A: Centrifugal, reciprocating, and rotary screw compressors have all been used in jet milling operations, with the latter being the most common. It is recommended that the compressor deliver a minimum of 100 psig to a maximum of 140 psig to the mill. The higher the grinding pressure, the finer the grind.

The quality of the air is at the discretion of the customer. Oil-free or food-grade lubricated compressors may be necessary for pharmaceutical, specialty chemical, or pigment applications. Most installations have a compressor package, which consists of a compressor with an aftercooler, refrigerated or desiccant air drier, coalescing filter, and a high-pressure receiver. With a refrigerated dryer, a typical dewpoint should be in the 35°-39° F range. Air dryers are not essential but are recommended for preventing condensation and eventual product build-up within the system.