Zurn Wilkins ZW209Q Manual

Model ZW209Q LEAD-FREE*
Pressure Reducing Valve with Downstream Surge Protection
Globe and Angle Pattern Bodies
1 1/4", 1 1/2", 2", 2-1/2", 3", 4", 6", 8", 10", 12", 14" & 16"
*Contains a weighted average lead content less than 0.25% for wetted surfaces
NOTE: Flushing of all pipe lines is to be performed to remove all
debris prior to installing valve.
NOTE: If installation is subject to very low ow or potentially static
conditions it is recommended a pressure relief valve (1/2" minimum)
be installed downstream of the pressure reducing valve for additional
system protection.
1. For making adjustments and servicing allow for adequate space around
the valve before installing valve.
2. When installing a ZW209Q, gate valves installed on both inlet and outlet
are recommended for maintenance allowing for isolation of valve.
3. Positionthevalveinlinematchingthedirectionofowasindicatedon
thevalvemodeltagwiththeproperdirectionofowinthesystem.Once
attachedtoline,doublecheckallfasteners/boltsinthepilotsystemandon
mainvalvearetightandthereisnodamagepriortopressurizingsystem.
NOTE: Pressure in some applications can be very high so be thor-
ough in checking and inspecting for proper installation and makeup.
4. Zurn Wilkins valves are designed to operate in both the vertical and
horizontal positions. However, it is recommended that ZW209Q 6” and
larger, be installed in the horizontal position. The horizontal positioning
of the larger valves avoids premature wear due to the mass of plunger
assembliesaswellasallowsforgreateraccessibilityduringannualinspec-
tions, and maintenance.
ZW209Q SCHEMATIC
STANDARD COMPONENTS
1 Main Valve
2 850MXL Isolation Valve
3SXL"Wye"TypeStrainer
4 Pressure Gauge
5 Restriction Tube Fitting
6 PRXLPressure Reducing Control
7 PV-RLF Pressure Relief Valve
OPTIONAL FEATURES
C40XL2HydraulicCheckw/
Isolation Valve
L SC1 Closing Speed Control
OSC2OpeningSpeedControl
Z ZPI Valve Position Indicator
1.Openisolationvalves(2)inthepilotsystem(seeZW209Qsche-
matic).
2.Thenslowlyopentheupstreamshutoffvalveonlyenoughtoll
mainvalveassemblyandpilotsystem.Priortopressurizingthevalve
assemblyitisalsorecommendedthataZPIvalvepositionindicatorbe
installedtoaidinverifyingpropervalvemovement.
3.Asthevalveisllingwithwater,itisnecessarytobleedthemainvalve
andpilotsystemofair.Toventair,partiallyopenorloosenthehighest
plugsorttingsinthesystem.TheZPIvalvepositionindicatorisagreat
location,asithasatestcockatthetoptoventairpressure.Itmaybe
necessarytobleedsystemmorethanonce.Afterremovalofairinthe
systemtightenallloosettings.NOTE: If valve is installed vertically, it
will be necessary to loosen some upper cover bolts until you have
vented all the air from the cover chamber.
4.Beforesettingvalve,ifvalveisequippedwithSC1Flowcontrols(O
orLonZW209Qschematic)itisnecessarytocompletelybackoutthe
set screw.
5.Turnthesurgeprotectionpilot(reliefpilot)adjustmentscrewclock-
wiseuntilthepilotspringiscompressedcompletelysothepressure
reducingpilotcanbesetrst.
6.Atthispointwiththeupstreamshutoffvalveopen,slowlyopenthe
downstream shut off valve. Flow will begin to occur and pressure should
buildupinvalveandeventuallystabilize.
7.Nextitisadvisabletoowwaterthroughthevalvetoensureallair
hasescapedfromsystem.Withwaterowingthroughthevalve,setthe
pressure reducing pilot 10 to 15 psi higher than the desired pressure
reducing set pressure so the surge protection pilot can be set. To adjust
the pressure reducing pilot, loosen jam nut on adjustment screw and
eitherturnadjustmentscrewin(toincreaseoutletpressure)orout(to
decreaseoutletpressure).
