SpudFiles

three questions:
1) what type of propane regulator do you recomend
2) how do propane regulators work
3) how much pressure is present in a propane torch cylinder

1.) I recommend a simple air regulator. Accurate enough for a combustion propane meter and cheap.
2.) Regulators work by a spring-loaded diaphragm. The spring is adjusted b the knob, and the amount of compression on the spring determines the cracking pressure of the diaphragm, regulating the pressure on the output.
3.) That depends on the temperature of the gas in the cylinder. Take a look at the wiki for the vapor pressure/temperature chart.