Jordan Valve Mark 5108 Series Back Pressure Regulator - Manual (Page 4)

B. Main Valve fails to Close:
1. Upstream pilot system ball valve (A) closed.
Open as required.
2. Strainer (5) clogged. Clean as required.
3. Closing speed control adjusted fully closed.
Open as required. See Adjustment instructions.
4. Pressure relief pilot (2) adjusted too far counter-
clockwise. See Adjustment instructions.
5. Close the downstream pilot system ball valve
(6B).
(a) If valve closes, proceed to Step 6.
(b) If valve remains open, proceed to Step
7.
6. Pressure relief pilot (2) stem binding or seat
badly deteriorated. Disassemble pilot
and determine cause.
7. Close both pilot system ball valves (6A and 6B)
and loosen a pipe plug in the main valve
bonnet. A continuous discharge of fluid
from the loosened plug indicates that the main
valve diaphragm is ruptured. Replace
diaphragm.
NOTE: Certain valves, predominantly those in fuel
service, are assembled "fail closed." In this case, a
ruptured diaphragm would keep the valve from opening,
rather than keep it from closing. To determine which type
you have, examine the "bridgemark" cast into the side
of the main valve body and compare it with the diagram
below.
8. Main valve stem binding or object caught in
valve. Disassemble valve and determine
cause.
C. Main Valve Opens and Closes, but Leaks
When Closed
1. Pressure relief pilot (2) adjusted slightly too low.
See Adjustment instructions.
2. Close downstream pilot system ball valve (6B).
(a) If the leak stops, the problem is in the
pressure relief pilot (2), likely a
damaged seat. Disassemble
pilot and determine cause.
(b) If the leak continues, the problem is
in the main valve, likely a damaged seat.
Disassemble valve and determine
cause.
M
ark
5108 S
erieS
B
ack
P
reSSure regulating
V
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Jordan Valve, a division of Richards Industries
3170 Wasson Road • Cincinnati, OH 45209
513.533.5600 • 800.543.7311 • 513.871.0105 (f)
[email protected] • www.jordanvalve.com