4. Operational failures

Fault symptom Possible cause Remedy

Fault symptom Possible cause Remedy

Fault symptom Possible cause Remedy

A

The compressor has poor capacity and/or does not produce full pressure.

Dirty, worn or damaged valves.

Inspect and clean all valves.

Replace defective parts.

Piston rings have stuck in the ring grooves, or are damaged/broken.

Disassemble the rings. Clean grooves and rings and replace defective parts. Reassemble, applying oil to the cylinder walls.

Leaking safety valve.

Replace safety valve.

Defective cylinder head gasket.

Replace gaskets.

Clogged air filter.

Clean filter.

B

LP safety valve blows.

HP suction valve damaged or dirty.

Inspect and clean valves and replace defective parts.

Leaking seal in HP suction valve.

Replace seal.

LP safety valve defective or damaged.

Replace safety valve.

C

HP safety valve blows.

Stop valve in the air line is closed.

Open the stop valve.

Clogged non-return valve.

Remove and clean non-return valve. Replace defective parts.

HP safety valve defective or damage

Replace safety valve.

D

Valves need overhauling too often.

Overheating.

Check cooling water circulation and temperature. Inspect and if necessary clean coolers.

Polluted intake air.

Inspect intake filter

Poor lubricating oil.

Change oil grade.

Valve clamp bolts not tightened enough.

Tighten the clamp bolts to the correct moment.

E

Overheating and/or abnormal noise in crankcase.

Defective bearings.

Inspect bearings and check clearances.

Low oil level or condensation in oil.

Drain and clean crankcase sump, fill with new oil.

Jamming crankshaft bearing.

Check bearing clearances. Replace defective parts.

F

Piston overheating and friction.

Incorrect fitting of piston or crosshead bearing.

Replace defective parts, check piston clearances, ring clearances and crosshead bearing.

Cooling malfunction.

Check cooling water circulation and temperature.

G

Increased oil consumption

Worn piston rings.

Replace piston rings.

Leakage.

Check the exterior of the compressor.

H

Oil emission from crankcase ventilation.

Defective or worn piston rings.

Remove and check piston and if necessary replace defective piston rings.

Defective ventilating valve.

Replace valve.

I

Ruptured bursting disc.

Cooling water pressure too high.

Check that pressure is within the specified limits.

Cooling water temperature too high.

Check that temperature is within the specified limits.

Pressure pulses in cooling water system.

Determine what is causing pulses and eliminate.

J

Worn rubber lamina in the coupling between compressor and motor.

Poor alignment of compressor and motor shafts.

Correct alignment of coupling.