This thread offers for info on filters.

http://www.everlastgenerators.com/fo...siccant+filter

I switched to the HF mini inline desiccant filters based on price and cut quality (I still have a larger dryer/filter at the compressor). I put a regulator right before the filter, right at the back of the plasma cutter, and note 90 PSI rating). I was quite pleased when they worked as well as anything similar I tried. I caught them on-sale once for $4.99 each and stocked up (normally $7.99). The brand name and HF have only on difference I can see, but they work quite well (brand name is better built of course).

http://www.harborfreight.com/inline-...ter-94733.html