Model ZW105FP
Fire Protection, Pressure Relief Valve
a ZURN company
TM
SPECIFICATION SUBMITTAL SHEET
LI
STED
APPLICATION
The Fire Pump Pressure Relief Valve is a designed specifically to automatically relieve excess pressure in fire protection system. Pilot controlled, it maintains positive system
pressure at the pump discharge within very close limits as
demands change. When fire demand slows or ceases, the
Pressure Relief Valve opens, diverting entire pump output
to discharge, allowing fire pump to be stopped without
causing surging in the lines.
R
R
FM
APPROVED
SIZES
GLOBE:
ANGLE:
Threaded ends
Flanged ends
Threaded ends
Flanged ends  2" thru 3”
 2" thru 10”
 2” thru 3”
 2" thru 10”
TEMPERATURE RATING:  water 33°F to 180°F
PILOT SPRING RANGES: 20 to 200 psi (150 class standard)
100 to 300 psi (300 class)
MATERIALS
Main Valve Body
Main Valve Bonnet
Disc Guide
Seat
Disc
Diaphragm
Stem Spring
Ductile Iron ASTM A536
Ductile Iron ASTM A536
Bronze ASTM B 62
Bronze ASTM B 62
Buna-N Rubber
Nylon reinforced Buna-N
Stainless Steel
Stainless Steel
UL/ULC LISTINGS FM APPROVALS WITH RATED PRESSURES
FEATURES
 Epoxy Coated, FDA approved
 Pilot Assembly
SIZE
MAIN VALVE OPTIONS
____
Size ____ Y - 300lb. class flange (300psi max.)
____ TH - Threaded ends (400 psi max.)
____ AN - Angle body
THREADED
150 CLASS
300 CLASS
1.5
ULC-250
ULC-400
2
ULC-250
ULC-400
2.5
ULC-250
ULC-400
ULC-250,FM-250in/200out
UL-300,ULC-400,FM-400in/200out
4
ULC-250,FM-250in/200out
UL-300,ULC-400,FM-400in/200out
6
ULC-250,FM-250in/200out
UL-300,ULC-400,FM-400in/200out
8
ULC-250,FM-250in/200out
UL-175,ULC-400,FM-400in/200out
10
ULC-250
ULC-400
3
FM-400
DIMENSIONS
B
DIM
G
A
ANSI CLASS
2 1/2
3
4
6
8
Threaded
9 3/8
11
12 1/2
-
-
-
-
150 Flanged
9 3/8
11
12
15
20
25 3/8
29 3/4
10
11 5/8
13 1/4
15 5/8
21
26 3/8
31 1/8
3 5/16
4
4 9/16
5 3/4
7 7/8
10
11 13/16
300 Flanged
B
H
C
D
12 1/4
12 1/2
13
1 1/2
1 11/16
2 9/16
3 3/16
Threaded
3 3/4
5 1/2
6 1/4
-
-
-
-
150 Flanged
4 3/4
5 1/2
6
7 1/2
10
12 3/4
14 7/8
300 Flanged
5
5 7/8
6 3/8
7 7/8
10 1/2
13 1/4
15 9/16
Threaded
3 1/4
4
4 1/2
-
-
-
-
150 Flanged
3 1/4
4
4
5
6
8
8 5/8
300 Flanged
3 1/2
4 5/16
4 3/8
5 5/16
6 1/2
8 1/2
9 5/16
6
6 11/16
7 3/4
7 7/8
8 1/2
9 3/4
13 1/4
F
F
A
E
INLET
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12
D
E
CENTER TO END
G&H
14 5/16 16 5/16
10
C
C
OUTLET
OUTLET
INLET
VALVE SIZE inches
2
4 5/16
5 5/16
18
9 1/4
DOCUMENT #: REVISION:
REG-ZW105FP
1/08 WILKINS a Zurn company, 1747 Commerce Way, Paso Robles, CA 93446 Phone:805/238-7100 Fax:805/238-5766
In Canada: ZURN INDUSTRIES LIMITED, 3544 Nashua Dr., Mississauga, Ontario L4V 1L2 Phone:905/405-8272 Fax:905/405-1292
Product Support Help Line: 1-877-BACKFLOW (1-877-222-5356) • Website: http://www.zurn.com
PILOT SYSTEM
DIMENSIONS
inches
2
2 1/2 3
mm
50
65
80
X Max. (inches)
12.5 12.75 13
Y Max. (inches)
4
4.5
5
Z Max. (inches)
6.5
7
8
Valve Size
X
X
Y
Y
INLET
4
6
8
10
100
150
200
250
13.25 15.75 17.25 20.25
6
8
10.25
12
9
9.5
11.5
12.5
ANGLE
GLOBE
Z
Z
INLET
TYPICAL INSTALLATION
PILOT SYSTEM SPECIFICATIONS
Materials
Standard Pilot System Materials
Pilot Control:
Bronze ASTM B62
Trim:
Stainless Steel Type 303
Rubber:
Buna-N Synthetic Rubber
Tubbing & Fitting:
Copper and Bronze
FIRE
PUMP
CHECK VALVE
FLOW CHARACTERISTICS
Valve
Size
ZW105FP
inches
2
2 1/2
3
4
6
8
10
mm
50
65
80
100
150
200
250
208
300
500
1000 2500
5000
11000
NFPA 20 Maximum
Recommended GPM
OPERATION SEQUENCE
At pump start, the Relief Valve modulates to relieve excess pump capacity, maintaining positive system pressure at the
pump discharge.
When fire demand slows or ceases, the Model ZW105FP opens, diverting entire pump output to discharge, allowing the
fire pump to be stopped without causing surging in the lines.
(Please note that if the Model ZW105FP is to be used on a continuous duty basis to maintain fire-system pressure, suitable
back pressure must be provided on the valve to prevent cavitation damage. Consult the factory for details.)
SPECIFICATIONS
The Fire Pump Pressure Relief Back Pressure Valve shall modulate to relieve excess pressure in a fire protection system.
It shall maintain constant pressure in the system regardless of demand changes. It shall be pilot controlled and back
pressure shall not affect its set point. It shall be actuated by line pressure through a pilot control system and open fast in
order to maintain steady system pressure as system demand decreases. It shall close gradually to control surges and
shall re-seat drip-tight within 5% of its pressure setting. The main valve shall be of the hydraulically-operated, pilot-controlled, diaphragm-type, globe or angle valve. It shall have a single, removable, teflon-coated seat, a delrin-sleeved stem
guided at both ends, and a resilient disc with a rectangular cross section, being contained on 3 1/2 sides. No external
packing glands shall be permitted and the diaphragm shall not be used as a seating surface. The pilot control shall be
a direct-acting, adjustable, spring-loaded, diaphragm-type valve designed for modulating service to permit flow when
controlling pressure exceeds spring setting. This valve shall be UL Listed and Factory Mutual approved. The Pressure
Relief Back Pressure Valve shall be a WILKINS Model ZW105FP.
JOB NAME
CONTRACTOR
JOB LOCATION
ENGINEER
WILKINS a Zurn company, 1747 Commerce Way, Paso Robles, CA 93446 Phone:805/238-7100 Fax:805/238-5766
IN CANADA: ZURN INDUSTRIES LIMITED, 3544 Nashua Dr., Mississauga, Ontario L4V 1L2 Phone:905/405-8272 Fax:905/405-1292
Product Support Help Line: 1-877-BACKFLOW (1-877-222-5356) • Website: http://www.zurn.com
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