An air compressor is an important machinery in the ship’s engine room which supports several other systems, including the main engine. However, the compressor is one machine which requires constant monitoring and maintenance in order to ensure it runs smoothly. Though a number of safety devices are provided on the compressor, it is only prudent to take all the necessary precautions that are required for the smooth running of the compressor.
For understanding common problems with air compressors, it is important to know all the different parts of the system. One must also know all important checks that are required to be made before operating the compressor. As a marine engineer working on ships, you should be able to understand and troubleshoot some of the common problems associated with the marine air compressor. Mentioned below are five such common problems.
1. Compressor Capacity is Low:
This is one of the most common problems seen on all types of ships. Often, compressor capacity can go low or reduced if it is running for a long time and eventually it is unable to cope up with the air demand.
Main reasons for this problem are:
- Leakage in discharge and suction valves
- Fault or leakage in the unloader
- Leakage from the relief valve
- Increase in bumping clearance (Read more about bumping clearance here.)
- Wrong setting of compressor auto cut-in and cut-out (too close)
2. Oil Carry Over in Air:
If the compressed air in the system is carrying oil, would be mainly because of the following reasons :
- Oil-water separator is not working correctly hence oil is being carried to the air receiver
- The cylinder lubrication is adjusted at high quantity, leading to carryover of oil with air
- The auto drain is malfunctioning
3. Excessive Vibration and Noise:
If the compressor is generating too much noise and vibration, it can be because of the following reasons:
- Loose pulley, flywheel, belt, belt guard, cooler, clamps or accessories
- Lack of oil in the crankcase
- Piston hitting the valve plate i.e reduced bumping clearance
- Compressor holding down bolts are loose
- Compressor foundation chocks have worn out
4. Overheating of Discharged Air
If the temperature of the discharged compressed air is high, it can be because of overheating caused as a result of the following reasons:
- Chocked or dirty intercooler tube
- Cooling water pump capacity decreased or insufficient
- The atmosphere at air suction of the compressor is hot
- No forced ventilation for fresh air near the compressor
- Damage in the head gasket
- Chocked air suction filter
- Valves of 1st or 2nd stage leaking
5.Milky Oil in the Crankcase
If there is an accumulation of milky coloured oil in the crankcase, it can be because of the following reasons:
- Water leakage from cylinder liner
- Water leakage from the jacket
- Oil running hour is over
These are some of the most common problems that are found in continuously running air compressors onboard ships.
Do you know any other common compressor problems? Let us know in the comments below.