Steam Traps and Steam Trap Testing

What are steam traps?

To be able to operate a plant over along period with an optimumefficiency the choice of the correctvalves is of vital importance.Amongst these valves are steamtraps which have an important roleto play. Steam must be trappedwithin heating equipment until it hassurrendered all heat energy, atwhich point the condensate therebyformed must be immediately dis-charged.

The optimum efficiency of a steam-heated plant is dependent upon theperformance of steam traps.One type of steam trap cannot beequally well suited for the variousapplications and requirements,therefore GESTRA offers a com-prehensive steam trap rangedeveloped and refined on practicalapplications over the years.The choice of the steam trap typedepends, of course, on the plantcondition. We are willingly preparedto assist you in selecting the mosteconomic solution for your parti-cular application.

What are the advantages of GESTRAsteam traps?◗ Easy maintenance – our traps can be

checked, cleaned and repaired without being removed from the pipework

◗ Interchangeable – our various trap types have standardized face-to-face dimen-sions, sizes and end connections and are therefore interchangeable without any modification to the pipe layout.

◗ Tight shut-off, without loss of live steam.◗ Automatic air-venting.◗ Unaffected by dirt.◗ Production tested – besides the legally

required tests (e.g. hydraulic test) our trap regulators are tested under operating conditions (steam, condensate).

◗ Complies with recognized standards – our traps meet the relevant DIN standards and regulations and are in accordance with the AD bulletins (AD – Arbeits-gemeinschaft Druckbehälter = German pressure vessel regulations authority) with regard to choice of material, pressure and temperature ratings. On request test certificates to EN 10204.

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The GESTRA Steam Trap Range

The three different steam trap types

BKThe BK is a thermostatic steam trapwith Duo stainless (bimetallic)regulator. Advantage: particularly robust

MKThe MK is a thermostatic steam trapwith membrane regulator.Advantage: very sensitive responsecharacteristic.

UNAThe UNA is a float trap.Advantage: condensate dischargeat extreme and sudden condensateflowrate and pressure fluctuations.

Tra

p t

ype

BK

w

ith

bim

etal

lic

reg

ulat

or

Tra

p t

ype

MK

wit

h m

emb

rane

re

gul

ato

r

Bal

l flo

at t

rap

ty

pe

UN

A w

ith

Dup

lex

cont

rol

Bal

l flo

at t

rap

typ

e U

NA

wit

hS

imp

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cont

rol 1. Ratings:

1 = Excellent2 = Good3 = Fair or conditional– = Not recommended, unsuitable

Steam trap types

Short Guide to Steam Trap Selection

Criteria Please note:

1. Operation with Condensate from steam 1 1 1 1 For “cold” condensates or condensates with a different condensates Condensate from compressed air – – – 1 saturation curve deviating from that of water only

Condensate, distillate from float traps featuring Simplex controlchemical products (without thermal venting) can be used.

2. Different modes Continuous operation:of operation Constant formation of condensate; 2 1 1 1

flowrate and pressure vary

Discontinuous operation:Intermittent formation of condensate; 2 1 1 3*) *) e. g. air venting difficultiesflowrate and pressure vary strongly

Any operation: *) Air venting difficultiesHeat exchanger may be controlled 3**) 2 1 3*) **) With partial load (reduced differential pressure)on the steam side flowrate possibly not sufficient

3. Operation with Up to approx. 30% of upstream pressure 1 1 1 1back pressure > 30 % of upstream pressure 3 1 1 1

4. Sensitivity to dirt Highly contaminated condensate 1 1 1 1

5. Air-venting Automatic 1 1 1 3*) *) Manual air-venting

6. Condensate Condensate temperature nearly This may apply to small heat exchangersdischarge at boiling temperature (e. g. laboratory equipment)definite *) Might require special membrane regulatortemperatures Condensate undercooling *) with U-type regulator

approx. 30 K (required) **) with U-type capsule

Condensate undercooling *) If possible use steam trap with adjustable adjustable discharge temperature UBK

