Ames Fire & Waterworks 5000RPDA Reduced Pressure Detector Assemblies - Manual (Page 7)

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PROBLEM CAUSE SOLUTION
C. Differential pressure relief Differential pressure across Repair shutoff valves
valve does not open No. 1 check valve stays
during test above 2psi due to
leaking outlet gate valve
Weak or broken relief Disassemble and replace
valve spring relief valve spring
Seat tube bound in Disassemble and repair
body O-ring
Plugged hydraulic hose Disassemble and clean
D. Pressure relief valve - Debris on sealing Remove relief valve and
does not close surface clean
Plugged hydraulic Disassemble and clean
hose
Damaged mounting seat gasket Remove relief valve assembly
or seat tube and replace
Ruptured diaphragm Disassemble and replace
diaphragm
Damaged O-ring Disassemble and replace
PROBLEM IDENTIFICATION PROCEDURES -
FOR RPZ ASSEMBLIES
SERIES 4000RP AND 5000RPDA
PROBLEM: Continuous or intermittent discharge from relief valve.
1. When using differential pressure gauge 2. Without using differential pressure gauge.
A. Check differential across No. 1 check valve A. Close gate valve No. 2
Reading Problem Result Problem
2 to 3 PSID Leak in No. 1 or No. 2 check valve If discharge stops Leak in No. 2 check valve
4 to 7 PSID and steady Malfunctioning pressure relief valve If discharge does Go to B
not stop
2 to 7 PSID fl uctuating Inlet pressure fl uctuating
B. Open No. 4 test cock to product a fl ow greater
than differential relief valve discharge
Result Problem
If discharge stops Leak in No. 1 check valve
If discharge does Malfunctioning pressure
not stop relief valve