Vii. trouble shooting guide – Cashco PBE-H Pressure Build Economizer User Manual

Page 5

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IOM-PBE-H

5

2. Regulator can't pass suffi cient fl ow.

VII. TROUBLE SHOOTING GUIDE

1. Erratic operation; chattering.

SECTION VII

Possible Causes

Remedies

A.

Oversized regulator; inadequate rangeability. A1.

A2.
A3.

A4.
A5.

Check actual fl ow conditions, re-size regulator for minimum and maximum fl ow.
Increase fl ow rate.
Decrease regulator pressure drop; decrease inlet pressure by placing a throttling orifi ce
in inlet piping union.
Install next step higher range spring. Contact factory.
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.

Possible Causes

Remedies

A.

Regulator undersized.

A1.
A2.

Confi rm by opening bypass valve together with regulator.
Check actual fl ow conditions, re-size regulator; if regulator has inadequate capacity,
replace with larger unit.

B.

Incorrect range spring (screwing in CW of ad-
justing screw does not allow bringing pressure
level up to proper level).

B.

Replace range spring with proper higher range. Contact factory.

C.

Too much droop.

C1.
C2.

Review droop expected.
Contact factory.

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.
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-temperature conditions.
Downstream (outlet) pressure buildup occurring that overstresses diaphragms. Relo-
cate regulator or protect with safety relief valve.

4. Excessive pressure downstream.

Possible Causes

Remedies

A.

Regulator not closing tightly.

A.

Inspect the seating. Clean 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.

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, reorient regulator.

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