Of course we like 29.92 inches Hg over 14.7 psiHi,
Actually we got that wrong...
The charts on this page give the absolute and gage vapor pressures for propane
At -44F (boiling point of propane), it produces 14.7 psi (one atmosphere) of absolute pressure and 0 psi gage pressure.
By about -30F its up to 20 psi absolute and about 6 psi gage.
So, its going to be hard to get propane cold enough where it won't produce enough pressure to work -- unless its contaminated with water or something else.
😜I thought you guys liked 760 mm