7. Frost resistance 1 1 1*) 3*) *) Only ensured with V-type design

8. Condensate Intermittent condensate formation 1 1 1 1discharge without Reduced condensate formation (< 10kg/h) 1 1 1 1loss of live steam Continuous condensate formation (> 10kg/h) 1 1 1 1

9. Resistance to waterhammer 1 1*) 3 3 *) Built-in non-return valve

10. Non-return valve action 1 1*) – – *) Built-in non-return valve

11. Application in vacuum 3 2 1 1

12. Installation in any position 1 1 – –

13. Easy of maintenance 1 1 1 1

14. Service life of control unit 1 2 1 1

– – – 1

3 2*) 1 1

1*) 1**) – –

3*) – 1 1

Not all steam trap types are equally suitable for a given application.Depending on the operating conditions and service in question,one or more systems will be particularly well suited.The following table contains 14 criteria for steam trap selectionbased on the operation of the plant and the specific requirementson the part of the plant owner.

Thermostatic steam traps withDuo stainless steel (bimetallic)regulator Pressure ratings up to PN 630.

For roughest operating condi-tions. Unexcelled service life.

Operating principle resulting in a sturdy design unaffected bywaterhammer and frost.

May also be used as air vents.

Operation

Opening and closing are controlledby the temperature sensor of Duostainless steel plates and the stagenozzle operating together. Duringstart-up of the plant and in thepresence of cold condensate andair the Duostainless steelplates are flat. Theservicepressure acts in theopeningdirection, thevalve is completely open.

With rising condensate temperaturethe plates deflect and draw the stagenozzle towards the closed position(a thermostatic process). Theservice pressure and the pressurebuilt up in the stage-nozzle chamberby flashing produce an oppositeforce (a thermodynamic process).The orifice area is determined by the prevailing state of equilibriumbetween the temperature-dependentclosing forceand the pressure-related openingforce.

Immediately below saturation tem-perature (boiling temperature) theplates are deflected to such anextent that the stage nozzle isalmost closed. As a consequencethe pressure in the stage-nozzlechamber decreases and breaksdown as the flashing across thestage nozzle then closes. The de-flection of the Duo stainless steelplates created by the temperature isnot sufficient to produce, over thecomplete pressure range, the forcerequired to counteract the forceacting on the stage nozzle in theopening direction. The plates aretherefore arranged in a stack whichacts as a spring having a character-istic that adapts itself to the forceacting on the stage nozzle varyingwith the service pressure. Thermo-static and spring characteristics arebalanced so that the opening andclosing tem-peratures arealways just afew degreesbelowsaturationtemperature.

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Duo Steam Traps BK

Thermovit regulator ◗Light and compact regulatorunit, replaceable withoutremoving body from pipeline.Withstands waterhammer andfreezing. Easy maintenance.

Large-surface strainer ◗

Stage nozzle ◗Thermodynamic control. Wear resistant. Freely mountedfor non-return valve action.

Temperature feeler of Duostainless steel plates ◗Thermostatic control. Corrosion-resistant throughout, fatigue-free, not subject to ageing.

Rhombus-shaped cover ◗secured with only two bolts,which are easy to insert andeasy to use in restrictedspaces.

Metal base bushing◗

Recessed flat gasket for superior sealing

◗

5

Max. differ- Connections, DNType Material ential pressure

bar (psi) Flanged Screwed Socket-weld Butt-weld

BK 45 C 22.8 22 (320) 15–25 mm (1/2"–1") 1/2"–1" 1/2"–1" 15–25 mm (1/2"–1")

BK 15 C 22.8 22 (465) 40–50 mm (11/2"–2") 11/2"–2" 40–50 mm (11/2"–2")

BK 46 15 Mo 3 32 (580) 15–25 mm (1/2"–1") 11/2" 11/2"

BK 27 15 Mo 3 45 (650) 40–50 mm (11/2"–2") 11/2"–2" 40–50 mm (11/2"–2")

BK 28 15 Mo 3 85 (1230) 15–25 mm (1/2"–1") 1/2"–1" 15–25 mm (1/2"–1")

