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Volume 17 Issue May 2002

When considering low pressure boilersystems, the question has been raised,why save the condensate? Why notdump the used condensate to drain andsimply replenish the boiler with freshmake-up water? Because returning con-densate has value. Why? Because, thereturning condensate has a higher tem-perature than cold fresh water make-up.This means less energy that the boilermust add to heat the water. In most sys-tems, the condensate is treated withadditives to reduce corrosion. If conden-sate is dumped to drain and freshmake-up water is added, additional chem-icals would be required to condition thewater. Dumping hot condensate is ther-mal pollution, and the temperature ofwater that may be dumped to drain is reg-ulated. Also, fresh water is not free.Every gallon of condensate dumped todrain must be replaced with one gallon offresh water. For these reasons, conden-sate should be captured and reused.

BasicsIn a simple one-pipe steamsystem, energy is added towater in the boiler, to cre-ate steam. The steamflows through the inter-connecting piping to theradiation where it gives upits latent heat and con-denses back into water(condensate). The conden-sate flows back to theboiler through condensatereturn piping where itrepeats the cycle. Thesteam piping is designedfor very low pressurelosses, in the range of ounces. Thisenables the boiler to operate at low pres-sure. The condensate piping is pitchedback to the boiler so the condensate isreturned by gravity. The condensateflows back into the boiler when the

weight of a vertical column of condensateexceeds the pressure loss of the steampiping. The static height of condensate isthe A dimension shown in fig. 1. Theheight of the vertical column of conden-sate is 28 inches for each 1 psig boiler

BELL & GOSSETT DOMESTIC PUMP HOFFMAN SPECIALTY McDONNELL & MILLER

Fluid Handling

Selecting Condensate Transfer and Boiler Feed Equipment

See Condensate Transfer, pg. 2

Figure 1. A basic one-pipe upfeed system.

- Boiler Feed Units- Clinical Vacuum Units- Condensate Return Units- Heating Vacuum Systems- High Temerature Pumps- Low NPSH Pumps- Industrial Vacuum Units- Vacuum Condensate Units- Vacuum Boiler Feed Units

Domestic Pump - Boiler Feed Units- Condensate Return Units- Pilot Operated Valves- Pressure Regulators- Steam Traps- Steam Valves- Steam Vents- Temperature Control Valves- Vacuum Condensate Units- Vacuum Brakers- Water Vents

Hoffman Specialty

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- Boiler Level Controllers- Liquid Flow Switches

- Liquid Level Controls- Liquid Flow Switches- Low Water Cutoffs- Pump Controllers- Water Feeders

- Air Flow Switches- Boiler Water Feeders

McDonnell & Miller- Plate Heat Exchangers - Brazed Plate - Double Wall (UL Listed) - Removable Plates/Frame- Shell & Tube Exchangers - Double Wall (UL Listed) - Steam Heater Line (SU) - Straight Tube- U Tube

Bell & Gossett

1

Click on picture for product literature

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pressure. This simple system required noboiler feed pump to replenish the boilerwith condensate.

The simple steam system did not remainsimple. In time, the steam and conden-sate were separated into different lines.The one-pipe steam systems becametwo- pipe systems. Buildings and sys-tems became bigger. Horizontal runs ofreturn piping became longer. As a result,the installations lacked the vertical col-umn height of water needed to push thecondensate back into the boiler.

Installations lacking sufficient elevationto return the condensate by gravityneeded a condensate return unit.Returning condensate to the boiler withan electrically driven pump resolvedmany installation problems.

A condensate return unit is a device thatcollects condensate, then sends it back tothe boiler room with the use of a pump.The pumps are typically driven by elec-tric motors. This article discusses theselection of electrically driven centrifu-gal pumps.

Condensate return equipment varies insize, materials and complexity.However, these packages all containthree common components: a holdingtank to collect the condensate, a centrifu-gal pump, and an activating device tostart and stop the pump. The tanks orreceivers may be as small as 6 gallons orthey may hold as much as thousands ofgallons. They may be floor mounted,underground, or elevated on a stand toincrease the static pressure to the pump.The most common receiver materials arecast iron or steel. Cast iron receivers arevery durable; some manufacturers offeran extended warranty (20 years) againstcorrosion, and condensate pumps arespecifically designed for this duty. Thepump suction has a low-pressure drop toreduce NPSHR (discussed later). Thepump is designed for intermittent dutywith long periods of inactivity; and aswitch that senses liquid level activatesthe pumps. The most common is a sim-ple float switch or mechanical alternator.

