0 to 30psi and 0 to 60psi is ideal, but you can use one up to 0 to 200psi. Past that, they may be worthless for our use.I've been looking for a used regulator and have been wondering if the outlet pressure makes a big difference. I know that I want a two stage regulator, but but I've seen models with max outlet pressure anywhere from 30 to 500 psi. Most of the regulators that you guys seem to be using are usually 30, but if I find a good deal on one with 500 psi max outlet pressure, should I snap it up?
Look for regulators that have a CGA-320 (for CO2) or CGA-580 (for inert gas, but you can either use an adapter or exchange the stock nut and nipple for a CGA-320 or high purity regulators that have stainless steel diaphragms (these are fine if the gas service pressure isn't too high).
Anwar, that is mentioned in the Victor link, sells Victor high purity, chrome plated, stainless steel diaphragms regulators that have a CGA-320 nut and nipple and also a 1/4" MPT x 1/8" MPT adapter. He is good to work with. Several people have ordered from him.