8.Nowsetthesurgeprotectionpilot.Withwaterstillowingthrough
the main valve, start to turn the surge protection pilot adjustment screw
counterclockwise until the downstream pressure drops 5 to 10 psi.
Tighten the jam nut on the surge protection pilot.
9.Lowerthedownstreampressuretothedesiredsettingbyadjusting
pressurereducingpilot.Oncepilotisset,tightenthejamnut.
10.ToverifyproperoperationofZW209Qcloseandopendownstream
shut off valve several times to ensure downstream pressure is stable at
set pressure.
11.Afterpilotsystemhasbeenadjustedandthevalveisproperlyregu-
lating,themainvalveopeningandclosingspeedcontrols(OorL)can
be adjusted as needed.
12. When setting speed controls, turning the adjustment screw into the
speedcontrolwillrestricttheamountofowthroughtheneedlevalve.
Dependingonwhetherthecontrolisforopeningorclosing(referto
ZW209Qschematic)thecontrolwilleitherslowtheopeningorclosing
of the main valve when the adjustment screw is turned into the speed
control. Adjust as needed and tighten jam nut.
START-UP
CAUTION: Topreventpersonnelinjuryanddamagetoequipmentcheck
that downstream venting is adequate prior to start-up and test proce-
dures. All adjustments under pressure should be made slowly while
under owing conditions.
Installation / Start-up
ZURN WILKINS
1747 Commerce Way, Paso Robles, CA 93446 Phone:[phone] Fax:[phone]
www.zurn.com
®
®
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Installation Troubleshooting Maintenance Instructions
!WARNING: Cancer and Reproductive Harm - www.P65Warnings.ca.gov
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PROBLEM POSSIBLE CAUSES CORRECTIVE ACTION
1. Main Valve fails to open 1. No pressure at valve Inlet 1. Check Inlet pressure
2.Mainvalvediaphragmassemblyinoperative 2. Disassemble, clean, and polish stem, replace defective parts
3. Reducing or Relief Pilots are not opening 3. See Pilot Troubleshooting
2. Main Valve fails to close 1. Foreign matter between disc and seat or 1. Disassemble the main valve, remove debris, clean parts,
worn disc and replaced defective parts
2. Scale on stem or diaphragm ruptured 2. Clean parts, and replace defective parts
3."Wye"Strainerplugged 3. Remove, clean, and/or replace
4.38-850XL(ballvalves)closed 4.Openballvalves
5. Reducing or Relief Pilots remain open 5. See Pilot Troubleshooting
3. Fails to Regulate 1. Air in main valve cover and/or tubing 1.Loosentopcoverplugandttingandbleedairoutofthe
system
PROBLEM POSSIBLE CAUSES CORRECTIVE ACTION
1.OutletPressureLow 1. No spring compression in Pilot 1. Tighten adjusting screw
2. Damaged spring in Pilot 2. Disassemble and replace
3.Clogged"Wye"Strainer 3. Remove, clean, and/ or replace
4. Closed ball valve 4.Openballvalve
5. Relief Pilot set too low 5. Turn Relief Pilot adjustment screw clockwise to raise
set pressure.
2. Fails to Regulate 1. Mechanical obstruction 1.Disassembleandremoveobstruction,replacepartsasnecessary
(OutletPressureHigh) 2.Worndisc(regulating>10psiofowsetpoint) 2. Disassemble and replace disc
3. Pressure gauge fails to operate 1. Damage pressure gauge 1. Replace pressure gauge
2. Closed ball valve 2.Openballvalve
When performing troubleshooting and diagnosis checks it is recommended that the following steps be performed in sequential order
for best results.