Selecting CondensateEquipmentThe selection of condensate handlingequipment should be given carefulconsideration to maintain a properlybalanced efficient steam system. Thefactors to consider when selectingcondensate return equipment are:

The system size

The required discharge pressure

The NPSHA of the system

The amount of make-up requireddue to leakage

Flash steam and steam consumed inindustrial processes

The change in load rate during vari-ous time periods

The condensate return rate can be cal-culated from the square feetE.D.R.(equivalent direct radiation bydefinition) served, the lbs/hr of steamused, the BTU heat load, or the boilerhorsepower required. This informationwill enable you to select the size ofthe holding tank or receiver and therequired volume of condensate thepump must move.

Determine Pumping CapacityE.D.R. is the amount of heating sur-face that will give off 240 BTU/hrwhen filled with a heating medium at215F and surrounded by air at 70F.Steam is the medium in the radiation.When steam condenses in the radia-tion, it gives up its latent heat thenflows back as condensate. The latentheat of vaporization of 5 psig satu-rated steam is 960 BTU/lb. Using theconversion factor

1 E.D.R. = .25 lbs/hr. (condensate) and knowing the square feet of heat-ing surface (E.D.R.) the condensateunit will be serving, we can calculatethe rate that steam will condense.Factoring in the density of water atthe condensing temperature, we canconvert the lbs/hr of water to a morecommon volumetric flow rate - gal-lons per minute.

We have standardized on the conserva-tive factor of 500.

Using the formula lbs/hr 500 = gpm.

Therefore 1E.D.R. requires .0005 gal-lons/minute of steam condensing or

1000 E.D.R. = .5 gpm.

Converting the flow to gallons perminute simplifies pump and tank selec-tion. The tank or receiver is sized for 1-5minutes net storage capacity based on thereturn rate. Condensate pumps are typi-cally sized for 2 x the condensate returnrate. (See Conversion Factors) Determine the Required Discharge PressureThe pump must be sized to meet the totaldynamic head required by the applica-tion. This is accomplished by solving theequation:

Pa = static pressure, lbf/ft2

W = mass density, lbm/ft3

Za = elevation ft.V2a = average velocity g = constant 32.2 (lbm-ft)/(lbf-s2)hi = friction losses ft.Ep = work performed by the pump (ft/lbf)/lbmPb = static pressure, lbf/ft2

Zb = elevation ft.V2b = average velocity

The terms in this equation are the pump-ing energy required equals the change inpressure plus the elevation change plusthe velocity change plus losses due tofriction. The velocity change is often

2

CONDENSATE CONSIDERATIONSCondensate Transferfrom pg. 1


3CONDENSATE CONSIDERATIONS

negligible so the equation is simplified tothe following:

Overcome any pressure differences

Add static head to lift the condensate

Overcome losses in the return piping,fittings, and valves

Once youve summed these terms add anadditional 5 psig if the total pressure isbelow 50 psig. If the calculated sum isabove 50 psig add 10 psig. This is asafety factor that allows for wear in thesystem.

Determine the NPSHA

As with all pump applications, NPSHmust be considered. When selectingpumps for condensate this is especiallycritical. The amount of required head is afunction of the pump design and is calledNet Positive Suction Head Required(NPSHR). NPSHR is the amount of suc-tion head required to prevent pumpcavitation and is indicated on the pumpcurve. The NPSHR for a Model 609PFpump is illustrated in the curve above(figure 2) labeled NPSH REQ.If the pressure in the pump drops belowthe vapor pressure of the condensate,cavitation or flashing will occur. Eachapplication has an available net positivesuction head (NPSHA). NPSHA is afunction of the static head at the pumpsuction, velocity head, and vapor pres-sure of the liquid at the temperaturebeing pumped. The NPSHA must always

be greater than the NPSHR or noise andcavitation will occur. The formula forNPSHA is:

In a vented receiver, Pa is atmospheric.He is the height of condensate above thepump suction, determined by the conden-sate unit design. Hf is the friction lossesfrom the receiver to the pump suction.This is fixed by the condensate unit

design. Pv is the vapor pres-sure of the liquid at thepumping temperature. For aparticular, previouslydesigned condensate returnunit, the only variable is Pv.Since Pv is a function of tem-perature, once the condensatetemperature is known we candetermine NPSHA. TheHydraulic Institute recom-mends a margin ratio betweenthe available and requiredNPSH (NPSHA/NPSHR) forvarious centrifugal pumpapplications. Using building

services as the application category forboiler feed pumps or condensate returnpumps, the ratio margin suggested by theHydraulic Institute is 1.1 or 2minimum.The Hydraulic Institute developed thismargin ratio using field experience frommany pump manufacturers as the basis.

