FEBCO TK-1 Backflow Preventer Test Kit - Manual (Page 3)

Test Procedure for Reduced
Pressure Assembly
A. All needle valves must be closed on test kit.
B. Open test cock No. 4 and flush test cocks Nos. 1, 2 and 3 on reduced
pressure assembly then close test cock No. 4.
C. Attach hoses as shown. Bleed air from kit, close No. 2 shutoff.
Test No. 1 - Check Valve No. 2
Purpose: To test check valve No. 2 for tightness against reverse flow.
Requirements: Valve must be tight against reverse flow under all pressure
differentials.
Step 1
Slowly open the needle valve "A" high side (red) and "C" bypass
(yellow). Keep the "B" low (blue) closed.
Step 2 Open test cock No. 4. Open test cock No. 2 and test cock No. 3
after opening test cock No. 4.
Step 3 Indicated pressure differential will decrease slightly. If pressure
differential continues to decrease (until the vent opens ) the No.
2 checkvalve is reported as "leaking".
Test No. 2 - Shutoff Valve No. 2
Purpose: To test shutoff valve No. 2 for tightness.
Step 1
After passing Test No. 1, continue to test No. 2 by closing test
cock No. 2.
Step 2 The indicated pressure differential will decrease slightly. If pres-
sure differential continues to decrease (approaching "zero") the
No. 2 shutoff valve is reported to be "leaking".
Note: A leaking No. 2 shutoff will give a false reading in tests No. 3 and 4.
Test No. 3 - To test No. 1 Check Valve
Purpose: To test check valve No. 1 for tightness.
Requirements: Valve must be tight against reverse flow under all pressure
differentials.
Step 1
Close needle valve "A" high side (red) and open test cock No. 2.
Step 2 Close test cock No. 4. Disconnect bypass hose (yellow) at test
cock No. 4.
Step 3 Open needle valve "B" low (blue) and "C" bypass (yellow), bleed-
ing to atmosphere, then closing needle valve "B" (blue) restores
the system to a normal static condition.
Step 4 Observe the pressure differential gauge. If there is a decrease in
the indicated value, the No. 1 check valve is reported as "leaking"
Test No. 4 - Pressure Differential Relief Valve
Purpose: To test operation of pressure differential relief valve.
Requirements: The pressure differential relief valve must operate to main-
tain the "zone" between the two check valves at least 2psi (14 kPa) less
than the supply pressure.
Step 1
Close needle valve "C" bypass (yellow).
Step 2 Open needle valve "A" high side (red).
Step 3 Open needle valve "B" low (blue) very slowly until the differential
gauge needle starts to drop.
Step 4 Hold the valve at this position and observe the gauge reading
at the moment the first discharge is noted from the relief valve.
Record this as the opening differential pressure of the relief
valve. Note: it is important that the differential gauge needle
drops slowly.
Step 5 Close test cocks Nos. 2 and 3. Remove hose from test cocks
Nos. 2 and 3.
Step 6 Use bypass hose (yellow) to relieve pressure from test kit by
opening needle valve "A", "B" and "C" and bleed valves "A" and
“B”.
Step 7 Remove all test equipment and open No. 2 shutoff valve of the
device.
Bleed Valve A
Bleed Valve B
High
(red)
Bypass
(yellow)
3
Low
(blue)
860 Shown