On Fri, Feb 4, 2011 at 12:14 PM, graham foulkes wrote= : > Hi > Maybe a smaller separate compressor unit to provide 'clean' i.e. oil/wate= r > free air for the processes that require it could answer your needs. I wou= ld > suggest looking at Gast oil free vane compressors. These have dry lubrica= ted > graphite vanes as the rotating elements. This approach would give you bul= k > 'shop air' from an oil lubricated compressor and 'clean' air from a separ= ate > compressor. Of course, you will still have to use filters and traps to > minimize water build up in air lines and reservoirs, usual good housekeep= ing > practices. > In answer to you question, "am I just being over cautious"? No way! If th= ere > is a chance of oil getting into your equipment, it will. Even the best oi= l > lubricated compressors will occasionally spit oil, and oil mist is presen= t > in all types of oil lubricated compressors. Good clean air needs filtrati= on > and trapping and relies on good maintenance and regular blow downs and > filter changes. Another alternative is a diaphragm type compressor, but > these do not usually supply shop pressures or volumes, more used as paint > spray units. Back in college I was (sort of) in charge of a small clean-room facility that used compressed air for actuators and things. I installed an automatic water-drain valve at the bottom of the water separator. It was pretty nifty for me because I was the only one who remembered that the trap had to be drained once in a while. It was full when I started working in there. I probably got the valve from McMaster-Carr. I did a quick search but didn't see it. --=20 Martin K. --=20 http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .