Cashco 5381 - Manual (Page 5)

IOM-5381 5
A. Regulator not closing tightly. A. 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 trim.
B. Downstream block. B. Check system; isolate (block) fl ow at regulator inlet - not outlet. Relocate
regulator if necessary.
C. No pressure relief protection. C. Install safety relief valve, or rupture disc.
D. Restricted diaphragm movement. D. Assure no moisture in spring chamber at temperatures below freeze point.
Assure no dust or debris entering vent opening. If rainwater or debris can
enter, re-orient regulator.
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, assure not subjecting to over-temperature
conditions.
B4. Downstream (outlet) pressure buildup occurring that overstresses
diaphragms. Relocate regulator or protect with safety relief valve.
C. O-ring failure. C. Replace O-ring (15), apply appropriate torque.
A. Oversized regulator; inadequate rangeability. A1. Check actual fl ow conditions, re-size regulator for minimum and maximum
fl ow.
A2. Increase fl ow rate.
A3. Decrease regulator pressure drop; decrease inlet pressure by placing a
throttling orifi ce in inlet piping union.
A4. Install next step higher range spring. Contact factory.
A5. Before replacing regulator, contact factory.
B. Worn piston; inadequate guiding. B. Replace trim ( possible body replacement).
C. Weakened/broken piston spring. C. Replace piston spring. De ter mine if corrosion is causing the failure.
SECTION VII
Possible Causes Remedies
Remedies Possible Causes
2. Regulator can't pass suffi cient fl ow.
A. Regulator undersized. A1. Confi rm by opening bypass valve together with regulator.
A2. Check actual fl ow conditions, re-size regulator; if regulator has inadequate
capacity, consult factory.
B. Incorrect range spring (screwing in CW of adjust- B. Replace range spring with proper higher range. Contact factory.
ing screw does not allow bringing pressure level
up to proper level).
C. Too much droop. C1. Review droop expected.
C2. Contact factory.
Remedies Possible Causes
3. Leakage through the spring chamber vent hole.
1. Erratic operation; chattering.
VII. TROUBLE SHOOTING GUIDE
4. Sluggish operation.
Remedies Possible Causes
A. Fluid too viscous. A. Heat fl uid. Contact factory.
Possible Causes Remedies
5. Excessive pressure downstream.