TABLE 1. PRESSURE REDUCING PILOT SYSTEM TROUBLESHOOTING
Troubleshooting
TABLE 3. MAIN VALVE TROUBLESHOOTING
2ZURN WILKINS
1747 Commerce Way, Paso Robles, CA 93446 Phone:[phone] Fax:[phone]
www.zurn.com
®
ThefollowingtroubleshootinginformationinTables1-3dealsstrictlywiththeZW209Qvalveandpilotsystems.Itisrecommended
toverifythatthepilotsystemisproperlyfunctioningbeforetroubleshootingthemainvalve.Alltroubleshootingcanbeperformed
withoutremovingthecover.ItisalsorecommendedtopermanentlyinstallamodelZPIvalvepositionindicator.
PROBLEM POSSIBLE CAUSES CORRECTIVE ACTION
1. Downstream pressure going
high / Control valve not closing
1.Overcompressedspring 1. Loosen adjusting screw / Repeat start-up procedure
2. Small pilot sense line clogged 2. Disassemble and clean or replace
quickly 3. Closed isolation ball valve 3.Openisolationballvalve
4. Worn diaphragm or stem o-ring 4. Disassemble and replace diaphragm or o-ring
2. Low downstream pressure / 1.Insufcientspringcompression 1. Tighten adjusting screw / Repeat start-up procedure
Control valve not opening 2. Damaged spring 2.Disassembleandreplacepartsasnecessary
3. Worn seat seal or seat 3. Disassemble and replace seat seal or seat
4.Obstructiononseat 4. Disassemble and remove obstruction
5.Obstructionarounddiaphragm 5. Disassemble and remove obstruction
6. Worn seat o-ring 6. Disassemble and replace as needed
TABLE 2. PRESSURE RELIEF/SURGE PROTECTION PILOT SYSTEM TROUBLESHOOTING

Troubleshooting
PILOT SYSTEM FUNCTION CHECK
CAUTION: To prevent personnel injury and damage to
equipment check that downstream venting is adequate
prior to start-up and test procedures.
SURGE PROTECTION PILOT CHECK
1.Withwaterowingthroughthemainvalveturnthesurgepro-
tectionpilot(PV-RLF)adjustmentscrewclockwiseallthewayin.
2.Whileowingcloseandopenthecoverisolationballvalve
on the surge protection pilot while watching downstream
pressure. If downstream pressure changes when opening
and closing the cover isolation ball valve the pilot valve is not
sealingproperly.Itisrecommendedthatthepilotvalvebe
disassembled and inspected.
3. Close the outlet isolation ball valve on the pressure reduc-
ing pilot. The main valve should close, after sometime. If
installed,verifythevalvepositionindicator(modelZPI)is
closed.
4.Ifthereiscontinuousowfromtheoutletofthemainvalve,
themainvalveisnotsealingproperly.Itisrecommended
thatthemainvalvebedisassembledandinspected(Referto
“Disassembly”section).
5.Opentheoutletisolationballvalveonthepressurereduc-
ing pilot. The outlet pressure must be lower than the inlet
pressureandwatermustbeowingthroughthemainvalve
for the next steps 6-7.
6. Close all three isolation ball valves connected to the pres-
surereducingpilot.Closethecoverisolationvalverst,then
the other two valves.
7. With all three surge protection isolation ball valves open,
slowlyturnthesurgeprotectionadjustmentscrewcounter-
clockwise until the outlet pressure starts to drop.
8. If the downstream pressure does not start to drop, the pilot
valveisnotopeningproperly.Itisrecommendedthatthe
surge pilot valve be disassembled and inspected.
PRESSURE PILOT REDUCING CHECK
1. With pressure on the inlet of the ZW209Q close the 3 iso-
lation ball valves connecting to the surge protection pilot.
2.Whileowingwaterslowlyclosetheoutletballvalveinthe
pressurereducingpilotsystem.Allowthecovertopressurize
andthemainvalvetoclose.Ifinstalled,verifythevalveposition
indicator(modelZPI)isinaclosedposition.
3. Close the cover ball valve to keep the main valve closed.
4.Proceedwithventingoutletdownstreampressurebyopen-
ing a source downstream. When opening the downstream
sourceifthereiscontinuousow,themainvalveisnotsealing
properly.Itisrecommendedthatthemainvalvebedisassem-
bledandinspected(Referto“Disassembly”section).
