Zurn Wilkins P4000AHR Installation manual

1
INSTALLATION
NOTE: Prior to installation of the P4000A, ensure all debris is ushed
out the piping system.
1. During the installation of a P4000A in a sprinkler system, Underwriter
Laboratories (UL) requires NFPA 13 “Standard for Installation of
Sprinkler Systems” be followed.
2. Upon installation UL also requires that the P4000A be tested in
accordance with NFPA 13. Thereafter the valve shall be inspected,
tested, and maintained in accordance to NFPA 25 “Standard for the
Inspection, Testing, and Maintenance of Water-Based Fire Protec-
tion Systems”.
3. For making adjustments and servicing allow for adequate space
around the valve.
4. Position the P4000A 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 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.
WARNING: Supply adequate drainage on the discharge of the P4000A.
To avoid water damage, valve must be plumbed to a safe drain.
5. Zurn Wilkins valves are designed to operate in both the vertical and
horizontal positions.
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.
Installation  Start-up  Maintenance Instructions
ZURN WILKINS
1747 Commerce Way, Paso Robles, CA 93446 Phone:[phone] Fax:[phone]
®
1. Turn the adjustment screw clockwise until the valve spring is com-
pressed fully.
Caution: Do not over tighten the adjustment screw to prevent
damaging the valve.
2. With the inlet of the P4000A pressurized slowly turn the adjustment
screw counterclockwise until the rst sign of water ow. Either listen
carefully to the valve for water ow or look through a downstream
sight glass.
3. The valve is set to relieve pressure at the current inlet pressure at
the rst sign of water ow through the relief valve. If the desired set
pressure is different than current inlet pressure use the table below.
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.
NOTE: The valve must be set 10 psi greater than the maximum
anticipated system pressure.
Installation / Start-up
DESCRIPTION
The Zurn Wilkins P4000A Thermal Expansion Relief Valve is a direct
acting relief valve. The P4000A uses a spring to force the plunger down
upon a seat causing the valve to be normally closed. The P4000A can
be set to relieve pressures from 50 to 200 psi and the P4000AHR from
150 to 300 psi. When the inlet pressure reaches the set pressure point
it pushes up on the diaphragm which pulls the plunger off the seat. The
valve opens to relieve pressure at the inlet and allows water to ow
downstream. The P4000A opens and closes within a close pressure
range of the set pressure. All the instructions and references apply to
both models, P4000A & P4000AHR.
P4000A
®
Model P4000A & P4000AHR
Thermal Expansion Relief Valve
1/2" & 3/4"
www.zurn.com
Relief Pilot
Adjustment Range
Pressure Change per
Turn (PSI)*
50 - 200 23
150 - 300 28.5
*Note: Pressure change per turn is approximate. Use a gauge at
the inlet of P4000A to set /check relief pressure.
4. To verify proper operation of the P4000A, view the valve during
normal operation and check the valve for relief setting. Adjustments
can be made at anytime.
NOTICE: Annual inspection and maintenance is required of all plumbing system components. To ensure proper performance and
maximum life, this product must be subject to regular inspection, testing and cleaning.
P4000AHR
FM
APPROVED
WARRANTY: ZURN WILKINS Valves are guaranteed against defects of material or workmanship when used for the services recommended. If
in any recommended service, a defect develops due to material or workmanship, and the device is returned, freight prepaid, to ZURN WILKINS
within 12 months from date of purchase, it will be repaired or replaced free of charge. ZURN WILKINS’ liability shall be limited to our agreement
to repair or replace the valve only.
!WARNING: Cancer and Reproductive Harm - www.P65Warnings.ca.gov
!ADVERTENCIA: Cáncer y daño reproductivo - www.P65Warnings.ca.gov
!AVERTISSEMENT: Cancer et néfastes sur la reproduction - www.P65Warnings.ca.gov