BK 29 13 CrMo 44 110 (1600) 15–25 mm (1/2"–1") 1/2"–1" 15–25 mm (1/2"–1")

BK 212 10 CrMo 9 10 250 (3625) 15–25 mm (1/2"–1") 1/2"–1" 15–25 mm (1/2"–1")10 CrMo VNb 91

BK 28 ASTM A 182 F 12 85 (1230) 15–25 mm (1/2"–1") 1/2"–1" 15–25 mm (1/2"–1")

BK 29 ASTM A 182 F 12 110 (1600) 15–25 mm (1/2"–1") 1/2"–1" 15–25 mm (1/2"–1")

BK 212 ASTM A 182 F 22 250 (3625) 15–25 mm (1/2"–1") 1/2"–1" 15–25 mm (1/2"–1")

BK Types and Connections

6

BK 15BK 45BK 46

BK 27

The BK traps at a glance

7

BK 28, BK 29 BK 212

Screwed socketsButt-weld ends

Socket-weld endsFlanged ends

Steam trap BK used on autoclaves

in an insulating block works

Thermostatic steam traps with membrane regulator. Pressureratings up to PN 40. Unexcelledregulating accuracy due tothermostatic capsule.

May also be used for thermal air-venting.

With Tandem seat (doublesealing) for low condensateflowrates. For larger conden-sate flowrates with single seat.

The main feature of the MK traps isan unusually sensitive response.They are particularly suited for thedrainage of such heat exchangersthat would appreciably be affectedin their operation by even theslightest banking-up of condensate.The operation of the trap is neitherinfluenced by its position of install-ation nor by upstream or backpressure. The thermostatic capsuleand all other internals are made ofcorrosion-resistant materials. Themembrane of Hastelloy® is com-pletely corrosion-resistant even withacid condensate and condensatecontaining chlorides.

Two different designs of the thermo-static capsule are available:◗standard capsule “N” for instant-aneous condensate discharge with-out any banking-up. Opening tem-perature approximately 10 K (degC)below saturation temperature. ◗undercooling capsule “U” foradditional energy savings (utilizationof a certain amount of sensible heatby banking-up of condensate, de-creasing the amount of flash steam).Opening temperature approximately30 K (degC) below saturationtemperature. The integral non-return valve with hollow cone andreduced mass protects the capsulefrom waterhammer. The asbestos-free cover gasket is maintenance-free. The large-surface strainerprotects the trap from dirt ensuringlonger maintenance intervals. Forparticularly aggressive condensateand special hygienic requirementsthe MK 45 A is available madecompletely of stainless steel.

Operation Membrane regulator

Opening: The capsule of themembrane regulator is filled with aliquid having an evaporation tem-perature which is just a few degreesbelow the saturation temperature of water. During shut-down or start-up of the plant, i.e. if cold con-densate is present, the liquid fillingis completely condensed. Thepressure in the capsule is lower thanthe surrounding pressure (service

pressure); the membrane with thevalve disc is pushed in the openingdirection. Closing: With rising con-densate temperature, the liquidfilling starts to evaporate. Thepressure in the capsule rises; themembrane with the valve disc ismoved in the closing direction. Just before the condensate hasreached its saturation temperature,the trap is closed completely.

Tandem seat

The self-centering valve cone �ensures steam-tight closure. Withrising temperatures the additionalflat seat � closes too and provides a further guarantee of tightness,even in the presence of dirtparticles. Moreover the pressuredrop across the orifice area of thetrap in two stages reduces wearand enhances the life of the trap.

Steam Traps MK

8

During plant operationSeat 1 closes (regulator is pushed in the closed position)

Trap closedBoth seats are tightly shut off

�

�

�

�

Thermostatic capsule ◗Regulator unit replaceablewithout removing body frompipeline. Precise reaction to any change in temperature.Corrugated membrane ofHastelloy®. High elasticity, long service life.

Rhombus-shaped cover ◗secured with only two bolts, which are easy to insert and easyto use in restricted spaces.

Large-surface strainer ◗

Tandem seat ◗Double sealing.

Non-return valve with hollowcone and reduced mass ◗Quick closing in the event of waterhammer.

