condensate, use an inverted bucket trap and check valve regardless of steam pressure. See Figure 12-1 for instructions.

• Condensate from unavoidable heat loss in the distribution system must be removed promptly to eliminate water hammer and degradation of steam quality and heat transfer capability. Install drip legs at all low points and natural drainage points in the system, such as at ends of mains; bottoms of risers; and ahead of pressure regulators, control valves, isolation valves, pipe bends, and expansion joints.

On straight, horizontal runs with no natural drainage points, space drip

legs at the following intervals:

– Not exceeding 300' (91 m) when the pipe is pitched down in the

direction of the steam ﬂow

– At a maximum of 150' (46 m) when the pipe is pitched up, so that

condensate ﬂow is opposite of steam ﬂow.

These distances apply to systems where valves are opened manually to

remove air and excess condensate that forms during warm-up conditions. Reduce these distances by about half in systems that are warmed up automatically.

• Insulate piping well to avoid unnecessary heat loss.

• Pitch return lines downward in the direction of the condensate ﬂow at 1/2" per 10' (0.4%).

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STEAM INJECTION INSTALLATION, OPERATION, AND MAINTENANCE MANUAL

Pressurized steam piping guidelines

FIGURE 11-1: FIELD PIPING OVERVIEW

OVERVIEW

Take off branch lines from the top of the steam main, preferably at a 45° angle, although vertical 90° connections are acceptable

Insulate piping

DC-1200M

End of main steam trap by installer

Condensate return

Blowdown valve by installer

45°

Pitch humidiﬁer branch 1/2" per 10' (0.4%) if distance from main to humidiﬁer is less than 10' (3.3 m)

Automatic warm-up: 28" (711 mm) min. Supervised warm-up:

1.5 × pipe diameter, 8" (203 mm) min.

If pipe is 4" (DN100) or larger, size drip for 50% of the condensate load at start-up. If pipe is less than 4" (DN100), size drip for 25% of the condensate load at start-up.

Branch steam trap by installer

Blowdown valve by installer

Branch trap recommended if distance from main to humidiﬁer is greater than 10' (3.3 m)

Condensate return

Pitch main 1/4" per 10' (0.2%)

Piping same size as humidiﬁer inlet strainer

To humidiﬁer. Inlet strainer must be within 3' (1 m) of humidiﬁer

Humidiﬁer isolation valve

Insulate piping

12" (305 mm) min.

4" (100 mm) min.

STEAM INJECTION INSTALLATION, OPERATION, AND MAINTENANCE MANUAL

OVERVIEW

Pressurized steam piping guidelines

FIGURE 12-1: ELEVATING CONDENSATE FROM A STEAM INJECTION HUMIDIFIER

Pitch 1/2" per 10' (0.4%)

Elevated condensate return main

1/2" pipe thread (DN15)

5' (1.5 m) maximum

Condensate return ﬂow

Inverted bucket steam trap

Check valve (swing type)

DC-1064

In certain installations, it is not possible to drain the humidiﬁer steam trap by gravity. The condensate must be lifted. Generally, lifting condensate is not recommended, but it can be done successfully by observing the following rules:

• Steam pressure. Theoretically, one pound (6.9 kPa) of steam pressure will lift condensate about 2' (0.6 m). But

in practice, because of pipe friction, pressure drop through a steam trap, and back pressure in a return line, we recommend maximum lift of 6" per pound (0.2 m per 6.9 kPa) of steam pressure at the trap. For example, a steam pressure of 5 psi (34.5 kPa) will provide a maximum lift of 2.5' (0.76 m). Lifting condensate more than 5' (1.5 m) should not be attempted.

• Steam trap. When lifting condensate, use an inverted bucket steam trap. Float and thermostatic (F&T) traps are

more prone to water hammer damage with a ﬂooded trap, which may occur when lifting condensate.

• Pipe size. The size of the vertical portion of the piping should be 1/2" pipe thread (DN15).

• Check valve (swing type). A low-pressure differential swing check valve should be installed adjacent to the trap.

