Zurn Wilkins ZW205FP Installation manual

1
INSTALLATION
NOTE: Prior to installation of the ZW205FP, ensure that all debris is
ushed out the piping system before installed.
1. During the installation of a ZW205FP in a sprinkler system, Underwriter
Laboratories (UL) requires NFPA 13 “Standard for Installation of Sprinkler
Systems” and NFPA 20 "Standard for the Installation of Stationary Pumps
for Fire Protection" be followed.
2. Upon installation UL also requires that the ZW205FP be tested in
accordance with NFPA 13 or NFPA 20. Thereafter the valve shall be in-
spected, tested, and maintained in accordance to NFPA 25 “Standard for
the Inspection, Testing, and Maintenance of Water-Based Fire Protection
Systems”.
3. For making adjustments and servicing allow for adequate space
around the valve.
4. PositiontheZW205FPinlinematchingthedirectionofowasindi-
cated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.
6. Zurn Wilkins valves are designed to operate in both the vertical and
horizontal positions. However, it is recommended that ZW205FP’s 6” and
larger, be installation in the horizontal position.
The horizontal positioning of the larger valves avoids premature wear due to
mass of plunger assemblies as well as allows for greater accessibility during
annual inspections, and maintenance.
Installation  Start-up  Maintenance Instructions
Model ZW205FP
Fire Pump Relief Valve
Globe and Angle Pattern Bodies
2", 2-1/2", 3", 4", 6", 8", & 10"
ZW205FP
Class 150 Flanged
Max 250 psi Inlet
ZW205FPG
Grooved
Max 300 psi Inlet
ZW205FPY
Class 300 Flanged
Max 300 psi Inlet
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. If the main valve opens or closes
too fast it may cause surging in upstream piping.
1. 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. Pressurize the upstream side of the ZW205FP.
2. 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 high-
est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.
3. One can adjust the set pressure of the control valve by one of three
different procedures. Choose one based on the capabilities of the re
protection system
a. Close all discharge lines from the re pump so all ow goes
through the ZW205FP. Loosen the pilot adjustment screw all the way
tolowerthesetreliefpressure.Turnontherepumptopressurizethe
upstream side of the ZW205FP. Note: The control valve should open
and allow a lot of water to ow. If there is no ow, continue turning
the pilot adjustment screw counterclockwise.Oncewaterisowing
through the control valve, slowly turn the pilot valve adjustment screw
clockwise. As the screw is tightened the control valve will slowly start to
close causing upstream pressure to increase. Continue turning adjust-
ment screw clockwise until upstream pressure is stable at the desired
relief set pressure.
Installation / Start-up
DESCRIPTION
The Zurn Wilkins Model ZW205FP Fire Pump Pressure Relief Valve
isdesignedspecicallyforFireSuppressionSystemstorelievehigh
system pressures. The pilot assembly reacts quickly to increases
of upstream pressure to prevent damage to system piping, valves,
andsprinklerswhilemaintainingpositivepressureonrepumps.As
thewaterdemandincreasesintheresuppressionsystemtherelief
valvewillstarttoclose,directingmorewatertosuppressres.The
relief valve will maintain the upstream pressure at the set pressure as
longasmaximumowratesofthevalvearenotexceeded.TheZurn
Wilkins Model ZW205FP is design to open quickly and close slowly to
prevent upstream pressure surges. In addition the Model ZW205FP
comes standard with red epoxy coating internally and externally for
corrosion protection, as well an inlet pressure gauge for quick and easy
maintenance or repair. The ZW205FP is available in both globe and
angle pattern bodies.
ZW205FPTH
Threaded
Max 300 psi Inlet
®
ZURN WILKINS
1747 Commerce Way, Paso Robles, CA 93446 Phone:[phone] Fax:[phone]
®
www.zurn.com
LISTED
FM
APPROVED
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Installation / Start-up
2
b. Turn the pilot adjustment screw clockwise until the spring is
completely compressed. Do not over tighten to prevent damag-
ing the valve. Pressurize upstream of the ZW205FP to desired
relief pressure. Set the relief pressure by slowly turning the
adjustmentscrewcounterclockwiseuntilwaterstartstoow
through the ACV, then turn the adjustment screw 1/8 turn clock-
wise. Now the relief valve is set to the current inlet pressure.
c. If the desired relief set pressure is different than current up-
stream pressure complete step “a” or “b” with current upstream
pressure. Use the table below to set the relief pressure to de-
sired setting. 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 adjust-
ment screw the number of turns required to reach the desired
set pressure based on the adjustment table.
VALVE
SIZE
inches 2 2-1/2 3 4 6 8 10
mm 50 65 80 100 150 200 250
MAX. FLOW RATE (GPM) 260 375 600 1000 2500 5000 7300
ZW205FP SCHEMATIC
STANDARD COMPONENTS
1. Main Valve
2. SXL "Wye"
3. Pressure Gauge
4. Restriction Tube Fitting
5. PV-RLF Pressure Relief Valve
The Zurn Wilkins ZW205FP utilizes a pressure relief pilot valve that installs on the discharge side of the control circuitry. The pilot
Model PV-RLF is a direct acting, normally closed, spring loaded, diaphragm actuated valve. The operation of the ZW205FP begins
withaccuratelysizingthevalve,thennetuningthecontrolcircuitrybyadjustingthePV-RLFtoopenatthedesiredupstream
pressure. Inlet pressure is piped to the inlet of the PV-RLF. A sensing line runs externally from the inlet side of the ACV to the pilot
control chamber under the diaphragm. Thus, inlet pressure exceeding the preset of the pilot acts to open the pilot valve while the
adjustable spring in the pilot seeks to keep it closed. The result is a modulating action in the pilot that is transmitted to the cover of
the main valve. This creates a mirror modulation of the diaphragm assembly in the main valve. Upstream pressure is maintained
withinnarrowlimitsregardlessofchangingowratesoroutletpressure.
Drip Tight Closing Operation
With the use of a three way pilot control, inlet
pressure is directed to the cover where the
pressure forces the valve closed.
Full Open Operation
Using a three way pilot control, pressure is
vented to the outlet from the cover chamber
which enables the inlet pressure to open the
main valve.
Modulating Action
Utilizing a Wilkins modulating control sys-
tem, pressure changes to the cover can be
controlled, allowing the valve to throttle and
compensate for changes.
Operation
Relief Pilot
Adjustment Range
Pressure Change per
Turn (PSI)*
50 - 200 23
150 - 300 28.5
4. Tighten adjustment screw jam nut once step 3 is completed.
To verify proper operation of the ZW205FP, view the valve
during normal operation and check the valve for relief settings.
Adjustments can be made at anytime.
ZURN WILKINS
1747 Commerce Way, Paso Robles, CA 93446 Phone:[phone] Fax:[phone]
®
www.zurn.com

