Hello Derik,
At first I thought it would be a really difficult thing to regulate the correct amount.
What you discover after the first 10 or 20 thousand miles (300-1000 hours?) is that it just takes a tiny bit of propane, and for a constant load, maybe once or twice a week you turn it on for a few hours.
The Chev 6.5 diesels have a high pressure regulator, and a needle valve, and an electrically operated solenoid, so when the throttle is more than 1/4 or so down, a lever switch actuates the solenoid, which turns on the gas flow. At the far end is a "needle" on the inlet, drilled and tapped after the turbo, which provides for final regulation. In other words, 25 thousandths only allows X flow at 25 PSI. (only an example!) A 5 gallon propane bottle usually lasts 500 miles or so when pulling the 5th wheel (21,000 pounds total with the P/U, 9-10 MPG or so without propane, 13-14 or so with.) properly adjusted, you don't even know it is on EXCEPT that it pulls hills about 1/2 gear higher, and instead of being in third gear up hills at 35, you go in fourth at 55 a lot of the time.
When pulling, I had the needle valve in the cab for adjustment for a year or so, but it is just not necessary.
For a fixed load, slow-speed diesel, it is a lot simpler.
What fuel(s) are you using?