This will prevent backﬂow of condensate into the humidiﬁer during periods of little or no steam pressure. Failure to do so could result in accumulated backﬂow discharging from the humidiﬁer when steam pressure is resumed. Spring-type check valves are not recommended, as they can reduce pressure available for condensate lifts.

Condensate lifting recommendations:

1. Condensate can be lifted for all steam jacket piping.

2. Condensate could be lifted for connection to separator, but performance could vary based on variable pressure at the separator.

3. Condensate cannot be lifted for connection on headers for Multiple-tube humidifiers (including Maxi-bank option).

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STEAM INJECTION INSTALLATION, OPERATION, AND MAINTENANCE MANUAL

Pressurized steam piping guidelines

FIGURE 13-1: MULTIPLE VALVE PLUMBING GUIDELINES

Isolation valve (by others)

From steam source

Install strainer within 3' (1 m) of humidiﬁer (see Note 2)

OVERVIEW

Piping to be same size as strainer

Piping to be same size as valves

Valve

Piping to be same size as separator inlet

Notes:

1. Dashed lines indicate provided by installer.

2. Steam valve and strainer sizes are provided by DriCalc, DriSteem's free sizing and selection software, available at www.dristeem.com.

mc_042811_1450

Separator

Steam trap

Separator

Steam trap

Union

Valve

Union

4" (100 mm)

To Multiple-tube header inlet

DC-1488

Piping to be same size as separator inlet

12" (305 mm)

STEAM INJECTION INSTALLATION, OPERATION, AND MAINTENANCE MANUAL

OVERVIEW

Condensate drain piping and trapping

FIGURE 14-1: CONDENSATE DRAIN PIPING AND TRAPS FOR STEAM INJECTION HUMIDIFIERS

P-trap dimensions

Condensate outlet

Drop

Lifting condensate

From P-trap or mechanical trap

Condensate pump*

Seal

Check valve

Mechanical trap dimensions

Typical model

Condensate outlet

Drop

Drip

F&T trap (shown) or inverted bucket trap

Notes: * Use condensate pump rated for 212 °F (100 °C) and suitable for lifting 250 gph (16 L/m)

at required head (60 kPa). Stainless steel condensate pump recommended when pumping condensate from systems using optional stainless steel components.

• If wasting condensate to drain, temper condensate to local code to prevent damage to drain plumbing.

• Dashed lines indicate provided by installer.

Stainless steel components model

Condensate outlet

Drip

Cooling

leg

Stainless steel thermostatic trap

mc_050211_1314

STEAM INJECTION INSTALLATION, OPERATION, AND MAINTENANCE MANUAL

Condensate drain piping and trapping

Table 15-1: Condensate drain piping and traps for Steam Injection humidifiers

Single-tube, Mini-bank, and Multiple-tube humidiﬁers

P-trap water seal

Piping from separator*** Piping from steam jackets Piping from header

Typical

model

Models with optional stainless steel components

Typical

model

Do not use Do not use Do not use Do not use Do not use Do not use

Models with optional

stainless steel

components

Typical

model

Models with optional stainless steel components

OVERVIEW

Area-type humidiﬁer

Piping

from

separator

Use with

minimum:

Drop: 8"

(203 mm)

Seal: 10"

(254 mm)

F&T trap

Inverted bucket trap*

Stainless steel thermostatic trap

Use if steam

pressure is ≤15 psi

(103.4 kPa):

Drop: 12" (305 mm)

Drip: 4" (102 mm)

Use if steam

pressure is >15 psi (103.4 kPa): Drop: 12" (305 mm)

Drip: 4" (102 mm)

Do not use

Use with stainless

steel

piping with

minimum:

Drip: 4" (102 mm)

Cooling leg: 24"

(610 mm)

Use only if not lifting

condensate and

steam pressure is

≤15 psi (103.4 kPa):

Drop: 12" (305 mm)

Drip: 4" (102 mm)

Use if lifting

condensate or if

steam pressure is

>15 psi (103.4 kPa):

Drop: 12" (305 mm)

Drip: 4" (102 mm)

Do not use

Do not use Do not use Do not use Do not use

Use with stainless

steel piping with

minimum:

Drip: 4" (102 mm)

Cooling leg: 24"

(610 mm)

Use with

minimum:

Drop: 12"

(305 mm)

Drip: 4"

(102 mm)

Do not use

Do not use Do not use

Use with stainless

steel piping with

minimum:

Drip: 4" (102 mm)

Do not use

Cooling leg: 24"

(610 mm)

Return condensate to boiler via

Yes Yes Ye s Yes Yes Yes No nonpressurized return line?