Metal base bushing◗

Recessed flat gasket for superior sealing

9

◗

MK Types and Connections

10

MK 45MK 45 AMK 25/2S (DN 25)MK 25/2S3 (DN 25)MK 25/2 (DN 40/50)MK 25/2S (DN 40/50)

Max. differ- Connections, DNType Material ential pressure

bar (psi) Flanged Screwed Socket-weld Butt-weld

MK 45-1 C 22.8 22 (320) 15–25 mm (1/2"–1") 1/2"–1" 1/2"–1" 15–25 mm (1/2"–1")

MK 45-2 C 22.8 22 (320) 15–25 mm (1/2"–1") 1/2"–1" 1/2"–1" 15–25 mm (1/2"–1")

MK 25/2S C 22.8 22 (320) 25 mm (1") 1" 1" 25 mm (1")2 capsules

MK 25/2S3 C 22.8 22 (320) 25 mm (1") 1" 1" 25 mm (1")3 capsules

MK 25/2 C 22.8 22 (320) 40, 50 mm (11/2", 2") 11/2"–2" 11/2"–2"4 capsules

MK 25/2S C 22.8 22 (320) 40, 50 mm (11/2", 2") 11/2"–2" 11/2"–2"9 capsules

MK 45 A-1 1.4404 22 (320) 15–25 mm (1/2"–1") 1/2"–1" 1/2"–1" 15–25 mm (1/2"–1")

MK 45 A-2 1.4404 22 (320) 15–25 mm (1/2"–1") 1/2"–1" 1/2"–1" 15–25 mm (1/2"–1")

The MK steam traps at a glance

MK 45-1MK 45 A-1

MK 45-2MK 45 A-2

MK 25/2S DN 40/50MK 25/2 DN 40/50

MK 25/2S DN 25 MK 25/2 S3

Screwed socketsButt-weld ends

Socket-weld endsFlanged ends

MK 36/51

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Duo Super Steam Traps TK forvery large condensate flowratesup to PN 25

The traps with thermostatic pilotcontrol using thermostatic capsulesare used for the discharge of verylarge amounts of condensate. Theregulating characteristic and thecontrol effect of these traps aresimilar to those of the membranetraps. If, for a special application,the trap must not close completely,a leak passage can be adjusted. Itis, however, also possible to restrictthe valve lift to obtain continuousoperation.

To guarantee a rapid response ofthe traps they are adjusted at thefactory so that a leak passage ofapprox. 1–2% is obtained.

Max. differ- Connections, DNType Material ential pressure

bar (psi) Flanged

TK 23 Cast iron GG-25 10 (145) 50, 65, 80, 100 mm (2", 21/2", 3", 4")

TK 24 Cast steel GS-C 25 14 (200) 50, 65, 80, 100 mm(2", 21/2", 3", 4")

The TK traps at a glance

Max. differ- Connections, DNType Material ential pressure

bar (psi) Screwed Socket-weld

MK 35/31 Forged steel C 22.8 21 (305) 3/8", 1/2" 3/8", 1/2"

MK 35/32 Forged steel C 22.8 21 (305) 3/8", 1/2" 3/8", 1/2"

MK 36/51 S. S. X5 CrNi 1810 32 (465) 1/4", 3/4"

MK 20 Malleable 4.5 (65) Inlet: threaded male withcast iron union nut and threadedGTW-40 nipple. Outlet: screwed

BSP 1/2", 3/4"

The compact and low-pressure MK traps at a glance

MK 35/31

TK 23/24 DN 50

The compact and

low-pressure MK traps

up to PN 40

MK 20

Pressure ratings up to PN 160For condensate dischargewithout banking-up even withload and pressure fluctuations.

Ball float traps are also suitable forthe discharge of cold condensates,distillates and condensate derivedfrom chemical products. They oper-ate without any banking-up evenwith considerable load and pres-sure fluctuations and at any backpressure. Compared with other traptypes, they are the least affected bydirt. The traps are supplied with“Duplex” control (thermostaticbellows for automatic air-venting),alternatively with “Simplex” control(without bellows) and hand ventvalve. The control unit is easilyaccessible after removing the trapcover, and can be changed as acomplete unit without removing thetrap from the line. The rolling ball

valve produces very little friction andcan be operated with a minimum of force. This results in small, lighttraps but with large capacities.

