Because of the great variety of regulating and unloading devices used on compressors, you will have to consult the manufacturer s 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. 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 manufacturer s technical manuals. A definite preventive maintenance schedule with frequency and assignment of responsibility is required.