Cashco DL User Manual
Page 5
IOM-D/DL
5
VII. TROUBLE SHOOTING GUIDE
SECTION VII
1. Erratic operation; chattering.
Possible Causes
Remedies
A.
Oversized regulator.
A1.
Check actual fl ow conditions, resize regulator for minimum and maximum fl ow.
A2.
Decrease regulator pressure drop; decrease inlet pressure by placing a throttling orifi ce
in inlet piping union; 2-stage pressure drop by using with another regulator in series.
A3.
Install next step higher range spring. Contact factory.
A4.
Before replacing regulator, contact factory.
B.
Inadequate rangeability (regulator full capacity
approximately 50% utilized).
B1.
Decrease regulator pressure drop; decrease inlet pressure by placing a throttling orifi ce
in inlet piping union; 2-stage pressure drop by using with another regulator in series.
B2.
Install next step higher range spring. Contact factory.
C. Worn piston/cylinder; inadequate guiding.
C.
Replace trim.
D. Weakened/broken piston spring.
D.
Replace piston spring. Determine if corrosion is causing the failure; if so, then consider
alternate trims.
E.
Flow induced instability.
E.
Replace piston with piston that includes Opt-4 Stabilizer seal.
2. Downstream pressure will not reach desired setting.
Possible Causes
Remedies
A. Regulator
undersized.
A1.
Confi rm by opening bypass valve together with regulator.
A2.
Check actual fl ow conditions, resize regulator; if regulator has inadequate capacity,
replace with larger unit.
B.
Plugged trim.
B.
Remove trim and check for plugged holes in cylinder.
C. Incorrect range spring (screwing in CW of ad-
justing screw does not allow bringing pressure
level up to proper level).
C.
Replace range spring with proper higher range. Contact factory.
D. Too much proportional band (droop).
D1.
Review P.B. (droop) expected.
D2.
Contact factory.
E.
Restricted diaphragm movement.
E.
Ensure no moisture in spring chamber at temperatures below freeze point. Ensure no
dust or debris entering vent opening. If rainwater or debris can enter, re-orient spring
chamber.
3. Leakage through the spring chamber vent hole.
Possible Causes
Remedies
A.
Normal-life diaphragm failure.
A.
Replace diaphragm.
B.
Abnormal short-life diaphragm failure.
B1.
Can be caused by excessive chattering. See No. 1. to remedy chatter.
B2.
Can be caused by corrosive action. Consider alternate diaphragm material.
B3.
For composition diaphragms, ensure not subjecting to over-temperature conditions.
B4.
Downstream (outlet) pressure buildup occuring that overstresses diaphragms. Relocate
regulator or protect with safety relief valve.
15. Spray liquid leak detector around body cap (5)
and body (1) for test for leakage. Test pres sure
should be a min i mum of 100 psig (6.9 Barg) at
the inlet. Outlet should be tested to upper value
of range spring (14) with a 100 psig (6.9 Barg)
minimum.
NOTE: When piston (15) assemblies are used
with comp seats, Cashco, Inc. does not rec om-
mend attempting to remove the comp seat. If
composition seat is dam aged, re place entire
pis ton assembly.