UNA 13 PN 16, UNA 15 PN 25compact trap for small condensateflowrates. Design “h” for horizontaland design “v” for vertical pipework.A conversion of “h” design to “v”design or vice versa is possible byrepositioning body and control unitto suit the pipework layout.

UNA 23 PN 16, UNA 25 PN 40,UNA 26 PN 40For large condensate flowrates.Design “h” for horizontal and design“v” for vertical pipework.

For particularly aggressive fluids orspecial hygienic requirements the UNA 26 and UNA 15 are also avail-able made completely of stainlesssteel.

UNA 27h PN 63For differential pressures up to 45bar. Installation in horizontal pipe-work.

UNA 39 PN 160Float trap controlled by the float,only for smaller flowrates.

UNA 39, max. orifice 140, PN 160 The trap operates with pilot control(without auxiliary power). It thereforedischarges large amounts of con-densate at high pressures withoutrequiring a large trap body.

Operation

Air-venting whensystem is cold (start-up condition).

Air-venting duringoperation(temperature lowerthan standard steamtemperature).

Discharge of boilinghot condensate(temperature equals saturationtemperature).

Ball Float Traps UNA

12

13

Upper plug ◗Installation of manual ventvalve or air balance possible.

Thermostatic bellows ◗for automatic air-venting(“Duplex” control). Withoutbellows (“Simplex” control) for cold fluids.

Control unit ◗Easy maintenance afteropening cover. Complete unitmay be changed withoutremoving body from pipeline.

Deflector ◗guarantees the deflection ofthe condensate stream andreduces wear on the trap body

Closing unit (orifice) ◗A selection of orifice sizes for high and low pressureapplications.

Rolling ball valve ◗Low friction.

Closed ball float ◗

Bolted cover ◗Closed or sightglass cover(water-level indicator).

Lower plug ◗Draining of trap or for installation of lifting lever.

UNA Types and Connections

14

UNA 1...v UNA 1...h

UNA 2...hUNA 2...v

UNA 27 h

UNA Ball Float Traps at a glance

BodyC 22.8

BodyC 22.8

CoverGS C-25

Body

Cover

CoverGS C-25

1.4571

1.4308

UNA 39

15

Max. differ- Connections, DNType Material ential pressure

bar (psi) Flanged Screwed Socket-weld Butt-weld

UNA 13hGG-25 13 (185) 15–25 mm (1/2"–1") 1/2"–1"

UNA 13v

UNA 15h21 (305) 15–25 mm (1/2"–1") 1/2"–1" 1/2"–1" 15–25 mm (1/2"–1")

UNA 15v

UNA 15hUNA 15v 21 (305) 15–25 mm (1/2"–1") 1/2"–1"Stainless steel

UNA 23hGG-25 13 (185) 15–50 mm (1/2"–2")

UNA 23v

UNA 25hGG-40.3 32 (465) 15–50 mm (1/2"–2")

UNA 25v

UNA 26h32 (465) 15–50 mm (1/2"–2")

1/2"–2" 1/2"–2" 15–50 mm (1/2"–2")UNA 26v

UNA 26h1.4408 32 (465) 15–50 mm (1/2"–2") 1/2"–2" 1/2"–2" 15–50 mm (1/2"–2")

Stainless steel

UNA 27 GS-22 Mo 4 45 (650) 25, 40, 50 mm (1",11/2", 2") 1", 11/2"–2" 25, 40, 50 mm (1",11/2, 2")

UNA 39 13 CrMo 44 140 (2030) 15, 25, 50 mm (1/2",1", 2") 15, 25, 50 mm (1/2",1", 2")

