Zurn Wilkins ZW209H User manual

Model ZW209H LEAD-FREE*
Pressure Reducing and Pressure Sustaining Valve
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 ZW209H, 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
thorough in checking and inspecting for proper installation
and makeup.
4. Zurn Wilkins valves are designed to operate in both the verti-
cal and horizontal positions. However, it is recommended that
ZW209H 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 inspections, and maintenance.
ZW209H 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 SC1 Opening Speed Control
Z ZPI Valve Position Indicator
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 con-
trols (O or L on ZW209H schematic) it is necessary to back out
the set screw a minimum of 3 turns from initial set point.
5. Turn the relief pilot adjustment screw counterclockwise until
the screw starts to spin freely to lower the relief pressure so the
pressurereducingpilotcanbesetrst.
6. At this point with the upstream shutoff valve partially 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 the Zurn Wilkins PRV pilot can be set to the desired pres-
sure. To adjust the pressure reducing pilot, loosen jam nut on ad-
justment screw and either turn adjustment screw in (to increase
outlet pressure) or out (to decrease outlet pressure). Tighten jam
nut on pilot when the desired setting has been made.
8. To verify proper operation of ZW209H close and open down-
stream shut off valve several times to ensure downstream pres-
sure is stable at set pressure.
9. Next the relief/sustaining pilot must be set at the desired
sustainingpressure.Withwaterstillowingthroughthemain
valveusetheupstreamisolationvalvetothrottlewaterowinto
the ZW209H. Close the upstream isolation valve until the inlet
pressure at the ZW209H is below the desired sustaining set
pressure.
10.WithwaterowingthroughtheZW209Hstarttoturnthe
relief/sustaining pilot adjustment screw clockwise until the valve
starts to modulate and the inlet pressure starts to increase.
Continue turning the adjustment screw clockwise until the inlet
pressure is at the desired set pressure.
11. If the inlet pressure cannot be adjusted lower than the
desired set relief/sustaining pressure then set the relief valve
by turning the adjustment screw clockwise until the spring is
fully compressed. The control valve will close. Next, slowly
turn the adjustment screw counterclockwise until water starts
toowthroughthecontrolvalve.Nowthereliefvalveissetto
the current inlet pressure. Use the table on the next page to set
the relief pressure at a different pressure than the current inlet
pressure. Turn the adjustment screw clockwise to increase set
pressure or counterclockwise to decrease set pressure. Add or
subtract from the current inlet pressure by turning the adjustment
screw the number of turns required to reach the desired set
pressure based on the adjustment table.
START-UP
CAUTION: To prevent personnel injury and damage to equipment
check that downstream venting is adequate prior to start-up
and test procedures. All adjustments under pressure should
be made slowly while under owing conditions. If the main
valve closes too fast it may cause surging in upstream piping.
1. Open isolation valves (2) in the pilot system (see ZW209H
schematic).
2. Then slowly open the upstream shutoff valve only enough to
llmainvalveassemblyandpilotsystem.
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

PROBLEM POSSIBLE CAUSES CORRECTIVE ACTION
1. Sustaining Pressure High / 1. No pressure at valve Inlet 1. Check Inlet pressure
Reduced Outlet Pressure Low 2. Main valve diaphragm assembly inoperative 2. Disassemble, clean, and polish stem, replace defective parts
3. Reducing or Sustaining Pilots are not opening 3. See Pilot Troubleshooting
2. Sustaining Pressure Low / 1. Foreign matter between disc and seat or worn 1. Disassemble the main valve, remove debris, clean parts, and
Reduced Outlet Pressure High disc 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 / Sustaining Pilots remain open 5. See Pilot Troubleshooting
3. Outlet Pressure creeps to High 1. Air in main valve cover and/or tubing 1.Loosentopcoverplugandttingandbleedairoutofthesystem
Pressure / Sustaining or Reduced
Pressure Fluctuates Intermittently
Start-up
*Note: Pressure change per turn is approximate. Use a gauge at the
inlet of control valve to set and check the relief/sustaining pressure.
12. Once pilot is set, tighten the jam nut.
13. To verify proper operation of ZW209H make small adjustments
to the upstream shut off valve several times to ensure upstream
pressure is stable at set pressure.
14. After pilot system has been adjusted and the valve is
properly regulating the main valve opening and closing speed
controls (O or L) can be adjusted as needed.
15. 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 ZW209H 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. In general a closing speed control
on a ZW209H should be at least 3 turns in from the furthest
open position to prevent high pressure surges downstream.
