3
Test Procedures
Double Check Valve Assemblies
Test Check Valve No.1
Step 1: Ensure shutoff #1 is open, shutoff #2 is closed.
Step 2: Connect high side hose to test cock #3, low side to
test cock #2 and open both test cock #2 and test
cock #3.
Step 3: Open valve C, then open A to bleed air from the high
side. close valve a, then open B to bleed low side.
Close valve B.
Step 4: Connect vent hose loosely to test cock#1. Open valve
A to vent air from vent hose, Tighten vent hose at test
cock #1, open test cock #1.
Step 5: Close shutoff #1. Slowly loosen hose at test cock #2
until differential gauge rises to 2psi and retighten
hose. If the differential reading does not decrease,
record check valves as “tight”.
Test Check Valve No. 2
Step 1: Move the high side hose to test cock #4, low side to
test cock #3 and open both test cock #3 and test
cock #4. Remove vent hose from test cock #1, open
shutoff #1.
Step 2: Open valve C, then open valve A to bleed air from the
high side. Close valve A, then open valve B to bleed
low side. Close valve B.
Step 3: Connect vent hose loosely to test cock #1. Open
valve A to vent air from the vent hose, Tighten vent
hose at test cock #1, open test cock #1.
Step 4: Close shutoff #1, then slowly loosen hose at test cock
#3 until differential gauge rises to 2psi and retighten
hose. If the differential reading does not decrease,
record check as tight. Remove all hoses and restore
valve to original working condition.
Note:
The assembly will fail both the first and second
check valve tests above, if shutoff #2 leaks exces-
sively. To test for a leaky #2 shutoff, use the follow-
ing procedure.
Test for Leaky No. 2 shutoff
Step 1: Connect the high side to test cock #1, low side to
test cock #4. Open test cock #1 and test cock #4.
Close shutoffs #1 and #2.
Step 2: Close valve C. Open valve A, then open valve B
1
⁄
2
turn, loosen hose at test cock #4 to remove air.
Retighten hose.
Step 3: If the differential gauge rises above 0, there is exces-
sive leakage at shutoff #2 and it must be replaced to
test the assembly.
Ball Type Test Valves
A
C
B
Needle
Valve
High Hose
(Yellow)
Low Hose
White or Red
Vent Hose
(Blue)
Test Cock
Test Cock
Test Cock
Test Cock
No. 1
No. 2
No.3
No.4
