Proper care of a compressor lubrication system includes the following:

- Keep the oil at a normal level in the reservoir at all times to maintain proper oil temperature.

- Change crankcase oil periodically, and at the same time clean and flush the crankcase and clean the oil filter.

- Maintain proper lube-oil pressure by keeping the oil pump in good working order and adjusting the bypass relief valve.

- Keep the oil cooler free from leaks (since pressure on the water side exceeds that of the oil) to prevent oil contamination and emulsification.

- Properly adjust the lubricator for the specified quantity of oil feed.

COOLING SYSTEM

Proper care of a compressor cooling system includes the following inspections and maintenance procedures:

- Periodically inspect the intercoolers and aftercoolers.

- Remove collections of gummy oils or tarry substances from the cooler tubes by washing tube nests with a suitable solvent and drying them thoroughly before reassembling.

- Correct any leakage in tube nests to prevent leaks of water into the compressor while secured or leaks of air into the water side during operation.

- Inspect and clean the cylinder water jackets periodically with a cleaning nozzle.

When filling the cooling water system after the compressor has been drained, open the water inlet slightly to allow the water to rise slowly in the cooler shells and water jackets. Vent valves fitted to the water spaces should be opened to permit entrapped air to escape and to remove any air pockets.

CONTROL DEVICES

Because of the great variety of regulating and unloading devices used on compressors, you will have to consult the manufacturers technical manual for information regarding the adjustment of these devices on particular compressors.

If a control valve fails to work properly, it should be taken apart and cleaned Some valves are fitted with a filter filled with a sponge or woolen yarn to prevent particles of dust or grit from being carried into the valve chamber. These filters remove gummy deposits from the oil used in the compressor cylinders. When repacking, use only genuine wool. Cotton will pack and stop the airflow. Relief valves are very important for safe compressor operation. They should be set as specified by the manufacturer and lift-tested by hand each time the compressor is placed in operation. To check the setting periodically, test by raising the pressure in the spaces to which they are attached.

SUMMARY

Since an Engineman may encounter so many types of compressed air systems, air dryers, and air compressors both ashore and aboard Navy vessels, this chapter presented only general procedures and facts. To maintain, repair, and overhaul specific compressed air systems, air dryers, or reciprocating air compressors, you must refer to the manufacturers technical manuals. A definite preventive maintenance schedule with frequency and assignment of responsibility is required. You should have the manufacturers manual handy to establish minimum requirements and to follow its recommendations for maintenance.