5. With the main valve closed, open outlet isolation valve
andallowasmallamountofwatertoowthroughthepilot
valvebycrackingopenadownstreamtting.Thereshouldbe
continuousow.Ifnot,thepressurereducingpilotvalveisnot
openingproperly.Itisrecommendedthatthepilotvalvebe
disassembledandinspected(Refertoappropriatepressure
reducingpilotvalveinstructionsheet).
6. Monitor outlet pressure while cracking open and closing the
downstreamshutoffvalveandcomparetothedesiredsystem
settings. If the outlet pressure is the same as the inlet pres-
sureorclimbsmorethan15psiabovetheowingreduced
pressuresetpoint,thepressurereducingpilotisnotproperly
regulating(refertothepilottroubleshootingPressureReduc-
ingPilotSystemTroubleshooting,Table2.CorrectiveAction
section).
7.Ifthepressureisregulatingtothedesiredsystempres-
sures proceed with diagnosis checks for the main valve.
DIAGNOSIS CHECKS
CAUTION: Do not service valve while under pressure.
When performing diagnosis checks on the ZW209Q when
the valve is fully open, high ow rates and high down-
stream pressures can occur.
DIAPHRAGM CHECK
1.Slowlycloseupstreamshutoffvalveandrelieveallpressure
downstream.
2. With all pressure relieved in the main valve, close both inlet
and outlet isolation valves and remove side plug on cover and
leave off.
3.Thenopenupstreamshutoffvalvepartially,allowingwater
toowthroughthevalve.Whileowingwatermonitortheopen-
ingonthecover.Ifuidbeginstoowoutoftheopenholein
thecover,thenthereismostlikelydamagetothediaphragm
oruidisleakingpastthediaphragmassemblyduetoloose
assembly.Itisrecommendedthatthevalvecoverberemoved
toinvestigatetheleakage(Toremovecoversee“Maintenance”
sectionforprocedures).Ifnowaterowsoutofcoverthenthe
diaphragmisgoodandyoumayproceedtothediaphragm
movement check.
DIAPHRAGM MOVEMENT CHECK
1. The diaphragm movement check can be determined during
the diaphragm check or it can also be performed with the use of
a valve position indicator model ZPI.
2. Replace cover plug and open pilot ball valves on inlet and cover.
3.Closingtheoutletisolationballvalveswilldirecttheowto
the cover causing it to close. NOTE: Slow or delayed closing
of main valve is normal and is due to the time requirements
to ll, pressurize cover, and stretch the diaphragm into the
closed position. This normal delay is not mechanical bind-
ing of the valve assembly.
4. Using the valve position indicator, make note of the closed
position on the indicator. Compare distance of the open mark to
the close mark and compare to Table 3.
5.Verifythatthemainvalveisclosed,byopeningadown-
streamsource(nottheoutletisolationballvalveonthemain
body).Ifwatercontinuouslyows,thenthemainvalveisnot
sealingproperly.Doublecheckthevalvemovementmatches
thevaluesinTable3andrefertothedisassemblyprocedures
section if it does not. This is an indication that the main valve is
not sealing due to an obstruction between the seat and the seal
oradamagedseal.Ifwaterdoesstopowingandthemeasured
valve movement does not match Table 3, then there is possible
damageunderthecover.Removecovertoidentifyobstruction
andreplacepartsasnecessary.
TABLE 3. VALVE STEM TRAVEL
VALVE SIZE
(in)
VALVE SIZE
(mm)
STEM TRAVEL
(in)
STEM TRAVEL
(mm)
1-1/4" - 1-1/2" 38 0.4 10.2
2" 50 0.7 18.0
2-1/2" 65 0.8 21.3
3" 80 0.9 23.4
4" 100 1.1 28.8
6" 150 1.7 43.4
8" 200 2.4 59.7
10" 250 2.8 71.1
12" 300 3.4 86.4
14" 350 3.8 96.5
16" 400 4.3 109.2

6.Forsmallervalves(6”andbelow)diaphragmcheckscanbe
performedbyhandwiththeuseofavalvestemtool.Thevalve
stem tool can be made using Table 4 to create a “T” bar handle
with the appropriate threads on the opposite end of the “T” handle.
