If engine heat is a problem for Propane why do the forklift makers mount the tanks on top of the engine on the hood ? mine was mounted close to the engine compartment and never vented and I live in AZ also,you guys never saw a farm tractor with a 100 gal propane made into the hood setting on top of the engine ?
FWIW that is the reasoning behind the 80% fill on propane tanks to prevent the venting from heat
All of that is true. All tanks have void that is dedicated to expansion. They also have a overpressure vent and my vents are threaded so that I could attach a hose. As a general rule of thump, propane tanks "should" not be mounted near a heat source and be away from batteries.
Fork lifts are a different animal. While we us propane as gas, a forklift uses it as a liquid. Even our tanks get cold and can even get a frost layer. The forklifts, in heavy service, can freeze everything. They use hot engine coolant to heat the propane in the carb and the pipes. Their tankl also gets really cold so mounting it "near" the heat source is advisable in that case. Didfferent situations, uses and rules.
I think the logic of the reg about running the vent to the rear is that if it vents and you are underway then an ignition of the venting gas will pose little threat at the rear. I am groping for the logic in that.
I have seen a RV destroyed by a propane line rupture. According to my friend, he was standing in the living room of a old 26 foot S&S. He heard a whooump and turned to see flames coming from under the sink. The sink was across from the door and he said he dashed out the door after taking no more than three steps. Flames singed his back and hair as he jumped out. He was certain that if he had been a mere few feet further from the door he would not have made it. he said that after running maybe 29 feet away he turned and saw to his horror that the interior was an inferno. it took seconds. Propane is extremely dangerous. There are a lot of regs and they are pretty anal about every little detail. it is because of this fear and respect that we have so few tragedies with the stuff. Be careful. Find out what the rules are and follow them....to the letter. It isn't really relevant if you don't understand why a reg is there or how many folks you have seen get away with doing it another way. None of that matters cause we tote some precious cargo around and we need to make sure we give them the very best our efforts can provide.
I have propane "everything" and I wish I had had a propane fueled generator.
My very best wishes for your safety,