File Name:
IOM BC-73Q-P (1.5in-4in)
Rev. 01
Prepared By:
RC
Date:
03/17
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The information contained in this document is subject to change without notice. BERMAD shall not be liable for any errors
contained herein. All Rights Reserved. © Copyright BERMAD Control Valves.
Model BC-73Q-P
IOM
PC-3Q
4
1
2
3
705
4A
S
Control Loop Diagram
Troubleshooting
Symptom
Possible Cause
Solution
Valve Fails to Open
•
Insufficient inlet pressure.
•
Pipeline isolation valve(s) closed.
•
Excessive relief pilot PC-3Q spring
compression.
•
Cover/body tap/plumbing clogged.
•
Check/create inlet pressure.
•
Open isolation valve(s).
•
Readjust pilot PC-3Q. See step 5 of the
commissioning instructions.
•
Clean cover/body tap/plumbing.
Valve Fails to Close or Regulate
•
Filter 4A clogged.
•
Insufficient relief pilot PC-3Q spring
compression.
•
Debris trapped in main valve.
•
Diaphragm in main valve leaking or
diaphragm assembly loose.
•
Remove in-line filter 4A and clean
screen/body taps re-installing w/dot
mark facing upstream.
•
Readjust pilot PC-3Q. See step 5 of the
commissioning instructions.
•
Remove actuator assy. to inspect seat
area/verify valve stroke/remove debris.
•
Remove a small cover plug at valve
cover. Continuous flow indicates
diaphragm leakage. Inspect, tighten,
and/or replace Diaphragm.
PART LIST
4A
Control Filter
S
Limit Switch Assembly
PC-3Q
Relief Pilot, Quick Type
705
Main Valve