Liquid drainer for compressed-air and gas systems PN 16

For continuous draining of gas andcompressed-air systems, float trapswith “Simplex” control units (i.e.without thermostatic air vent) areused. To ensure perfect drainage,the air traps can be fitted with abalance pipe which allows air in the trap body to escape so that itcannot obstruct the flow of con-densate into the trap. A balancepipe is not necessary if the trap isinstalled directly below the equip-ment to be drained and if the drainline runs vertically. In this instancethe pipe leading to the trap shouldbe of sufficient size so that any air

can escape by bubbling through the condensate. All air traps areequipped with a plug allowing abalance line to be connected, andare fitted with a float lifting lever tofacilitate manual purging of the valvearea. UNA traps are fitted with aperbunan rubber valve ball to pro-vide tight closure; a stainless steelvalve ball may be specified forhigher temperatures and pressures.In the case of very small conden-sate flowrates the tightness of thevalve closure should be considered.

Float-operated valve for special applications

16

Max. differ- Connections, DNType Material ential pressure

bar (psi) Flanged Screwed(density 1 kg/dm3)

UNA 13 P, h+v Cast iron GG-25 16 (130) 15, 20, 25 mm (1/2"–1") 1/2", 3/4", 1"

The liquid drainer at a glance

Air or gas line ◗ ◗Air-balance pipe

Collectingpocket ◗

with or without valve;valve spindle horizontal

Float trap for horizontal installation◗

UNA 13 P

Other traps for special applicationsK

Steam Trap UBK 46 Pressure ratings up to PN 40

The UBK 46 is a special version ofthe BK range of traps designed tosave energy by holding back thecondensate until it has cooled downto the adjustable discharge tem-perature, thus permitting the utiliza-tion of the sensible heat of the

condensate and avoiding flashsteam. The Duo stainless steelthermostat is corrosion-resistantand unaffected by waterhammer.Installation in any position.

With large-surface Y-type strainer: Main field of application: steamheated tracing systems.

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SMK 22 Pressure ratings up to PN 10

The thermostatic steam trap featuresminimum stagnant area and a corro-sion-resistant membrane regulatorunaffected by waterhammer. Usedfor discharging of condensate and airventing of steam in sterile and asepticapplications. The membrane regula-tor features a self-centering valvecone that can move freely, therebyensuring steamtight shut-off unaffect-ed by particulate matter. High sensiti-vity thanks to reduced dimensions of

the regulator (evaporation thermo-stat). Automatic air-venting anddischarge of condensate without any banking-up within the ratedpressure/ temperature range. Theopening temperature is approx. 5 Kbelow the boiling point. All parts incontact with the fluid are made ofstainless steel and the body gasketis of EPDM (O-ring) in accordancewith the regulations specified by theFood and Drug Administration (FDA).The surface roughness Ra of thewetted surfaces is ≤ 0.8 µm.

Max. differ- Connections, DNType Material ential pressure

bar (psi) Flanged Screwed Socket-weld

UBK 46 Forged steel C 22.8 32 (465) 15–25 mm ( 1/2"–1") 1/2"–1" 1/2"–1"

The UBK trap at a glance

Max. differ- Connections, DNType Material ential pressure

bar (psi) Butt-weld ends

SMK 22 S.S. 1.4435 6 (87) DN 15, 1/2"

The SMK trap at a glance

ISO 1127, series 1ISO 11850, series 2

line®STERI

Condensate Drain Valve AK Pressure ratings up to PN 40

Automatic drain valve for rapidcondensate discharge during thestart-up of steam plants and fordraining the remaining condensateat shut-down. The formation of avacuum and possible frost damageare prevented. To avoid freezing ofthe AK, the drain line should bekept as short as possible and thevalve be included in the thermalinsulation. The valve is controlledonly by the pressure. It replaces amanually operated by-pass valve.

