#3 TEST COCK
#4 TEST COCK
#2 SHUT-OFF
VALVE
LOW SIDE BLEED
NEEDLE VALVE
LOW SIDE HOSE
NOTE: BY-PASS OMITTED FOR CLARITY
(FOR BY-PASS TESTING REFER TO MAINTENANCE
INSTRUCTIONS FOR MODEL 350D)
#2 TEST COCK
#1 TEST COCK
(ON OPPOSITE
SIDE OF VALVE)
#1 SHUT-OFF
VALVE
HIGH SIDE BLEED
NEEDLE VALVE
HIGH SIDE HOSE
VENT HOSE
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 fill 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
MODEL 950XLTDABF Double Check Detector Assembly
Testing Procedures
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 fittings.
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 fill 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 re-
move test equipment.
ZURN WILKINS
1747 Commerce Way, Paso Robles, CA 93446 Phone:
855-663-9876
Fax:805-238-5766
®
www.zurn.com