TABLE 4. VALVE STEM THREAD SIZE
rstremoveallpressureinthesystemandventthecover.
Then remove the center plug on the cover and insert tool into
thetopofthestemthreads.Oncethetoolisinserted,the
valve can be lifted up and the valve movement can be mea-
suredbycreatingmarksonthetoolintheopenedandclosed
positions. The distance between marks is the valve stem
travel.Replaceorrepairanypartsasnecessary.
SEAL CHECK
1. To check the seal of the valve disc, an additional pressure
gauge will be needed downstream of main valve.
2.Withthevalveowing,slowly,closepilotoutletballvalves
toapplypressuretocoverandallowtoclose.
3.Opendownstreamsourceandmonitorthepressureonthe
inlet and installed outlet gauge, for one min. The pressure on
the outlet side should remain zero. If the pressure matches inlet
pressure or increases, the main valve is leaking or the outlet
ballvalveonthepilotsystemisallowingpressuretocreepby.
Eitherwayitisrecommendedthatthevalvebedisassembled
andinspected(referto“Disassembly”section).
Troubleshooting
Maintenance Instructions
PREVENTATIVE MAINTENANCE
The Zurn Wilkins ZW200 models require minimal maintenance.
However,itishighlyrecommendedtoscheduleannualinspec-
tions and to have a repair kit on hand before work begins.
DISASSEMBLY
Warning: Because of the ability to perform inspections and
maintenance without removal from the system, it is very
important that all shut off valves be closed and all pressure
relieved in the valve before beginning disassembly. Failure
to do so can result in personnel injury or equipment damage.
1.Verifythatallpressuresourcesareclosedupanddown-
stream of valve.
2.Removepressureinpilotsystembylooseningthetubet-
tingstothevalvebodyandcover.Whenallpressurehasbeen
vented, continue to disassemble the pilot control valve and
cover tubing. NOTE: Taking a picture before tear down can help
withre-assemblyofpilotsystem.
3.Nextremovethecoverbylooseningandremovingthe
coverbolts.Ifthecoverdoesnotcomeoffeasilyitmaybenec-
essarytoloosenthecoverusingabrasschiselandrubbermal-
let.Applythechiselunderthecoverpointingupwardawayfrom
valvebodyandtapbottomofcoverwiththechiselandmalletto
loosenthecover.Oncethecoverisloose,pullcoverstraightup
toavoiddamagingthestemandstembearinginthecover.On
largervalves8”andup,eyeboltsandahoistarerecommended
due to the weight of these larger covers.
4.Withthecoverremovedthediaphragmassemblycanbe
removed. To avoid damaging the seat bushing, grab the stem
and lift straight up. For larger valves 8” and up it is recommended
thataneyeboltwiththeproperstemthreadsbeusedwitha
hoisttolifttheassemblyoutofthevalve(seeTable4forap-
propriatestemthreads).
5.Nextitisrecommendedthatthediaphragmassemblybe
placedinavisewiththebottomhexnutsecured.Oncesecured
remove the spring and stem nut. While removing the nut inspect
the stem threads. Clean stem with a wire brush if mineral de-
posits or corrosion are present.
6. After inspecting the stem and removing the nut the diaphragm
assemblycanbedismantled.Ifthevalvehasnotbeenserviced
inawhileitispossiblethattheassemblywillrequiretheuseofa
rubbermalletorprybarstodismantletheassembly.Ifthisisthe
casegentlytaporprythecomponentsuntilthecomponentsare
free to move. When disassembling be sure to clean, inspect, and
saveallcomponents.Replaceanydamagedcomponentsas
necessary.
7.Thelastcomponenttoinspectistheseatwhichisinthebody
of the main valve. During inspection of the seat, clean and polish
asnecessarywithnegritwet/drysandpaper(400gritorhigher).