Condensate units are typically pre-engi-neered to ensure that NPSHA is greaterthan NPSHR for a given temperaturelimit. Most manufacturers catalog theircondensate return equipment by maxi-mum temperature. (There is a correctionfactor for increased elevation. Boilingpoint decreases 1F for every 500increase in elevation.)Condensate return units are primarilyused to transport condensate from the farreaches of a steam system back to theboiler room when gravity flow is no

longer feasible. In any system, there is atime lag between when steam leaves theboiler until it returns in the form of con-densate. The greatest time lag existsduring a cold start-up. In a cold system,the steam mains, radiators, and returnpiping are completely drained. When thesystem is put into operation, the steammains and radiators require a volume ofsteam to fill the system. The volume ofsteam must come from the boiler duringthis period and causes a drop of waterlevel in the boiler. Additional time isrequired for the condensate to flowthrough the return lines back to the boilerroom either by gravity or to be pumpedback from condensate transfer units.

The opposite condition occurs when thesystem is shut down; all the steam in themains and radiators is returned in theform of condensate and must be storedfor the next system start-up. During nor-mal operation fluctuating load rates willcause surges of steam output and conden-sate return to occur in the system. Thesteam boiler system should be designedwith an ample storage volume to com-pensate for the variations in flow rate.

In some systems, a condensate return unitcan be used to maintain the water level ina boiler. With this arrangement, conden-sate is fed into the boiler in response tothe water level in the pump receiver. Thereceiver is sized the same as a typicalcondensate transfer unit to provide oneminute storage capacity based on theboiler steaming rate. The float switch inthe condensate return unit starts andstops the pump in relation to the level inthe receiver.

With this arrangement, the system surgesoccur in the boiler due to the change inboiler load. The boiler is equipped withan automatic water feeder to add citymake-up into the boiler on low level toreplace condensate lost in the system.Using a condensate return unit to feed aboiler has proven successful in smallsteam space heating applications. Onlarger installations, the boiler does nothave an adequate storage volume to han-dle the system surges.

When a condensate return unit is used tosupply a boiler that does not have an ade-

Condensate Transferfrom pg. 2


Figure 2. The NPSH curve for a sample pump.

quate storage volume, the make-up watervalve on the boiler will add additionalmake-up water during start-up or heavysystem steam demand. When the conden-sate is later returned, the boiler will floodand shut off on high water. This willcause a constant cycle of adding make-up water only to later flood the boiler.This problem may also occur when anolder high water volume boiler isreplaced by a low water content boiler.The practical system size limit for a con-densate return unit feeding a boiler isapproximately 8,000 sq. ft. E.D.R. or 60boiler horsepower system size. The max-imum system size will vary withdifferent types of boilers having variousstorage capacities between high and lowoperating levels.

Boiler Feed UnitsSystems larger than 8,000 sq. ft. E.D.R.or 60 boiler horsepower use a boiler feedunit to supply condensate to the boiler.The boiler feed unit consists of a storagereceiver sized to store an adequate vol-ume of water to handle the system surgesor system time lag. The pumps arestarted and stopped to maintain the boilerwater level in the boiler.

The normal boiler level control switchmaintains a boiler water level within oneinch differential. When a boiler feed unitis used, the fresh water make-up is addedinto the boiler feed receiver not theboiler. The boiler feed receiver must besized large enough to prevent overflow-ing of condensate during system surges.The normal receiver sizing is to provide5 minutes storage volume for systems upto 30,000 sq. ft. E.D.R. or approximately200 boiler horsepower.

Larger systems should provide a mini-mum of 10 minutes storage volume.Large single story buildings requiringover 100,000 sq. ft. E.D.R. and campuscomplexes should provide a minimum of15 minutes storage volume. Oversizingthe boiler feed unit receiver does notaffect the system operation, it only addsto the initial cost. However, undersizingthe boiler feed receiver can cause an

overflow of returned con-densate which must bereplaced with fresh make-up water. This wastesheat, make-up water, andchemical treatment.

