6
IOM-1049
Possible Cause
Remedy
A.
Pilot diaphragm failure.
A1.
Disassemble and check pilot diaphragm. Replace if re-
quired.
3. Vapor leaking from pilot spring bonnet.
4. Seat
Leakage
SECTION VI
VII. TROUBLE SHOOTING GUIDE
Possible Cause
Remedy
A.
Sense line is clogged.
A1.
Check sense line and sense port for blockage. Clean as
needed
B.
Incorrect set pressure.
B1.
Adjust set pressure screw to proper set pressure.
C.
Pilot or actuator diaphragm failure.
C1.
Disassemble and check diaphragms. Replace if required.
D.
Loss of external air/N2 source for air/N2 assist pilot. D1.
Check external source.
1. Model 1049 opens below set point.
Possible Cause
Remedy
A.
Incorrect set pressure.
A1.
Adjusting set pressure screw to proper set pressure.
B.
Pilot exhaust plugged.
B1.
Check pilot exhaust for blockage. Clean as needed.
C.
Sense line clogged.
C1.
Check sense line and sense port for blockage. Clean as
needed.
2. Model 1049 will not open.
Possible Cause
Remedy
A. O-ring seat has failed.
A1. Disassemble and check o-ring seat. Replace if required.
B. Foreign particles trapped between seat and seat
plate.
B1. Check and clean as needed.
C. Sense line clogged.
C1. Check sense line and sense port for blockage. Clean
as needed
D. Back pressure higher than tank pressure.
D1. Vent operating properly.