Draining a steam line at start-up

At start-up of the steam line thepressure in the line is initally zero,although steam is already conden-sing. However, the condensateformed cannot be discharged bythe steam trap into the rising con-densate line, as there is not yet anydifferential pressure available to liftthe condensate. In this case, in thepast a by-pass valve mounted atthe lowest point of the system hadto be openend by hand, so that

Other traps for special applications

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Max. differ- Connections, DNType Material ential pressure

bar (psi) Flanged Screwed

AK 45 Forged steel C 22.8 0.8 (11.6) 15–25 mm (1/2"–1") 1/2"–1"

The AK condensate drain valve at a glance

Steam ◗

AK 45

Condensate

the condensate could drain freely.As shown in the schematic re-presentation, the drain valve AK 45ensures automatic condensatedischarge until the pressure in thesteam line has reached 0.8 bar(11.6 psi) (factory-set closingpressure). This pressure in thesteam line is sufficient for the steamtrap to discharge the condensateinto the condensate-return line. At this pressure the AK 45 closesinstantaneously and automatically.When the steam system is shutdown, the pressure in the steamline drops slowly. As soon as thepressure has dropped below 0.8bar, the AK 45 opens, dischargesthe remaining condensate andprevents the formation of vacuum.

Steam Traps for Large-Scale Installations

The steam traps BK 35 Class 300and DK 47/57 (similar to Class 400)are distinguished by their compact,lightweight design and suggestthemselves as the ideal economicalsolution for medium and large-scaleinstallations.

Further GESTRA valves suitable for condensate discharge

Regulating steam trap:Continuous blowdown valve BA36 Pressure ratings up to PN 40

The valve can also be used asthermodynamic steam trap withstage nozzle (without samplingvalve).

Control valves ZK with radialstage nozzle For pressure ratings up to PN 630

The valve can also be used forinjection-cooling, level and leak-offcontrol, as well as for drainageduties.

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ZK 29BA 36

ZK 610 used as preheater

condensate drain valvein a power station

The steam traps for large-scale installations at a glance

BK 35 DK 47 DK 57

Material Max. differ- ConnectionsType ential pressure

ASTM DIN [bar] Screwed NPT Screwed BSP Socket-weld Flange

BK 35 A 105 C 22.8 21 1/2"–1" 1/2"–1" 1/2"–1" on request

DK 47 A 743 CA 40F 1.4027 40 3/8"–1" 3/8"–1" on request

DK 57 AISI 420 F 1.4027 40 3/8"–1" 3/8"–1" on request

Vaposcope VKSightglasses

Pressure ratings up to PN 40

GESTRA VAPOSCOPES allowvisual supervision of flow conditionsin pipelines. These double-sidedsightglasses can be used forchecking heat exchangers and con-densate systems, so that disturb-ances are immediately recognizedand loss of production avoided.

Operation

As the specific gravity of gaseousmedia (steam) is lower than that ofliquids (condensate), the steam willpass over the condensate. This factis used in the Vaposcope to distin-guish between steam and conden-sate. Condensate, steam and airare directed by a rigid deflectorthrough the water seal formed bythe condensate in the Vaposcope.Steam and gas pass over thecondensate and depress the con-densate level. The following condi-tions can be observed in the sight-glass.

Normal service condition:

Perfect operation of steam trap andheating surface. The deflector isimmersed in the water level.The formation of smallbubbles or a slight tur-bulence are effects that can be ignored.

Loss of live steam:

Steam or air passing through theVaposcope depress the level of thecondensate below the deflector. The steam which is invisible fills thespace between deflector and waterlevel. A mixture of water and steammay lead to a strong formation ofbubbles together with tur-bulence. Possible causes forlive steam loss: Contamin-ation or failure of steam traps.

Banking-up of condensate:

The Vaposcope is completely flooded.If the Vaposcope is installed imme-diately downstream of the heat ex-changer it is to be expected that thecondensate is banking up into theheat exchanger. Possible causesfor banking-up of condensate:Start-up of plant, heat ex-changer operates with addi-tional undercooling, changedoperating conditions (e. g.extremely high heat consump-tion), steam trap size not sufficient,blockage or failure of steam trap.

Steam Trap Testing

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Test Set VKE Test set for monitoring steam traps Pressure ratings up to PN 40

The test set VKE is used for moni-toring steam traps to detect leakageof live steam. A separate testchamber fitted with a connection for the conductivity electrode is in-stalled directly upstream of thesteam trap to be monitored. Theelectrode is then either linked withthe hand-held test unit (local testing)or the remote test unit (remotemonitoring). The test set VKE canbe used for steam traps of all typesand makes.