Once you have decided aboiler feed unit is neededfor the system, the fol-lowing information mustbe determined.

The unit load require-ments

The type of controlsystem required

The pump capacity

The pump discharge pressure

Select the basic unit

Select the desired accessories

Determine the Unit LoadRequirementsThe load requirement is based on theboiler capacity, not the system capacity.The boiler is normally rated in boilerhorsepower. It may also be rated inlbs/hr, square feet E.D.R., or BTU out-put. Convert this data to the boilersteaming rate, then convert this to gal-lons per minute using the relationshipsdetailed earlier.

Select the Type of ControlSystem RequiredThere are sev-eral choices intype of pipingarrangementsto meet variousrequirements.A simplearrangement isone (or two)pumps feedingone boiler.When thewater level inthe boilerdrops, thepump controlon the boileractivates thepump. When the water level in the boiler

reaches the correct level, the pump con-trol deactivates the pump. If the pumpcontrol is single level and a second boilerfeed pump is included on the unit, thesecond pump can be manually operatedas a standby.

If the pump control can detect two sepa-rate levels, the second pump can beautomatically activated as a standby ifthe water level in the boiler drops to thesecond level. Another option is auto-matic alternation which automaticallyswitches the lead pump after every acti-vation cycle. This ensures even wear oneach pump and prevents the lag pumpfrom sitting idle for long periods. (Seefigure 3) One duplex boiler feed unit can feed twoboilers. This arrangement has a dedicated

4

CONDENSATE CONSIDERATIONS



Figure 3. Automatically switching the lead pump after everyactivation cycle can ensure both pumps wear evenly andprevents the lag pump from sitting idle for long periods.

Figure 4. An example of a duplex boiler feed unit supplying two boilers.

pump for a dedicated boiler. When eitherboiler requires water, the pump dedicatedto that specific boiler will be activated.The two pumps can be manuallyswitched to the other boiler by switchingthe pumps on the selector switches andmanually closing and opening the valvesin condensate piping. If the boilers areequipped with two-level pump con-trollers and boiler feed valves areinstalled between the pumps and boilers,the standby pumps can be automaticallyactivated should the water level in theboiler recede to the second level. (See figure. 4)

A third arrangement is two boilers beingfed by three pumps. Each boiler has adedicated pump. The third pump is adedicated manual standby. This arrange-ment may be expanded by adding oneboiler feed pump for each additionalboiler. Similar to the previous example ifthe boilers are equipped with two-levelpump controllers and boiler feed valvesare installed between the pumps and boil-ers, the standby pumps can beautomatically activated should the waterlevel in the boilers drop below the secondlevel. (See figure 5)These control system examples illustratethree common (but not the only) methodsfor linking the boiler feed unit to theboiler. Unlike a condensate unit, a boiler

feed unit relies on external signals forpump control. When selecting the boilerfeed unit, the number of boilers beingfed, the number of pump control levelsbeing monitored, if boiler feed valves areused, type of standby, and type of alter-nation, are all system dependent criteriathat will affect the design of the boilerfeed unit.

Calculate the Pump CapacityThe individual pumps capacity shouldbe based on the boiler(s) they arerequired to feed. The pumps are normallysized for 1-1/2 to 3 times the boiler load.When boiler feed pumps are selected forcontinuous operation, they are normallysized for 1-1/2 times the boiler load.

Boiler Feed Pumps for intermittent oper-ation are normally sized for 2X the boilerload. When there is a danger of pumpcavitation or when turbine pumps areused, selecting the pumps at 3 x theboiler load is acceptable.

Calculate the Pump Discharge PressureThe required discharge pressure for aboiler feed unit is calculated similar to acondensate unit. It is the sum of statichead lift, friction losses in the piping, andthe pressure in the boiler. In addition tothe boiler pressure, a safety margin of 5or 10 psig is added. For boiler pressuresup to 50 psig, add 5 psig. For boiler pres-sures of 51 psig or higher add 10 psig for

safety.

Select the Basic UnitWe know the required tank size, con-trol system, and pump duty point.We now need to decide the type ofunit. Things to consider are conden-sate temperature, materials ofconstruction, and receiver location(underground, floor mounted, or ele-vated). Most manufacturers havepreselected packages of receiversand pumps to meet a specific boilerload. These preselected packages arestated in E.D.R. served or boilerhorsepower.

