IOM-SLR-2
13
SECTION IX
IX. TROUBLE SHOOTING GUIDE
When trouble shooting this regulator there are many possibilities as to what may be causing problems. Many times, the regu-
lator itself is not defective, but one or more of the accessories may be. Sometimes the pro cess may be causing difficulties.
The key to efficient trouble shooting is information and communication. The customer should try to be as precise as possible
in their explanation of the problem, as well as their understanding of the application and operating con di tions.
It is imperative the following information be provided by the customer:
• Fluid (with fluid properties)
• Range of outlet pressure
• Range of flow rate
• Range of fluid temperature
• Range of inlet pressure
• Range of ambient temperature
Pressure readings should be taken at every location where pressure plays a role - i.e., regulator inlet (as close as possible to
inlet port), regulator outlet (as close as possible to outlet port), etc.
Following are some of the more common complaints along with possible causes and remedies.
1. Erratic regulation, instability or hunting.
Possible Causes
Remedies
A.
Sticking of internal parts.
A.
Remove internals, clean, and if necessary, replace.
B.
Load changes are too quick for system.
B.
Convert to external sensing (if necessary) and install an orifice or
needle valve in external sensing line.
C. Oversized
regulator.
C.
Check actual flow conditions; resize regulator for min i mum and maxi-
mum flow; if necessary, replace with smaller regulator.
D.
Too much variation in Inlet Pressure - P1.
D.
Consider use of a pilot for closer Outlet Pressure – P2
2. Erratic regulation, instability or hunting (liquid service).
Possible Causes
Remedies
A.
Air trapped under diaphragm.
A.
Install valve on external sensing port and bleed off air. (Install
regulator upside down to help prevent reoccurrence.
3. Downstream pressure will not reach desired setting.
Possible Causes
Remedies
A.
Supply pressure is down (confirm on pressure
gauge.
A.
Increase supply pressure.
B.
Undersized regulator.
B.
Check actual flow conditions; resize regulator for min i mum and maxi-
mum flow; if necessary, replace with larger regulator.
C.
Pressure loading system pressure restricted.
C1. Clean restriction or bleed orifices.
C2. Clean
filter(s).
C3. Clean loading pressure control device.
D.
Faulty loading pressure control device.
D.
Replace/repair loading pressure control device.
4. Diaphragm continually breaks (all regulators).
Possible Causes
Remedies
A.
Differential pressure across diaphragm may
have exceeded limits. (See Table 6 in SLR-2-
TB)
A1. Be aware of limits as well as where the various pressures are acting.
Install pressure safety equipment as necessary.
5. Leakage at diaphragm flange.
Possible Causes
Remedies
A.
Body bolts not torqued properly.
A.
Torque to proper value (see Section VII, F-10).
B.
Pressures at diaphragm may be too high.
B.
Consult factory.
