Instructions / Assembly

1
NOTE: Flushing of all pipe lines is to be performed to remove
all debris prior to installing valve.
NOTE: When installing a valve, make sure there is adequate
space around the valve for adjustments and servicing.
1. When installing a ZW205, gate valves are recommended on
both the inlet and outlet of the valve for maintenance, allowing for
isolation of valve.
2. Position the ZW205 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 in-line, double check all fasteners/
bolts in the pilot system and on the main valve are tight and there
is no damage prior to pressurizing the system.
NOTE: Pressure in some applications can be very high so be
thorough in checking and inspecting for proper installation
and makeup.
3. Zurn Wilkins valves are designed to operate in both the vertical
and horizontal positions. However, it is recommended that ZW205
6” and larger, be installation in the horizontal position. The hori-
zontal positioning of the larger valves avoids premature wear due
to the mass of the plunger assembly as well as allows for greater
accessibility during annual inspections, and maintenance.
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.
1. Open the pilot ball valves (2) in the pilot system (see ZW205
schematic).
2. Loosen the pilot adjusting screw jam nut and turn the pilot
adjustment screw clockwise until the spring is completely com-
pressed. Due not over tighten to prevent damage to the valve.
3. Then slowly open the upstream shutoff valve only enough
to slowly ll the 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.
4. 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.
5. Before setting pilot valve, if valve is equipped with SC1 speed
controls (O or L on ZW205 schematic) it is necessary to back out
the adjusting screw a minimum of 3 turns from closed position.
6. Fully open the outlet gate valve if one is installed.
7. At this point, with the upstream shut-off valve partially open,
it is advisable to ow water through the valve to ensure all air
has escaped from the system. Slowly turn the pilot adjustment
screw counterclockwise until ow starts to occur. Flow will begin
to occur when the pressure set-point of the pilot decreases
below the inlet pressure.
8. Allow a sufcient amount of water to ow, then turn the ad-
justment screw clockwise until ow stops. Fully open the up
 Installation  Troubleshooting  Maintenance Instructions
Model ZW205 LEAD-FREE*
Pressure Relief / 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
ZURN WILKINS
1747 Commerce Way, Paso Robles, CA 93446 Phone:[phone] Fax:[phone]
Installation / Start-up
stream shut-off valve.
10. Once the system has been thoroughly bled of air, set the relief
pressure by slowly turning the adjustment screw counterclockwise
until water starts to ow through the ACV. Now the relief valve is
set to the current inlet pressure. Use the table below to set the
relief pressure if desired set point is different 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 pres-
sure based on the adjustment table.
Note: The relief valve is designed for quick closing speeds.
A small amount of water will dribble from the valve when
the inlet pressure is as low as 80% of the set pressure dur-
ing normal operation.
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
*Note: Pressure change per turn is approximate. Use a
gauge at the inlet of ACV to set /check relief pressure.
11. To verify proper operation of the ZW205, view the valve
during normal operation and check the valve for relief settings.
Adjustments can be made at anytime.
12. After the pilot system has been adjusted and the valve is
properly operating the main valve opening and closing speed
controls (O or L) can be adjusted as needed.
13. When setting speed controls, turning the adjustment screw
into the speed control will restrict the amount of ow through the
the needle valve. Depending on whether the control is for opening
or closing (refer to ZW205 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 an opening speed control on a ZW205
should be at least 3 turns in from the furthest closed position to
prevent high pressure surges upstream.
ZW205 SCHEMATIC
STANDARD COMPONENTS
Item
1 Main Valve
2 850XL Isolation Valve
3 SXL "Wye" Type Strainer
4 Pressure Gauge
5 Restriction Fitting
6 Closing Speed Control
7 PV-RLF Pressure Relief Valve
OPTIONAL FEATURES
C 40XL Hydraulic Check w/
Isolation Valve
L SC1 Closing Speed Control
(Standard 1 1/4" - 4")
O SC1 Opening Speed Control
L
6
1
1 1/4"- 4"
6"- 8"
OPTIONAL
W
3
5
7
F
FLOW
Z
O
2
2
2
2
C
4
®
®
www.zurn.com