One of the conditions for trouble-free operation of the screw compressor is timely oil change. This equipment is characterized by an optimal ratio of ease of operation and durability. The working part of the unit consists of a compression chamber, a pair of specially shaped screws and a motor.
The life of a screw compressor depends on the quality and regularity of oil changes more than other types of compressors. Increased requirements to the lubricant properties are due to the specifics of the equipment operation. Air injection is performed by a pair of screws, during the rotation of which the cavity between them moves from the suction point to the compression chamber. The screws are not in contact with each other, but have a microscopic gap between them. During operation, this gap is filled with an oil film, so there is no air leakage.
During compressor operation, the composition of the oil gradually changes. Wear products, dust and moisture from the incoming air get into the process fluid. This change in composition leads to a deterioration of the technical parameters. For screw compressors, timely oil change is one of the most important operating requirements.
How often oil changes are required in a screw compressor
The standard service life of the lubricant is 2500 to 3000 operating hours, but at least once a year. It is not recommended to exceed this time. For some models, other times may be specified by the designer and must be indicated in the operating manual.
Procedure for changing the oil in the screw compressor:
- Make sure that the system and receiver pressure is "0" and disconnect from the power supply.
- Remove the compressor casing wall.
- Visually check for oil leakage, condition of radiator, tightness of fasteners, belt tension, air filter clogging. If any problems are detected - eliminate them.
- Completely drain the entire volume of lubricating fluid. The old lubricant should be drained through the oil drain valve. The operator should make sure the system is empty.
- Replace the oil filter and separator filter (oil separator). As a rule, the air filter is also changed during this service.
- After that, new oil is poured in the amount recommended by the manufacturer.
- Check the oil level through the oil gauge sight glass
- After checking whether the oil filler holes are closed, the compressor should be switched on for a few minutes. Then check the oil level again and top up if necessary.
Important: Only the oil grades recommended by the manufacturer may be filled. Do not mix different grades. If the compressor has not been used for a long time: before starting the compressor after oil change, add oil to the screw pair (through the air filter connection or otherwise).