Select the Desired AccessoriesOnce the basic unit is determined, theoptions can be selected. A list of the typi-cal options are as follows:

Gauge glass will permit visual indicationof the water level in the receiver.

Thermometers help monitor the returntemperature and provide indication whensteam traps are not operating properly.

Discharge pressure gauges permit visualindication of the pumps performanceand are useful in adjusting the balancingvalves for maximum pump efficiencyand to prevent cavitation.

A gauge glass, thermometer, and dis-charge pressure gauge are highlyrecommended options. They simplifyinstallation and help monitor the system.They are used to troubleshoot systemproblems and are well worth the invest-ment.

A low water pump cut-off float switchmay be added to prevent pump operationon low water level. This will preventpumps from running dry which will dam-age pump seals. The low water cut-offoption is not recommended for boilerfeed units smaller than 100 gallons. Onsmall receivers, the cut-off float switchwill reduce the receivers net capacityconsiderably.

Alarm float switches and bells may beadded to indicate abnormal conditions inthe system.

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Figure 5. This is an example of two boilers being fed by three pumps.

CONDENSATE CONSIDERATIONS

Pump isolation valves permit pumpservice without shutting down the entiresystem and draining the receiver. Thesevalves permit complete pump removalfor bench test inspection or wear ringreplacement.

Manholes give access to the inside ofthe tank for inspection.

Inlet basket strainers are connectedbetween the return line (coming to theunit) and the receiver. This is the collec-tion point for dirt and debris that form inthe system. They have a large dirt pocketand easy access for easy maintenance.Strainers should never be installed in thepump suction piping. The additional fric-tional loss through the strainer wouldreduce the NPSH available to the pumpand may cause cavitation.

Sparge tubes or steam distributiontubes are submerged tubes that injectsteam into the boiler tank to preheat thecondensate. Preheating reduces thermalshock to the boiler especially when largeamounts of fresh water make-up areadded to the system.

Corrosion inhibitor anodes are zinc ormagnesium rods threaded into the tank.The anode metal is more active andcreates a galvanic current flow. Theanode corrodes and provides a protectingeffect to the tank. In time the (sacrificed)anode will be chemically consumed andit must be replaced.

Pumps Designed forHandling Hot CondensateCertain characteristics make a pumpmore desirable for handling hot conden-sate. Centrifugal and turbine pumps arecommonly used for condensate handling.

A condensate pump should have:

A low NPSHR

A low sensitivity to sediment and cor-rosion

A low inertia for frequent start & stops

The ability to start after long periodsof inactivity

Generous running clearances to retaintheir original capacity after years of service

Earlier in this article we presented a briefdescription of NPSHA and explained thatin all applications the NPSHA (available)must be greater than the NPSHR(required) for the application to functionproperly. We also stated that NPSHA isprimarily determined by temperature.Elevating the receiver for additional

static head may increase NPSHA. OnceNPSHA is determined, a condensate unitmust be selected with a lower NPSHR.Condensate pumps are designed with alow NPSHR. Their suction size is largefor low friction losses. Their impellersare designed to minimize the pressuredrop as condensate is pulled into thevanes. If the pressure at this point dropsbelow the vapor pressure of the conden-

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One Boiler Horsepower = 140 Sq. Ft. EDR or 33,475 BTU/Hr, or 34.5 Lbs./HrSteam at 212 F.

1000 Sq. Ft EDR yields .5 GPM condensate

To convert Sq. Ft. EDR to Lbs. Of condensate - Divide Sq. Ft. by 4

.25 Lbs./Hr. condensate = 1 Sq. Ft. EDR

One Sq. Ft. EDR (steam) = 240 BTU/Hr. with 215 F. steam filling radiator and70 F. air surrounding radiator.

To convert BTU/Hr. to Lbs./Hr. - Divide BTU/Hr. by 960One PSI = 2.307 Feet Water Column (Cold)One PSI = 2.41 Feet Water Column (Hot)One PSI = 2.036 Inches MercuryOne Inch Mercury = 13.6 Inches Water Column

Sizing Boiler Feed or Condensate Return Pumps:If boiler is under 50 PSI, size pump to discharge at 5 PSI above working pressure.

If boiler is 50 PSI or greater, size pump to discharge at 10 PSI above workingpressure.

Size condensate receivers for 1 min. net storage capacity based on return rate.

Size boiler feed receivers:5 min. net storage for systems up to 200 Boiler HP.

10 min. net storage for systems above 200 Boiler HP.

