Sumitomo HC-4A, Technical Manual

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Maintenance
41
Leaks at welded joints require special skills to repair. Consult a SCAI Service Center.
Replacing worn or damaged parts can repair leaks at the self-sealing couplings. Vent the
compressor before beginning to disassemble it.
Tightening the coupling frequently stops leaks at threaded joints. Continued leakage after
tightening requires coupling repair. Install new O-rings or Teflon tape as required.
To repair a compressor coupling:
1. Stop the compressor and disconnect the power to the compressor.
2. Disconnect the gas line from the compressor coupling to be repaired.
3. Install dust caps on all disconnected gas couplings except the one to be repaired.
4. Remove the compressor’s cover.
5. Use the Venting Procedure to Vent to Atmospheric Pressure to discharge all gas from
the
compressor. This procedure includes disconnecting
the
adsorber to prevent venting it.
6. At the coupling to be repaired, hold the stationary part with one wrench. Use a second
wrench to disassemble the coupling.
7. Remove the old O-ring.
8. Wipe the O-ring groove to be sure it is clean. Lightly coat a new O-ring with vacuum grease.
Install the new O-ring.
9. For a threaded joint sealed with Teflon tape, remove all old tape and apply new tape.
10. Reassemble the coupling using two wrenches.
11. Perform the Gas Cleanup procedure.
AVOID CONTAMINATION. A leaking coupling on an adsorber should not be
repaired in the field. Consult a SCAI Service Center. Venting the adsorber will
introduce contaminants to the system that cannot be removed in the field.
NOTE
To repair a manifold assembly coupling, vent the manifold to atmospheric
pressure using adapter fitting P/N 266395C or 255919B2. Follow steps 6 to 11
above.
Coolant System Leak Repair
NOTE
Coolant system is sealed. For normal operation, no filling or draining
maintenance is required.