3
2C4
Z
C
1
FLOW
*Note: Pressure change per turn is approximate. Use a
gauge at the inlet of ACV to set / check relief.
Table 1

3
Maintenance Instructions
Flow Characteristics
MAINTENANCE (Main Valve)
InadditiontocomplyingwithNFPA25everyveyears,sched-
uled preventative maintenance and inspection is highly recom-
mended. ZURN WILKINS recommends annual inspection of
valves for leaks and proper operation. It is also recommended
that a repair kit with a new diaphragm, disc, and o-rings be on
hand before work begins.
DISASSEMBLY
Warning: With the ability to perform inspections and mainte-
nance 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. With all pressure removed from the valve, begin slowly
removingarettinginthepilotsystemuntilresidualpressure
is removed from cover. After excess pressure has been relieved
begin removal of pilot tubing to cover.
2. Begin loosening cover bolts and remove cover lifting up to
slide cover bushing off plunger shaft. For valves larger than 6”
it is recommended that lifting lugs and a hoist be used due to
excessive weight of the larger covers.
3. Once the cover is removed the plunger spring and spring
washer can be removed. Then remove the diaphragm assem-
bly by grabbing the stem or lifting from two sides of the dia-
phragm. Be sure to lift straight up to avoid binding the stem in
the seat bushing, as damage can occur. NOTE: Again with the
larger size valves 6” and up it is recommended that a lifting lug
and hoist be used to remove larger plunger assemblies.
4. Place diaphragm assembly in a vise with the bottom hex
secured. Remove the stem nut and inspect threads for dam-
age, corrosion, or pitting.
5. After inspecting the stem and removing the nut the diaphragm
assembly can be dismantled. When disassembling be sure to
clean, inspect, and save all components. Replace any damaged
components as necessary.
6. Next, clean and inspect the seat inside the main valve
body.Ifexcessivewaterdepositsarepresent,negritsandpa-
per can be used to clean. The seat is designed to be removed,
but typically does not require removal. If damage is noticeable
or seat is excessively worn, replace the seat before reassembly.
7.Refertowww.zurn.comtondZW205instructionsheetfor
more detailed instructions for disassembly and reassembly of
main valve.
REASSEMBLY
Prior to reassembly clean, inspect, and replace any parts as
needed.
1. Using a vise, diaphragm assembly can be held and as-
sembled in the reverse order as disassembly section.
2. Clamp valve stem hex in a vise and reassemble diaphragm
assembly. Make sure to center diaphragm on plunger before
placing diaphragm disc. Refer to ZW205 instruction sheet at
www.zurn.com or call product support 877-222-5356 for further
assistance.
3. Once diaphragm assembly is assembled, gently lower
stem into seat guide. Rotate diaphragm as needed until bolt
holes line up with body bolt holes.
4. Install spring then the cover. Tighten bolts in a cross pat-
tern. Be careful not to pinch the diaphragm when inserting and
tightening cover bolts.
5.Reattachpilotassemblyandtightenallboltsandttingas
needed. Test system per UL standard NFPA 25.
ZURN WILKINS
1747 Commerce Way, Paso Robles, CA 93446 Phone:[phone] Fax:[phone]
®
www.zurn.com
0
1
10
100
10 1001000 10000
PRESSURE DROP (PSI)
FLOW (GPM)
BODY MINIMUM FRICTION LOSS
2" Globe
2" Angle
2-1/2" Globe
2-1/2" Angle
3" Globe
3" Angle
4" Globe & Angle
6" Globe
6" Angle
8" Globe
8" Angle
10" Globe
10" Angle
Note: If the valve discharges to atmosphere regularly adequate back pressure is very important to prevent damage to
valve, throttle discharge from valve with a gate or buttery valve.

ZURN WILKINS
1747 Commerce Way, Paso Robles, CA 93446 Phone:[phone] Fax:[phone]
ISZW205FP-2-10 (REV. C 6/17)
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
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