I plan on using one single regulator to drop the 175 psi tank pressure down to a system pressure of around 100 psi. I cannot think of any reason why I would need more than 100 psi, never have in all my years of mechanical work. Anyhow, I already have the regulator, sitting in the box waiting for me to install the system. I bought a Wilkerson with 1" pipe thread fittings and capable of around 500 CFM, overkill I know, but it will make a good system regulator, right off the tank, and the price was right from
www.surpluscenter.com
Some people I suppose perfer to have 175 throughout the system and regulators and filters at all drops, more expensive and I intend on using one inch pipe for the loop around the shop, though I may close the loop at the far end (which will be largely unused anyhow) with something smaller, possibly 3/4 to save money. (more like a horseshoe around the shop with the smaller pipe connecting the ends).Charles