First of all, the air compressor selected must be oil-free, that is, what is compressed during compression is not an oil-air mixture, but pure air.
The compressed air that comes out must then undergo water separation and air purification. The equipment used includes cold dryers and various purifiers. In particular, the purifier must be of medical grade, and then some air supply pipelines and Gas storage tanks and the like are made of stainless steel or copper.