15 min. net storage for systems that exceed 100,000 Sq. Ft. EDR or 700 BoilerHP.

Size condensate pumps at 2 times condensate return rate

Size boiler feed pumps at 2 times boiler evaporation rate or .14 GPM/Boiler HP(continuous running boiler pumps may be sized at 1-1/2 times boiler evaporationrate or .104 GPM/Boiler HP. When there is a danger of pump cavitation, or whenturbine pumps are used, select pumps for 3 times the evaporation rate.

CONVERSION FACTORSSee Condensate Transfer, pg. 7

sate cavitation will occur. Some conden-sate pumps include an inducer ahead ofthe impeller. The axial flow inducerdevelops a positive pressure at the eye ofthe centrifugal impeller, lowering theNPSHR. These specially designed pumpscan handle condensate close to its boilingpoint.

Sediment and corrosion are prevalent incondensate return systems. Condensatereturn units are designed with a low sen-sitivity to both. Large strainers areinstalled on the receivers, keeping largeparticles out of the receiver. Typicallythe strainers are designed for easy clean-ing with large dirt pockets to minimizemaintenance. The pumps have generousrunning clearances and retain near theiroriginal capacity after years of service.

Condensate pumps are selected to returncondensate at twice the system condens-ing rate. If a system sends condensateback at the rate of 10 GPM, the pump issized to return it at 20 GPM. This enablesthe pump to return the condensatequickly and allows the pump to keep upduring peak periods and start up.

During normal operation the pump is ona short start and stop frequency. One-minute pumping, two minutes stopped.Pumps that operate at a higher speed(3500 RPM) for a given duty point pro-duce lower inertia loads on the pumpshaft when compared to low speed (1750RPM) pumps. However, there is a tradeoff: higher speeds produce more noiseand require higher NPSHR. For mostapplications, the high-speed pump is pre-ferred for lower cost and lower inertialoads.

Many condensate transfer units operateseasonally with long periods of inactiv-ity. These units may sit unused formonths. Pump materials are selected toreduce corrosion between the impellerand volute. Bronze wear rings areinstalled in the volute to minimize gal-vanic reaction.

In SummaryWhen selecting condensate transfer units,first collect all pertinent information aboutthe application. Determine the total radia-tion being served or system size, therequired pressure, condensate temperature,amount of make-up water added, andexpected fluctuations in the load. Thisinformation will enable you to select the

basic unit, the required receiver size andpump needed.

When selecting boiler feed equipment theprocess is similar; gather the necessaryinformation about the system, and deter-mine the boiler capacity, boiler operatingpressure and returning condensate tempera-ture. This information will help you selectthe basic unit, the receiver size, pumpcapacity, and type of control system.

Once the basic condensate transfer or boilerfeed unit is selected, choose the options thatmeet your specifications for the specificapplication. Gauge glass, thermometer, anddischarge pressure gauge are options thathelp monitor the system and aid in trou-bleshooting. Standby pumps, alternatingcontrollers and high level alarms increasereliability.

Condensate transfer and boiler feed unitsare specifically designed for this duty.Properly selected and installed, these unitswill provide you with many years of trou-ble-free service.

This article was written by Bell &Gossett engineers and was originallypublished in the August 2001 issueof Engineered Systems magazine.Reprinted by permission.


- Boiler Feed Units- Clinical Vacuum Units- Condensate Return Units- Heating Vacuum Systems- High Temerature Pumps- Low NPSH Pumps- Industrial Vacuum Units- Vacuum Condensate Units- Vacuum Boiler Feed Units

Domestic Pump - Boiler Feed Units- Condensate Return Units- Pilot Operated Valves- Pressure Regulators- Steam Traps- Steam Valves- Steam Vents- Temperature Control Valves- Vacuum Condensate Units- Vacuum Brakers- Water Vents

Hoffman Specialty

- Boiler Level Controllers- Liquid Flow Switches

- Liquid Level Controls- Liquid Flow Switches- Low Water Cutoffs- Pump Controllers- Water Feeders

- Air Flow Switches- Boiler Water Feeders

McDonnell & Miller- Plate Heat Exchangers - Brazed Plate - Double Wall (UL Listed) - Removable Plates/Frame- Shell & Tube Exchangers - Double Wall (UL Listed) - Steam Heater Line (SU) - Straight Tube- U Tube

Bell & Gossett

Copyright ITT Industries, Inc., 2004



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