Michelle.S wrote:
Well they can explode. Couple years ago just South of Sebring Florida at a Propane Tank Storage Facility they had a fire and some tanks we found 1/2 a mile away after they exploded.
Put a sealed canister of anything in a hot enough fire and it can explode. Sure, a propane cylinder will have a more exciting explosion than a sealed cylinder of water, but build up enough pressure, and the sealed cylinder of water will go. That is a lot different than a propane cylinder that is compressed in an accident with no flame to ignite it. I am not saying it can't happen, but your example does not apply to this scenario. Mythbusters did a show trying to get 20# propane cylinders to explode in flames. The only way they ever managed to do it was to shoot it with incendiary ammunition. Even then, they had to shoot it twice. The first shot ruptured the cylinder and it started spewing propane gas. The second shot, the incendiary round ignited the gas. The first incendiary round went completely through the cylinder, leaving holes on both sides, without igniting the propane. Non-incendiary ammunition would not ignite the propane, no matter how many times they shot the cylinder.