Return condensate by condensate

Yes Yes** Yes Yes** Yes Yes** Yes

pump?

Drain condensate to

Yes

†

Yes

†

Yes

†

Yes

†

Yes

†

Yes

†

Recommended

open drain?

Notes: * Trap may require priming after seasonal shutdown. ** DriSteem recommends using a stainless steel condensate pump when pumping condensate from systems using optional stainless steel components. *** During consistent load, there may not be enough steam pressure in the separator to lift condensate from the separator using steam. † If wasting condensate to drain, temper condensate to local code to prevent damage to drain plumbing.

mc_050211_1630

†

STEAM INJECTION INSTALLATION, OPERATION, AND MAINTENANCE MANUAL

OVERVIEW

Temperature switches

FIGURE 16-1: PNEUMATIC TEMPERATURE SWITCH STANDARD LOCATION

Pneumatic airﬂow switch (optional)

Set point controlling humidistat

20 psi (138 kPa) air supply

Duct high limit Required 0.007" (0.18 mm) restrictor

humidistat

(optional)

Separator

12" (305 mm) min.

DC-1190

mc_051011_1650

Steam trap

FIGURE 16-2: PNEUMATIC TEMPERATURE SWITCH ALTERNATE LOCATION

12" (305 mm) min.

Pneumatic temperature switch

DC-1192 mc_051011_1651

Pneumatic temperature switch

Steam trap

STEAM INJECTION INSTALLATION, OPERATION, AND MAINTENANCE MANUAL

Temperature switches

PNEUMATIC TEMPERATURE SWITCH NOTES:

• DriSteem's pneumatic temperature switch, designed for use with a pneumatic control system, prevents condensate discharge from a steam injection humidiﬁer during cold start or if the condensate return main becomes ﬂooded. It accomplishes this by bleeding off the pneumatic signal from the controlling humidistat, preventing the pneumatic humidiﬁer valve from opening until the steam trap has reached operating temperature.

• The pneumatic temperature switch has a self-contained air valve operated by a thermal disc that is normally open, bleeding off control air pressure. When steam comes in contact with the thermal disc, the ﬂuid inside the disc expands, causing the air valve to close, thus allowing the pneumatic control system air pressure to build up and to actuate the steam control valve.

• Install the tee containing the pneumatic temperature switch in the condensate drainage pipe line between the separator and the inlet to the steam trap, as shown in the drawings on Pages 16 and 18.

mc_051011_1652

OVERVIEW

STEAM INJECTION INSTALLATION, OPERATION, AND MAINTENANCE MANUAL

OVERVIEW

Temperature switches

FIGURE 18-1: ELECTRIC MODULATING TEMPERATURE SWITCH LOCATION

120 VAC primary

24 VAC secondary

Duct high limit humidistat (optional)

Airﬂow proving switch (optional)

Class 2 transformer (by installer) used with 24 VAC coil

Omit transformer when using 120 VAC coil

Steam trap

Electric modulating humidistat (optional) or control signal by others

Normally closed electric modulating valve (120 VAC or 24 VAC)

DC-1227 mc_051011_1653

12" (305 mm) min.

Electric temperature switch

STEAM INJECTION INSTALLATION, OPERATION, AND MAINTENANCE MANUAL

+ 44 hidden pages

DriSteem SINGLE-TUBE Series, MINI-BANK Series, MULTIPLE-TUBE Series, AREA-TYPE Series Installation, Operation And Maintenance Manual

Specifications and Main Features

Frequently Asked Questions

User Manual

OVERVIEW

Introduction

Available models

Basic components

Principle of operation

Sensor placement

Pressurized steam piping guidelines

Condensate drain piping and trapping

Temperature switches