WILKINS 450, 450DA Instructions Manual

Model 450 & 450DA

a company

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PROTECTIVE
ENCLOSURE

6" MIN.

WILKINS VALVE
SETTER MJFS

DIRECTION OF FLOW

Double Check Valve Assembly (4” & 6”)
Double Check Detector Assembly (4” & 6”)

 Installation  Testing  Maintenance Instructions

(Patent No. 5,913,331)

INSTALLATION INSTRUCTIONS

CAUTION: Installation of Backow Preventers must be performed by qualied, licensed
personnel. The installer should be sure the proper device has been selected for the particular
installation. Faulty installation could result in an improperly functioning device.

WILKINS Model 450 Double Check Valve assemblies are for use on potable water lines
where a health hazard does not exist in the event of a backow situation.

Damage to the device could result wherever water hammer and/or water thermal expan­sion could create excessive line pressure. Where this could occur, shock arrestors, check
valves and/or pressure relief valves should be installed downstream of the device.

If installation is in a pit or vault, the Backow Preventer must never be submerged in
water because this could cause a cross-connection. Make sure that the pit or vault always
remains dry by providing ample drainage.

1. Before installing a Model 450 Backow Preventer, ush the line thoroughly to
remove all debris, chips and other foreign matter. If required, a strainer should be
placed upstream of the Backow Preventer. CAUTION: Do not use a strainer in
seldom used emergency waterlines such as re lines.

2. Provide adequate space around the installed unit so that the test cocks will be
accessible for testing and servicing.

3. Install valve at least 6 inches above surrounding ood level.

PLACING THE DEVICE IN SERVICE

1. Start with both shut-off valves closed.
Slowly open the inlet shut-off valve until the
backow preventer is completely pressur­ized.

2. When the unit has been pressurized,
vent any trapped air by slightly opening
each of the four test cocks.

3. Slowly open the downstream shut-off
valve. The Model 450 Double Check Valve
assembly is now in service.

4. After the Model 450 has been prop­erly installed, test the device (see “TEST
PROCEDURES”). If the device fails the
test, remove the rst and second check
valves and thoroughly ush the device.
Clean rubber and seats of all debris and
place unit back in service.

4. Always consult local codes for installation methods, approvals and guidance.

TYPICAL HORIZONTAL ORIENTATION

OUTDOOR INSTALLATION

The Model 450 Backow Preventer may be installed outdoors only if the device is
protected against freezing conditions. Exposure to freezing conditions will result in
improper function or damage to the device. The installation location must be kept above
32°F. All the basic installation instructions apply.

INDOOR INSTALLATION

Indoor installation is preferred in areas
that are subject to freezing conditions. All
the basic installation instructions apply to
such installations.

Proposition 65 Warning This product contains chemicals known to the State of California to cause cancer or birth defects
or other reproductive harm.

WILKINS, a ZURN company

1747 Commerce Way, Paso Robles, CA 93446 Phone:[phone] Fax:[phone]

Testing Procedures

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HIGH SIDE HOSE

LOW SIDE HOSE

BY PASS HOSE

LOW SIDE BLEED
NEEDLE VALVE
(behind body)

HIGH SIDE BLEED

NEEDLE VALVE

(behind body)

BLEED TUBE

FILTERS

#1 TEST COCK

#2 TEST COCK

#2 SHUT-OFF

VALVE

#1 SHUT-OFF

VALVE

#4 TEST COCK

#3 TEST COCK

MODEL 450 DOUBLE CHECK VALVE ASSEMBLY

Equipment Required: Differential pressure gauge test kit.

TEST NO. 1 - TIGHTNESS OF #1 CHECK VALVE

REQUIREMENT:

The static pressure drop across check valve #1 shall be at least

1.0 psid. If test cock #3 is not at the highest point of the check
valve body, then a vertical tube must be installed on test cock #3
so that it rises to the top of the check valve body.

PROCEDURE:

1. Slowly open all 4 test cocks to remove any foreign material
and attach ttings.

2. Attach hose from the high side of the test kit to the #2 test
cock.

3. Open test cock #2 and bleed all air from the hose and gauge
by opening the high side bleed needle valve. Close high side
bleed needle valve. If a tube is attached to test cock #3,
open test cock #3 to ll the tube. Close test cock #3.
Close #2 shut-off valve then close the #1 shut-off valve.

4. Hold gauge at same level as test cock #3 or water level in
tube. Slowly open test cock #3. Record the static pressure

drop across check valve #1 after gauge reading stabilizes
and water stops running out of test cock #3.

5. Close all test cocks, open shut-off valve #1 and remove test
equipment.

TEST NO. 2 - TIGHTNESS OF #2 CHECK VALVE

REQUIREMENT:

The static pressure drop across check valve #2 shall be at least

1.0 psid. If test cock #4 is not at the highest point of the check
valve body, then a vertical tube must be installed on test cock #4
so that it rises to the top of the check valve body.

PROCEDURE:

1. Attach hose from the high side of the test kit to the #3 test cock.

2. Open test cock #3 and bleed all air from the hose and gauge
by opening the high side bleed needle valve. Close high
side bleed needle valve. If a tube is attached to test cock
#4, open test cock #4 to ll the tube. Close test cock #4.
Close #1 shut-off valve.

3. Hold gauge at same level as test cock #4 or water level in
tube. Slowly open test cock #4. Record the static pressure
drop across check valve #2 after gauge reading stabilizes
and water stops running out of test cock #4.

4. Close all test cocks, slowly open shut-off valve #1 & #2 and
remove test equipment.

2

WILKINS, a ZURN company

1747 Commerce Way, Paso Robles, CA 93446 Phone:[phone] Fax:[phone]