Re: LP setup without reg?
First of all what type of gun are you working on?
I'm assuming a spyder or spyder clone. Its not possible to do an LP spyder without a regulator. Without a regulator you will be running at the pressure output of the tank with is usually 800-900psi, which is far from low pressure.
A PMI regulator would work but there are many other better regulators out there that I'd suggest. I'd either go with a Bob Long Torpedo reg, a Custom Products reg, a WGP Ergo reg or a Palmer's Stabilizer.