Operation

The electrode signals the states“condensate” or “steam” to themanual test unit NRA 1-2 (measur-ing in situ) or to the remote test unitNRA 1-1 (automatic remote moni-toring). If the steam trap operatescorrectly, condensate flows aroundthe electrode. This condition isindicated by a green LED. In thecase of steam losses across thetrap, the electrode will emerge fromthe condensate and the red LEDlights up. The remote test unit NRA1-1 has 18 channels for continuousmonitoring of up to 18 steam traps.Each channel is provided with a redLED for alarm indication. A singlepotential-free relay contact is usedfor signalling an alarm condition. The test unit is supplied in a case forwall or panel mounting. The manual test unit NRA 1-2 isprovided with a test cable fitted with a jack plug. The cable can beplugged directly into the testchamber or into a wall-mountingconnection box.

21

Connections, DNType Material

Flanged Screwed Socket-weld

VK 14 Cast iron GG-25 15–50 mm (1/2 –2")

VK 16 Forged steel C 22.8 15–50 mm (1/2"–2") 1/2"–2" 1/2"–2"

VKE with test chamber Cast steel GS-C 25 15–50 mm (1/2"–2") 1/2"–2"

VK and VKE at a glance

Manual test unit NRA 1-2

Remote testunit NRA 1-1

VAPOPHONE Ultrasonic Detector VKP-EX

The portable ultrasonic detector is specially designed for detectingsteam loss through steam trapsand stop valves. Classification EEx ib IIC T4, PTB-No. Ex-84/2063.

Live steam leakage is detected by sound in the ultrasonic rangecaused by flowing steam. Themechanical ultrasonic vibrations are detected by the probe and con-verted into electric signals which areamplified in the measuring instru-ment and indicated on a meter. The equipment is intrinsically safeacc. to classification EEx ib IIC T4(Test No. PTB Ex-84/2063) andsuitable for use in explosion-riskareas. Protection: IP 41

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Steam Trap Testing

TRAPtest VKP 30 Faulty steam traps are a majorsource of waste in a steam distribu-tion system. A trap that is blowinglive steam is the worst offender andthe decreased efficiency results inlost production. Systematicallychecking steam traps for loss of livesteam and consequent heat loss istherefore a matter of prime impor-tance. This is easy to do with alltypes and makes of steam traps byusing GESTRA's steam trap moni-toring, recording and evaluationsystem VKP 30, which detects andassesses ultrasonic vibrations trans-mitted through the trap body by livesteam flowing through the trap. Thevisual display of the terminal showsall signals received during the test inthe form of a graph, clearly distin-guishing between a trap workingcorrectly and one passing even verysmall amounts of steam. All testresults obtained by the hand-held

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Hand-heldterminal VKPN 30

Measuring transducer VKPS 30 Service case

terminal can be stored, evaluatedand organized on the PC. TheTRAPtest VKP 30 consists of themeasuring transducer VKPS 30, the portable terminal VKPN 30 andthe corresponding software for data management by PC. It is wellknown that steam losses throughtrap failure, dirt in the steam trap,wrong use of traps or incorrectlyinstalled equipment can easilywaste thousands of euros a year.An optimized steam system istherefore essential and can evennowadays save up to 30 % of theenergy capacity. Call us in for a fullmechanical and electrical serviceinspection of your steam and con-densate system – our team ofengineers are on hand to keep your installation working at peakefficiency, to maximise your main-tenance budget and optimise theoverall plant efficiency.

GESTRA GmbHMünchener Strasse 77, D-28215 Bremen

P.O. Box 105460, D-28054 Bremen

Telephone +49(0)421-3503-0

Telefax +49(0)421-3503-393

E-mail gestra.gmbh@flowserve.com

Internet www.gestra.de

A Unit of Flowserve Corporation

810124-02/403 G · © 2002 · GESTRA GmbH · Bremen · Printed in Germany

With Energy into the Future