If you have a lubricated reciprocating or rotary vane air compressor,
you’ll need to change the oil from time to time to keep it working properly.
Nice Compressor recommended schedule is generally three months, subject to the date of manufactureing that particular product.
For a all typr rotary screw compressor, you have to change the oil every 4,000 to 8,000 hours
depending on the type of oil employed.