2ZURN WILKINS
1747 Commerce Way, Paso Robles, CA 93446 Phone:[phone] Fax:[phone]
Open Regulating Operation
The Inlet pressure pushes upward on the diaphragm via the internal
sensing port. Once the upward force on the diaphragm is greater than
the compression force of the spring the plunger will move up off the
seat allowing water ow.
Drip Tight Closing Operation
The compressed spring forces the plunger on
the seat creating a drip tight seal.
Operation
®
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Operation
The Zurn Wilkins P4000A is a direct acting, spring controlled, pressure relief valve which opens from the force of upstream pres-
sure pushing up on the internal diaphragm. The relief set pressure can be easily adjusted by altering the compression force on the
spring in the bell. Once upstream pressure rises above the set pressure the diaphragm will further compress the spring on top of
the diaphragm allowing the plunger to rise off the seat and water to ow. When the upstream pressure drops back down below the
set pressure the compressed spring will force the plunger back on the valve seat sealing the valve drip tight. The valve will open
and close drip tight near the relief set pressure.
Maintenance Instructions
The P4000A 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 the system and then
remove the P4000A.
1. Secure valve body and turn the adjustment screw all the
way out.
2. Next remove 8 socket head screws around the bell using a
5/32” hex key. Note location of tag/inlet. Remove the bell, the
spring, and 2 spring discs.
3. Remove the spacer, but take care not to lose the small o-ring
between spacer and body. 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 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
DIRECTION
OF
FLOW
INLET OUTLET
surface. Use an adjustable wrench on the opposite nut to re-
move 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.
P4000A Valve
Reassembly
Reassembly of the P4000A 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 dia-
phragm, large washer (with the inner step against the dia-
phragm), lock washer, and 5/16” nut (chamfered side away
from diaphragm) 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.

3
ZURN WILKINS
1747 Commerce Way, Paso Robles, CA 93446 Phone:[phone] Fax:[phone]
®
www.zurn.com
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.
6. Use adjustable wrenches to tighten the plunger and
diaphragm nuts.
7. Place new sensing hole o-ring in small hole on the
spacer.
8. Install the spacer assembly on to the body with the plunger
sitting on the valve seat.
ITEM DESCRIPTION
13x8-16 Jam Hex Nut SS
2 Adjustment Cover
33/8-16 Adjustment Bolt
4 Spring Bell
5 Spring
6Spring Disc
75/16" Internal Tooth Lock Washer, SS
8 Diaphragm
9 O-ring
10 Relief Valve Stem
11 5/16" Flat Washer, SS
12 O-ring
13 Relief Plunger Assy.
14 O-ring
15 1/2" Relief Valve Body
16 5/16-18 Diaphragm Nut, SS
17 Relief Valve Seat
18 O-ring
19 O-ring
20 1/8" NPT Plug
21 Relief Valve Spacer
22 Relief Lower Diaphragm Washer
23 Tag
24 10-32 X 1-1/2" Screw
25 Relief Upper Diaphragm Disc,SS
Maintenance Instructions
23
14
24
6
25
8
22 9
10
17
14
16
15
11
12
23
7
19
6
5
18
20
13
21
9. Place a spring disk on the stem, then the spring, another
spring disk and bell.
10. Insert socket head cap screws into 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 system. For further assistance or
ordering replacement parts go to www.zurn.com or call
product support 877-222-5356.
Table 1

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ISP4000A (REV. C 6/17) www.zurn.com
Troubleshooting
Problem Possible Causes Corrective Action
1. Valve not opening 1. The spring is over compressed 1. Loosen the adjusting screw
(Valve not relieving pressure)
2. Foreign matter obstruction 2. Disassemble and remove obstruction, replace parts as
necessary
3. Damaged diaphragm or stem o-rings 3. Disassemble and replace diaphragm or o-rings
4. Stem dragging on spacer 4. Disassemble valve, and check for scale or damage on stem
and spacer o-ring
5. Plugged sensing Port/sensing line 5. Check sensing line and/or port and remove obstruction
6. Valve installed backward 6. Compare valve body with diagram on page 2 for correct
orientation
2. Valve not closing 1. Weak or no spring compression 1. Turn adjusting screw in to increase relief pressure
(Valve dripping or relieving pressure
below set pressure)
2. Spring damaged 2. Disassemble and replace spring as needed
3. Spring discs out of place 3. Disassemble and replace or adjust spring disc as
needed
4. Stem dragging on spacer 4. Disassemble valve, and check for scale or damage on stem
and spacer o-ring
5. Cut, worn or chipped plunger seal,
seat or plunger o-ring
5. Check plunger surface, seat and o-ring. Clean/replace as
needed
3. Leakage from valve 1. Damaged diaphragm, stem or spacer
o-ring
1. Disassemble and replace damaged part as needed
2. Ports not sealed 2. Remove and reinstall port ttings, use Teon tape or pipe
sealant to ensure good seal
3. Loose diaphragm nut / bell screws 3. Disassemble and re-tighten the diaphragm nut or bell screws
ZURN WILKINS
1747 Commerce Way, Paso Robles, CA 93446 Phone:[phone] Fax:[phone]
®