Nonsense # 2 ) The blackmail after filling is authoritative. The coerce of propane vaporization ( a gas over some sum of pure liquid ) is a function of temperature. only. There ‘s a graph. In the tank the molecules of propane go back and forth between the liquid and the flatulence. There ‘s a balance reached between the vaporization and condensation rates. The dehydration pace depends on temperature but the condensing rate does n’t so the libra depends on the temperature. The warm it is, the higher the pressure of the vaporization. If there is any sum of liquid and any total of gas, that graph is obeyed. Nothing you can do will change the vapor blackmail. All tanks containing between 1 % and 99 % liquid have the same press if they are at the same temperature. Nonsense # 3 ) The relief valve is cautiously calibrated at the factory. It ‘s set to a quite high blackmail. It ‘s there to stop the tank car from rupturing. It ‘s a steel tank car. That pressure is high. It ‘s somewhere around 360-480 PSI. That ‘s something like 25 bar if you ‘re looking at the vaporization pressure graph. Put the tank in boiling water and the pressure will want to rise to double that. ( The valve should open to prevent that ). The tanks are required to have a minimal abound pressure of 960PSI so they are actually designed slightly higher. Call it 1200PSI. There ‘s a wide remainder between those pressures. Valid Concern # 2 ) If the atmospheric pressure relief valve opens it might not reseal well.
These tanks are meant to be discarded after a one use. The valves are c*ap. They are n’t meant to open and close repeatedly sol when they do clear they have a closing-failure rate. Over prison term a humble leak can release the entire contents into an insert area like your torso or a memory cabinet and you ‘re facing Valid Concern # 1. THE REAL PROBLEM WITH OVERFILLING If you fill the tank to 100 % with liquid, there is no vapor and the graph above no longer applies. I do n’t have the accomplished data on the physical properties but Wikipedia says that the volume wants to expand 1.5 % for each 10 °F. ( there should be some pressure/compressibility terms decreasing that for our position ). If you about fill the tank then warm it up the liquid will expand, shrinking the gas until you have liquid press in all directions and then the press can rise very quickly. How many 10 ‘s of degrees are between a frosty tank and the temperature in your car parked in the sun on a hot summer day ? Looks like 80-85 % full is about right. then Nonsense # 4 ) the tank car will shred sending shrapnel in all directions. When an explosive bursts a container send shards, it is, at its center, an expanding testis of high pressure gasoline. Like a compressed give, when you release it, parts fly approximately.
A 100 % broad tank though is filled with liquid. When the liquid ruptures the tank ( if you defeat the safety relief valve ) it ‘s filled with fluid and it ‘s just going to tear the tank and leak out. The fluent propane will want to change to a flatulence and throw bits around, but it needs heat energy to do that. It gets that heat from the liquid so the liquid cools down and that lowers the vaporization pressure. alone some can evaporate before the bulge liquid is besides cold to worry about. Its bomb-like-ness is express, but again you ‘re binding to Valid Concern # 1 ). My actual contribution : Put a patch of thwart magnetic tape over the safety valve to keep dust out of it. That might help it not leak. many of my numbers came from this report