Manual

IOM-DA0

SECTION IX

IX. TROUBLE SHOOTING GUIDE

When trouble shooting this regulator there are many possibilities as to what may be causing problems. Many times, the regu-

lator itself is not defective, but one or more of the accessories may be. Sometimes the pro cess may be causing difﬁ culties.

The key to efﬁ cient trouble shooting is information and communication. The customer should try to be as precise as possible

in their explanation of the problem, as well as their understanding of the application and operating con di tions.

It is imperative the following information be provided by the customer:

• Fluid (with ﬂ uid properties) • Range of outlet pressure

• Range of ﬂ ow rate • Range of ﬂ uid temperature

• Range of inlet pressure • Range of ambient temperature

Pressure readings should be taken at every location where pressure plays a role - i.e., regulator inlet (as close as possible to

inlet port), regulator outlet (as close as possible to outlet port), etc.

Following are some of the more common complaints along with possible causes and remedies.

1. Erratic regulation, instability or hunting.

Possible Causes Remedies

A. Sticking of internal parts. A. Remove internals, clean, and if necessary, replace.

B. Oversized regulator.

B. Check actual ﬂ ow conditions; resize regulator for min i mum and maxi-

mum ﬂ ow; if necessary, replace with smaller size regulator.

2. Downstream pressure will not reach desired setting.

Possible Causes Remedies

A. Supply pressure is down (conﬁ rm on pressure

gauge.

A. Increase supply pressure.

B. Undersized regulator. B. Check actual ﬂ ow conditions; resize regulator for min i mum and maxi-

mum ﬂ ow; if necessary, replace with larger regulator.

C. Pressure loading system pressure restricted. C1. Clean restriction or bleed oriﬁ ces.

C2. Clean ﬁ lter(s).

C3. Clean loading pressure control device.

D. Faulty loading pressure control device. D. Replace/repair loading pressure control device.

6. Leakage at body/cover ﬂ ange.

Possible Causes Remedies

A. Body bolts not torqued properly. A. Torque to proper value (see Section VII, F-11).

B. Pressures may be too high. B. Consult factory.

7. Leakage across seat.

Possible Causes Remedies

A. Contamination (debris) in regulator. A. Remove internals, clean, & replace sealing and seating elements. *

B. Oversized regulator; valve plug operates

directly next to seat.

B. Check actual ﬂ ow conditions; resize regulator for minimum and maxi-

mum ﬂ ow; if necessary, replace with smaller size regulator.

* Seat leakage may be diagnosed when a failure of the dynamic side seal has occurred. Inspect both potential internal leak paths.