RIX's non-lubricated air-cooled compressors are available in one to four stages at pressures up to 10,000 psig. These compressors all have distance piece separation of the compression area from the lubricated lower ends to ensure clean gas compression. The 4VX has a force-fed lubrication system for the running gear while the 2V is splash-lubricated. RIX's patented spiral teflon piston rings are used in both designs. Special materials are sometimes used for hydrogen and bone-dry nitrogen compression to high pressures.