Typically,ifaftercleaningthereisnovisualdamageorexcessive
wear the seat should not require removal. If damage is present
ortheseatisexcessivelyworntheseatshouldbereplaced.
8. To remove the seat, on valves 6” and smaller the seat is
threadedintothebodyandwillrequireaseatremovaltool.Care
should be taken when removing the seat to avoid damaging.
On8”andlargervalves,theseatisheldinplacewithathead
hexscrews.Forlargervalvesaseatpullermayberequiredto
removetheseatfromthebody.
INSPECTION OF COMPONENTS
Cleaning of components is required for proper inspection. Lime
depositsarecommoninsystemsthatusewater.Toremove
deposits,negritwet/drysandpaper(400gritorhigher)canbe
used. If deposits cannot be removed, off the shelf lime deposit
remover can be used. Prepare a solution following the lime
depositremoverinstructionsandsoakcomponents(excluding
rubbercomponents)untillimedepositsareremoved.
CAUTION: When handling chemicals (acids) be sure to use
proper safety equipment (gloves and eye protection) and
practices. After soaking components, be sure to thorough-
ly rinse all components before handling and re-assembling
valve.
Onceallvalvecomponentshavebeencleaned,inspecteach
component looking for damage, abnormal wear & corrosion,
and replace all components that look questionable. Replace all
rubber components including the diaphragm, o-rings and disc
eachtimethevaleisservicedorinspected(rubbercomponents
are standard in ZW200 repair kits.
4ZURN WILKINS
1747 Commerce Way, Paso Robles, CA 93446 Phone:[phone] Fax:[phone]
www.zurn.com
®
7. To perform the diaphragm check using the vale stem tool,
VALVESIZE(in) THREAD SIZE UNF INTERNAL
1-1/4" - 1-1/2" 10-32
2" 10 - 32
2-1/2" 10 - 32
3" 1/4 - 20
4" 1/4 - 20
6" 1/4 - 20
8" 3/8 -16
10" 3/8-16
12" 3/8-16
14" 3/8-16
16" 3/8-16

5
ZURN WILKINS
1747 Commerce Way, Paso Robles, CA 93446 Phone:[phone] Fax:[phone]
www.zurn.com
®
Maintenance Instructions
REASSEMBLY
1.Firstreinstallseatintobody.Besuretouselubearound
seat o-ring before tightening. Tighten seat according to torque
values in Table 5 using seat tool.
2. Next place valve stem in a vise clamping on the hex portion
ofthestem.Thenassemblethediaphragmassemblyasshown
in Figure to the right. When assembling be sure that the dia-
phragm is centered on the raised step of the disc retainer. It is
alsorecommendedtoapplylubetostemthreadsando-rings
before tightening. Then tighten the stem nut according to Table
5 for torque values.
3.Lowerdiaphragmassemblycarefullyintotheseatbushing
Be careful not to damage the seat or stem while installing as-
sembly.Rotatetheassemblyasneededuntiltheboltholeson
thediaphragmlineupwiththebodyboltholes.
4. Place lower spring disc on the diaphragm disc and place
springontopoftheassembly.Theninstallcover,aligning
the bolt holes and insuring that the cover is not pinching the
diaphragm between the bolt holes. Position cover so plug holes
are in original position.
5. Install cover bolts and tighten in a star pattern to the torque
values in Table 5.
6.Beforeinstallingcentercoverplugmanuallycheckthat
assemblyhasfulloperatingtravelbeforeinstallingthepilot
assembly(referto“DiaphragmMovement”inthediagnosis
checkssection).
7.Oncefulloperationrangeofthemainvalveisveried,
beginreinstallingpilotsystem.
8.Afterinstallingpilotsystemdoublecheckthatallplugs,
bolts,andttingsaresealedandtightbeforeapplyingpressure.
9.Slowlyopenupstreamisolationvalvetopressurizethe
systemandcheckforanyleaks.
10. Stop leaks as needed and proceed to “Start-Up” and “Di-
agnosisCheck”sectionsforreturningvalvetopropersystem
operations.
