Watts AMES 4000SS Series, Installation And Repair Manual, Page: 7 / 8

7
Problem Identification Procedures
When using differential pressure gauge
Check differential across No. 1 check valve
READING
PROBLEM
2 to 3 psid Leak in No. 1 or No. 2 check valve
4 to 7 psid and steady Malfunctioning pressure relief valve
2 to 7 psid Inlet pressure fluctuation
Without using differential pressure gauge
A. Close gate valve No. 2
RESULT
PROBLEM
If discharge stops Leak in No. 2 check valve
If discharge does not stop Go to B
B. Open No. 4 test cock to produce a flow greater than
differential relief valve discharge
RESULT PROBLEM
If discharge stops Leak in No. 1 check valve
If discharge does not stop Malfunctioning pressure relief valve
PROBLEM CAUSE SOLUTION
Assembly discharges from differential relief valve during
no flow condition Fouled first check Disassemble and clean check valve #1
Fluctuating inlet pressure Control supply line water pressure
Install a soft-seated, spring-loaded check valve upstream
of the assembly
Outlet pressure higher than inlet pressure and leak in
check valve #2 Disassemble and clean check valve #2 and identify cause
of backpressure
Leak through diaphragm or around flange bolt holes of
relief valve Service relief valve
Pressure relief valve does not close See problem 'Pressure relief valve does not close'
Assembly discharges from differential relief valve during
a flow condition Check valve #1 wedged open Disassemble and clean check valve #1
O-ring displaced from groove in check #1 Disassemble and replace
Pressure relief valve does not close See problem 'Pressure relief valve does not close'
Fluctuating line pressure Install pressure sustaining check upstream of backflow
Differential pressure relief valve does not open during test Differential pressure across check valve #1 stays above
2.0 psi due to leaking outlet gate valve Repair shutoff valves
Weak or broken relief valve spring Disassemble and replace relief valve spring
Shutoff seat tube bound in body Disassemble and repair
Plugged hydraulic hose Disassemble and repair
Pressure relief valve does not close Debris on sealing surface Remove relief valve and clean
Plugged hydraulic hose Disassemble and clean
Damaged seat or rubber shutoff disc Remove relief valve assembly and replace
Ruptured diaphragm Disassemble and replace diaphragm
Wrinkled or improperly installed diaphragm Disassemble and properly position diaphragm
Troubleshooting