PROBLEM POSSIBLE CAUSES CORRECTIVE ACTION
1. Outlet Pressure Low 1. No spring compression 1. Tighten adjusting screw
2. Damaged spring 2. Disassemble and replace
3. Closed ball valve 3. Open ball valve
4. Sustaining Pilot set too high 4. Turn Sustaining Pilot adjustment screw counterclockwise to lower
set pressure.
2. Outlet Pressure High 1. Mechanical obstruction 1. Disassemble and remove obstruction, replace parts as necessary
2.Worndisc(regulating>10psiofowsetpoint) 2. Disassemble and replace disc
3. Clogged "Wye" Strainer 3. (See plugged “Wye” strainer remedy)
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 2. PRESSURE REDUCING PILOT SYSTEM TROUBLESHOOTING
Relief Pilot
Adjustment
Range
Pressure
Change per Turn
(PSI)*
150-300 28.5
50-200 23
30-90 11.5
10-35 2.8
5-15 2.5
Troubleshooting
PROBLEM POSSIBLE CAUSES CORRECTIVE ACTION
1. Sustaining Pressure High 1. Over compressed spring 1. Loosen adjusting screw
2. Small pilot sensing line clogged 2. Disassemble and clean or replace
3. Closed isolation ball valve 3. Open isolation ball valves
4. Worn diaphragm or stem o-ring 4. Disassemble and replace diaphragm or o-ring
2. Sustaining Pressure Low 1.Insufcientspringcompression 1. Tighten adjusting screw
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
The following troubleshooting information in Tables 1 & 3 deals strictly with the ZW209H valve and pilot systems. It is recommended to
verify that the pilot system is properly functioning before troubleshooting the main valve. All trouble-shooting can be performed without
removing the cover. It is also recommended to permanently install a model ZPI valve position indicator.
TABLE 1. PRESSURE RELIEF/SUSTAINING PILOT SYSTEM TROUBLESHOOTING
TABLE 3. MAIN VALVE 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.
PRESSURE SUSTAINING PILOT CHECK
1. With pressure on the inlet of the ZW209H turn the pressure
sustaining pilot (PV-RLF) adjustment screw clockwise all the
way in.
2.Closetheoutletisolationballvalve.Opendownstreamtting
orconnectionsowatercanowthroughvalve.Valveshould
close after some time. If installed, verify the valve position indi-
cator (model ZPI) is closed.
3.Ifthereiscontinuousow,themainvalveisnotsealingprop-
erly. It is recommended that the main valve be disassembled
and inspected (Refer to “Disassembly” section).
4. Open the outlet isolation ball valve. The inlet pressure must
be less than the maximum adjustment of the relief pilot (PV-
RLF)shownontag.Iftherewasnoowduringtheprevious
step,butthereisnowcontinuousow,thereliefpilotvalveis
not sealing properly. It is recommended that the pilot valve be
disassembled and inspected.
5. Relieve downstream pressure then turn the adjustment
screw on the relief pilot counterclockwise until water starts to
ow.Ifnowaterstartstoowandthereisinletpressure,then
the pilot is not functioning correctly. It is recommended that the
pilot valve be disassembled and inspected.
PRESSURE PILOT REDUCING CHECK
1. With pressure on the inlet of the ZW209H turn the relief pilot
(PV-RLF) adjustment screw counterclockwise until the screw
starts to spin freely to lower the relief pressure set point. Inlet
pressure must be above 10 psi.
2. Slowly close the outlet ball valve in the pilot system. Open
downstreamttingorconnectiontoallowwaterow.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 opening
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 disassembled 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valvepilotby
cracking open a downstream source. There should be continu-
ousow.Ifnot,thepressurereducingpilotvalveisnotopen-
ing properly. It is recommended that the pilot valve be disas-
sembled 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 pressure
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 Reducing Pilot Sys-
tem Troubleshooting, Table 2. Corrective Action section).
7. If the pressure is regulating to the desired system pressures
proceed with diagnosis checks for the main valve.
DIAGNOSIS CHECKS
CAUTION: Do not service valve while under pressure. When
performing diagnosis checks on the ZW209H when the valve
is fully open, high ow rates and high downstream pres-
sures 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
3
ZURN WILKINS
1747 Commerce Way, Paso Robles, CA 93446 Phone:[phone] Fax:[phone]
www.zurn.com
®
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.
ISZW209H (REV. C 3/16)
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
WARNING: This product contains a chemical known to the State of California to cause cancer, birth defects and other reproductive
harm
ADVERTENCIA: Este producto contiene una sustancia química que el Estado de California como causante de cáncer, defectos de
nacimiento y otros daños reproductivos