Cashco 6987 User Manual
Page 5
IOM-6987
5
SECTION VII
VII. TROUBLE SHOOTING GUIDE
Possible Causes
Remedies
A.
Oversized regulator.
A1.
A2.
A3.
A4.
A5.
Check actual fl ow conditions, resize regulator for minimum and maxi-
mum fl ow.
Increase fl ow rate.
Decrease regulator pressure drop; decrease inlet pressure by placing
throttling orifi ce in inlet piping union.
Install next step higher range spring. Contact factory
Before replacing regulator, contact factory.
B.
Inadequate rangeability.
B1.
B2.
B3.
Increase fl ow rate.
Decrease regulator pressure drop.
Install next step higher range spring. Contact factory
C.
Worn piston/cylinder; inadequate guiding.
C.
Replace renewal unit.
1. Erratic Operation; chattering.
Possible Causes
Remedies
A.
Regulator undersized.
A1.
A2.
Confi rm by opening bypass valve together with regulator.
Check actual fl ow conditions, resize regulator; if regulator has in ad e-
quate capacity, replace with larger unit.
B.
Plugged renewal unit.
B.
Remove renewal unit and check for plugged holes in cylinder.
C.
Incorrect range spring (screwing out CCW of adjust-
ing screw does not allow bringing pressure level to a
stable and proper level).
C.
Replace range spring with proper lower range. Contact factory.
D.
Too much proportional band (rise).
D1.
D2.
Review P.B. (rise) expected.
Contact factory.
E.
Restricted diaphragm movement.
E.
Ensure no moisture in spring chamber at temperatures below freezing.
Ensure no dust or debris entering vent opening. If rainwater or debris
can enter, re-orient spring chamber.
2. Regulator inlet (upstream) pressure too high.
Possible Causes
Remedies
A.
Normal-life diaphragm failure.
A.
Replace diaphragms.
B.
Abnormal short-life diaphragm failure.
B1.
B2.
B3.
B4.
Can be caused by excessive chattering. See No. 1 to remedy chatter.
Can be caused by corrosive action. Consider alternate diaphragm
material.
For composition diaphragms, ensure not subjecting to over-tem pera ture
conditions.
Upstream (inlet) pressure buildup occuring that overstresses di a -
phragms.
3. Leakage through the spring chamber vent hole.
Possible Causes
Remedies
A.
Plugged spring chamber vent.
A.
Clean vent opening.
B.
Plugged piston guides.
B.
Re move renewal unit and clean.
C.
Fluid too viscous
C.
Heat fl uid. Contact factory.
4. Sluggish
Operation.