8
SYMPTOM
PROBLEM
SOLUTION
TROUBLESHOOTING GUIDE
Always follow existing company procedure concerning identifying equipment for inspection, and removing equipment from
service. The following is intended as a general guide in helping resolve most problems encountered in repairing clapper
check valves. If problems are not covered here please contact Weir SPM for assistance at (817) 246-2461.
1. Rapid erosion
2. Shuddering (Rapid
opening and closing)
3. Loss of pressure (Valve
does not seal or loses
fluid through discharge)
4. Valve leaks through
weephole or between
valve body and cap
5. Valve releases higher or
lower than intended relief
pressure
a) Used as continuous bypass
b) Used beyond rated capacity
a) System pressure hovering at set pressure
a) Valve not set properly
b) Damaged main seal assembly
c) Damaged discharge nozzle or wear sleeve
d) Damaged high pressure cylinder connection
e) Contaminants trapped between wear sleeve
and nozzle or main seal
a) Damaged inner or outer or both flange seals
a) Valve set incorrectly
a) Use only as an emergency unloading device
b) Install sufficient quantity of valves to meet capacity
requirements
a) Raise set pressure slightly
a) Set valve correctly.
b) Replace damaged parts
c) Replace damaged parts
d) Replace damaged parts
e) Clean affected parts
a) Replace damaged seals
a) Reset valve to desired pressure per instructions in
Section VIII
Line Set
Pressure PSI
1000
1500
2000
2500
3000
3500
4000
4500
5000
5500
6000
6500
7000
7500
8000
8500
9000
9500
10000
10500
11000
11500
12000
12500
13000
13500
14000
14500
15000
Required Nitrogen
(or gas) PSI
37
55
73
91
109
127
145
163
181
199
217
235
253
271
288
306
324
342
360
378
396
414
432
450
468
486
504
522
540
Chart. 1
The 3” Full Bore Emergency Unloading Valve
Performance Data Values in Chart 1 are for
initial set pressures.
