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XI. General Planning for Maintenance
A 12 month maintenance interval is recommended for general service conditions. For severe
service applications, a 3 to 6 month inspection and test interim may be more appropriate.
The specific plant's operating and service history will better determine this frequency. BHGE
encourages preventive maintenance.
The 2900-40 series Pilot Operated Safety Relief Valve (POSRV) is easily maintained. Normal
maintenance usually involves:
•
Removal of pilot valve from main valve
•
Disassembly of both the pilot and main valve
•
Cleaning
•
Component Inspection
•
Parts Replacement as Needed
•
Reassembly
•
Setting, Testing and Resealing the Valve
Occasionally, remachining the nozzle may be necessary to extend the service life of the valve.
Keep all parts for each valve separated to ensure replacement in the same valve.
Note: Insure there is no pressure in the inlet of the valve before attempting to remove it from the
piping system.
XII. Recommended Installation Practices
A. Mounting Position
The POSRVs should be mounted in a vertical upright position (in accordance with API RP 520).
Installing a pilot operated safety relief valve in any position other than vertical (±1 degree) will
adversely affect its operation as a result of induced misalignment of moving parts.
A stop valve may be placed between the pressure vessel and its relief valve only as permitted by
code regulations. If a stop valve is located between the pressure vessel and POSRV, the stop valve
port area should equal or exceed the nominal internal area associated with the pipe size of the
POSRV inlet. The pressure drop from the vessel to the POSRV shall not exceed 3% of the valve's
set pressure, when flowing at full capacity.
Ensure the flanges and sealing faces of the valve and connective piping are free from dirt,
sediment, and scale.
Ensure all flange bolts are drawn evenly to prevent distortion of the valve body and the inlet
nozzle.
Position the POSRVs for easy access and/or removal so that servicing can be properly performed.
Ensure sufficient working space is provided around and above the valve.
© 2019 Baker Hughes, a GE company. All Rights Reserved.
Do not interchange
parts from one valve to
Decontaminate or clean
if necessary before
pretesting or disassembly.
Safety and environmental
precautions must be taken
for the decontamination
or cleaning method used.
Consolidated 2900-40 Series POSRV Maintenance Manual | 21
another.
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