Cashco DAP - Manual (Page 8)

IOM-DAP 8
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 regulator itself is not defective, but one or more of the accessories may be. Sometimes the pro cess may be
causing diffi culties.
The key to effi cient 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 fl uid properties) • Range of outlet pressure
• Range of fl ow rate • Range of fl uid temperature
• Range of inlet pressure • Range of ambient temperature
Pressure readings should be taken at every location that 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 an
orifi ce or needle valve in external sensing line.
C. Oversized regulator. C. Check actual fl ow conditions; resize regulator for
min i mum and maximum fl ow; 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 large piston. A. Install valve on external sensing port and bleed off
air.(Install regulator upside down to help prevent
re oc cur rence.)
3. Downstream pressure will not reach desired setting.
Possible Causes Remedies
A. Supply pressure is down (confi rm on pressure
gauge).
A. Increase supply pressure.
B. Undersized regulator. B. Check actual fl ow conditions; resize regulator for
min i mum and maximum fl ow; if necessary, replace
with larger regulator.
C. Pressure loading system pressure restricted. C1.
C2.
C3. Clean restriction or bleed orfi ces.
Clean fi lter(s).
Clean loading pressure control device.
D. Faulty loading pressure control device. D. Replace/repair loading pressure control device.