Install Instructions
Reduced Pressure Zone Assemblies must be inspected and test-
ed periodically, in accordance with local codes, to ensure proper
operation of check valves within the unit.
A differential pressure gauge is recommended for Test No. 1 rather
than a manometer for the following reasons: It utilizes minimum time
to perform the test. It eliminates the necessity of closing the inlet ball
valve which could release pipe scale and foreign matter into the
backflow preventer. Only a slight amount of water is ‘spilled’ in test.
A mercury manometer could cause a pollution hazard.
Test Set Up
Reduced Pressure Zone Assembly
Close Valves A, B and C on Test Kit.
Connect high side hose to test cock #2
Connect low side hose to test cock #3. Close shutoff #2.
Open test cocks #2 and #3.
Open vent valve C.
Open ‘high’ valve A and bleed to atmosphere until all the air is
expelled.
Close valve A. Open ‘low’ valve B and bleed to atmosphere until
all air is expelled. Close ‘low’ valve B. Close ‘vent’ valve C.
Connect vent hose to test cock #4.
Test Procedure
Reduced Pressure Zone Assembly
Field Test Equipment Required
Reduced Pressure Zone Backflow Preventer Test Kit
Test No. 1
Purpose: To test Check Valve No. 2 for tightness against reverse flow.
Requirements: Valve must be tight against reverse flow under all
pressure differentials. Slowly open the ‘high’ valve A and the
‘vent’ valve C, and keep the ‘low’ valve B closed. Open test
cock #4. Indicated pressure differential will decrease slightly. If
pressure differential continues to decrease (until the vent opens),
check valve #2 is reported as ‘leaking’.
Test No. 2
Purpose: To test shutoff #2 for tightness.
Requirements: After passing Test No. 1, continue to Test No. 2 by
closing test cock #2. The indicated pressure differential will
decrease slightly. If pressure differential continues to decrease
(approaching “zero”), shutoff #2 is reported to be “leaking”.
Test No. 3
Purpose: To test Check Valve No. 1 for tightness.
Requirements: Valve must be tight against reverse flow under all
pressure differentials. Close ‘high’ valve A and open test cock
#2. Close test cock #4. Disconnect vent hose at test cock #4.
Open valves B and C, bleeding to atmosphere. Then closing
valve B restores the system to a normal static condition. Observe
the pressure differential gauge. If there is a decrease in the indi-
cated value, Check Valve No. 1 is reported as “leaking”.
Test No. 4
Purpose: To test operation of pressure differential relief valve.
Requirements: The pressure differential relief valve must operate
to maintain the “zone” between the two check valves at least
2psi less than the supply pressure. Close ‘vent’ valve C. Open
‘high’ valve A. Open the ‘low’ valve B very slowly until the differ-
ential gauge needle starts to drop. 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 differen-
tial pressure of the relief valve.
Note: It is important that the differential gauge needle drops slowly.
Close test cocks #2 and #3. Use ‘vent’ hose to relieve pressure from
test kit by opening valves A, B and C. Remove all test equipment
and open shutoff #2.
Test Procedures
Reduced Pressure Zone Assemblies
Ball Type Test Valves
(A)
(C)
(B)
Needle
Valve
High Hose
(Yellow)
Low Hose
(White or Red)
Vent Hose
(Blue)
Test Cock
No. 1
Test Cock
No. 2
Test Cock
No. 3
Test Cock
No. 4
Auxiliary
Test Cock
Caution: To prevent freezing, hold Test Kit vertically to drain differential gauge and hoses prior to placing in case.
RP/IS-009 0829 EDP# 1911300 © 2009 Watts
USA: 815 Chestnut St., No. Andover, MA 01845-6098; www.watts.com
Canada: 5435 North Service Rd., Burlington, ONT. L7L 5H7; www.wattscanada.ca
A Watts Water Technologies Company