Cashco DA5 User Manual
Page 10
IOM-DA5
10
of range spring is less than 55 psig, use
test pressure of 5 psig less than upper
value of range spring. If upper value of
range spring is greater than 55 psig, use
test pressure of 50 psig.
b. While applying GN
2
or air pres sur iza tion
fl uid, turn adjusting screw CCW until valve
appears to be closed. Add one additional
revolution CCW to adjusting screw.
c. Tube outlet to a beaker of water to ob serve
number of escaping gas bubbles.
3. Pressure Containment Test.
a. Pressurize inlet and outlet to 1.0 x Upper
Value of Range Spring or 30 psig with air
VIII. 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 in for ma tion 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 ap pli ca tion and op er at ing
con di tions.
It is imperative the following information be provided by the customer:
• Fluid (with fl uid properties)
• Range of fl ow rate
• Range of inlet pressure
• Range of outlet pressure
• Range of fl uid temperature
• 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 com plaints along with possible causes and remedies.
SECTION VIII
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
a 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.
1. Erratic regulation, instability or hunting.
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
re oc cur rence.)
or GN
2
, whichever is higher.
b. Soap solution test all external leak points;
plugged connections, diaphragm fl ange,
di a phragm bolting and spring chamber
vent open ing.
4. Excessive leakage will require disassembly,
examination of sealing elements, correction
of problem, reassembly and retesting. NOTE:
This valve is NOT a bubble-tight shutoff de-
vice. See DAG-TB, Table DAG-10 for leak age
classes.