Cashco 1000 Cryogenic - Manual (Page 10)

10 IOM-1000HP-Cryogenic
Possible Causes Remedies
A. Regulator not closing tightly. A1.
A2.
A3.
A4.
A5.
A6.
Overly compressed range spring; i.e. approaching solid height. Use
next higher range spring. Contact factory.
Inspect the seating. Clean and lap metal seat surfaces; replace if
lapping does not remedy. If composition seats are depressed, nicked
or embedded with debris, replace seat disc.
Diaphragm setting too high; check setting.
Inlet pressure too high for orifi ce size; check permissable inlet (P
1
)
pressure level for a given outlet. Change to reduced port if re-
quired.
Leakage past pressed in valve seat ring; consider integral seat.
When diaphragm sub-assembly was put into place, the rocker arm
got between the stud collar and the stud nut rather than on top of
the stud collar.
B. Downstream block. B. Check system; isolate (block) fl ow at regulator inlet, not outlet. Re-
locate regulator if necessary.
C. No pressure relief protection. C. Install safety relief valve, or rupture disc.
D. Restricted diaphragm movement. D1.
D2. Diaphragm setting too high; check and lower as required.
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.
4. Excessive pressure downstream.
Possible Causes Remedies
A. Plugged spring chamber vent. A. Clean vent opening.
B. Plugged piston or jet zone. B. Remove trim and clean.
C. Plugged drain and vent opening. C. Clear opening & purge.
5. Sluggish operation.
Possible Causes Remedies
A. Over-pressurization downstream resulting in:
1. Bent metal diaphragm(s).
2. Sprung rocker arm.
3. Range spring overstressed/fatigued. A1.
A2.
A3.
Replace diaphragms. Correct potential source of downstream over-
pressure.
Check measurements of rocker arm. Replace if necessary.
Replace range spring; consider next higher range spring.
6. Frequent resetting of setpoint.