TABLE 5. VALVE TORQUE SETTINGS
COVER CENTER PLUG
COVER BOLTS
COVER NUTS (8" AND LARGER)
COVER PLUG
COVER
COVER BEARING (STEM GUIDE)
UPPER SPRING DISC (4" AND LARGER) * †
SPRING †
LOWER SPRING DISC (4" AND LARGER) * †
STEM NUT
STEM WASHER
DIAPHRAGM WASHER
(DIAPHRAGM DISC)
DIAPHRAGM*
UPPER STEM O-RING*
DISC RETAINER
(PLUNGER)
LOWER STEM O-RING*
DISC (SEAL RING)*
DISC GUIDE
(SEAL RING RETAINER)
STEM
SEAT SCREWS (8" AND LARGER) ‡
SEAT ‡
COVER STUDS (8" AND LARGER)
SEAT O-RING ‡
BODY
BODY PLUGS
STEM ASSEMBLY †
* RUBBER REPAIR KIT ITEMS
† COMPLETE REPAIR KIT ITEMS
‡ SEAT REPAIR KIT
VALVE
SIZE
(in)
COVER
(ft-lbs)
DIAPHRAGM
ASSEMBLY
(ft-lbs)
THREADED
SEAT
(ft-lbs)
SEAT
BOLTS
(ft-lbs)
1-1/4" 3.5 7.5 11 N/A
1-1/2" 3.5 7.5 11 N/A
2" 15 20-25 30 N/A
2-1/2" 25 25-35 60 N/A
3" 25 35-45 70 N/A
4" 55 40-50 85 N/A
6" 110 50-60 95 N/A
8" 120 60-70 N/A 7.4
10" 184 70-75 N/A 7.4
12" 200 110-115 N/A 7.4
14" 275 170-175 N/A 7.4
16" 360 230-240 N/A 7.4

ThePV-RLFPressureReliefValvemaybeinstalledinany
position.Theowdirectionisshownbelow.Flowgoesfromthe
narrowsidetothewidesideofthecastbody.
Disassembly
Priortodisassembly,relieveallpressureinpilotsystemand
then remove the PV-RLF.
1.Securevalvebodyandturntheadjustmentscrewallthe
wayout.
2. Next remove 8 socket head screws around the pilot bell
usinga5/32”hexkey.Removethebell,thespring,and2
spring discs.
3. Remove the spacer and remove small gasket from the
bottom of the spacer. Use a 12mm socket or adjustable
wrench on the diaphragm and plunger nuts to disassemble
theplunger/diaphragmassembly.Unscrewoneendofthe
stem.
4.Atthispointslidetheplunger/diaphragmassembly
out of the valve spacer.
5. Use soft jaws or a towel and pliers to clamp the stem.
Be careful not to scratch the stem as this is an o-ring
surface. Use an adjustable wrench on the opposite nut
toremovetheremainingplunger/diaphragmassembly.
6. The parts removed from the disassembled diaphragm
andplungerassemblyareaplunger,smallwasher,2
o-rings , 2 nuts, a medium washer, a large washer,
diaphragm, and lock washer.
7.Useasmallpinornailtocarefullyremovetheo-ring
on the inside through hole of the spacer.
8.Aftercompletedisassemblythoroughlycleanand
inspectallcomponentsbeforereassembly.Replace
partsasnecessaryafterinspection.
9.Thepilotseatgenerallydoesnotneedtoberemoved,
but if after inspection it requires replacement it can be
removed with a 1-1/16” socket.
PV-RLF Valve
Reassembly
ReassemblyofthePV-RLFisthereverseofdisassembly.
1.Carefullyinstallanewo-ringinthethroughholeof
the spacer.
2.Placethemediumwasher(withroundouteredge
towardthediaphragm)onthesideofthestemwith
the chamfered tip.
3.Followthewasherbyputtingonanewo-ring,new
diaphragm,largewasher(withtheinnerstepagainstthe
diaphragm),lockwasher,and5/16”(chamferedside
awayfromdiaphragm)nutthenhandtighten.
4. Slide the stem through the spacer with the diaphragm
assemblyonthespacersidewithacirculargrooveon
the top surface.
5.Ontheothersideofthestemplacethesmallwasher,
o-ring,plunger(withtherubberfacingawayfromthe
spacer),andnut.
DIRECTION
OF
FLOW
INLET OUTLET
ITEM DESCRIPTION
11/2"ReliefBody
2O-ringBunaNitrile,NSFListed
3ReliefPlungerAssy.
4DiaphragmO-ring
55/16" Flat Washer
6Relief Pilot Stem
7O-ring,BunaNitrile,NSFListed
85/16" Internal Tooth Lock Washer
9Spring Disc
10 Spring
11 Pilot Bell
12 3x8-16 Jam Hex Nut
ITEM DESCRIPTION
13 3/8-16 Adjustment Bolt
14 Adjustment Cover
15 5/16-18 Diaphragm Nut
16 Relief Pilot Upper Diaphragm Disc,SS
17 10-32 X 1-1/2" Skt Hd Cap Screw, SS
18 Tag
19 Diaphragm
20 Relief Pilot Lower Diaphragm Washer
21 Relief Pilot Spacer
22 Sensing Hole Gasket
23 O-ring,BunaNitrile,NSFListed
24 Relief Pilot Seat
Maintenance (PV-RLF Valve)
6. Use adjustable wrenches to tighten the plunger and
diaphragm nuts.
7. Place small gasket on bottom of valve spacer.
8.Installtheplungerassemblyontothebodywiththeplunger
sitting on the valve seat. The small rubber gasket on the
plunger side of the spacer must cover the sensing hole on
thepilotbody.
9. Place a spring disk on the stem, then the spring, another
spring disk and bell.
10. Insert socket head cap screws into pilot bell holes and
threadintovalvebody.Placemodeltagonthefourscrews
thatstraddlethebodyinlet.Tightenallscrewsinacross 
pattern.
11.Installadjustingscrewbyhandwithjamnut.Setvalveonce
reinstalledintopilotrysystem.Referto"Start-up"sectionon
page one for proper setting of relief pilot. For further assis-
tance or ordering replacement parts go to www.zurn.com
or call product support 877-222-5356.
Table 1
13
11
10
17
20
7
21
6
23
3
24
2
15
1
5
4
18
12
4
19
16
22
9
15
8
14
9
6ZURN WILKINS
1747 Commerce Way, Paso Robles, CA 93446 Phone:[phone] Fax:[phone]
www.zurn.com
®

*Notes for Body Minimum Friction Loss Chart:
Minimuminletpressureis10psihigherthansetpointortheadditionalbodyfrictionlossatintendedow,whicheverishigher.(fric-
tionlossmaybeimportantatowsabove20ft/s)
Example:A6”valveintendedtoow2000GPMat150psihasafrictionlossof20psiat2000GPM.Theminimuminletpressure
would be 150 + 20 = 170 psi. When inlet pressure is below set point, the outlet pressure will be the pressure at the inlet minus the
friction loss.
ISZW209Q(REV.C6/17)
FLOW CHARACTERISTICS
7
ZURN WILKINS
1747 Commerce Way, Paso Robles, CA 93446 Phone:[phone] Fax:[phone]
www.zurn.com
®
PRESSURE REDUCTION LIMIT
0
50
100
150
200
250
300
020 40 60 80 100 120
OUTLET PRESSURE (PSI)
INLET PRESSURE (PSI)
Safe
operating zone
Noise
zone
Damage Zone Noise Limit
Cavitation damage
zone(intermittent
operationallowed)
0
1
10
100
10 100 1000 10000
PRESSURE DROP (PSI)
FLOW (GPM)
BODY MINIMUM FRICTION LOSS
1-1/4" Globe & Angle
1-1/2" Angle
1-1/2" Globe
2" Globe
2" Angle
2-1/2" Globe
2-1/2" Angle
3" Angle
4" Globe & Angle
6" Angle
8" Angle
6" Globe
8" Globe
3" Globe
10" Angle
10" Globe 12" Globe
14" Globe
16" Globe