Extra propane tank

Clay L wrote:
I have never seen a propane tank that was filled properly (to 80%) vent due to a normal temperature increase.

Does anyone know what pressure is required to cause venting? With that info one could use the Ideal Gas Law to calculate the temperature at which venting would occur.

From my design engineering days for the automotive environment I know that under dash temps can reach over 200F in direct sun in the AZ desert. (black dash, black car)

CO law allows propane tanks under 40 pound capacity to be transported in a car or car trunk when secured in an upright position. I would expect a closed bay compartment would be the same.

That being said, a defective valve that leaks would not be a good thing in an enclosed area.

The vent pressure of most LP tanks is 250 psi. Some are built to a comparable standard and have a rating of something around 300+/- psi, but were intended for propylene service, not propane. I mention this only because I have seen those tanks repurposed by unknowing individuals and it causes an undue risk in propane service due to the higher relief valve setting.


I find the general paranoia about propane stored in unvented compartments interesting when we consider that nearly every coach or trailer has pressurized LP lines running throughout them and we rarely have anyone discussing the leak potential of those lines. Most of us operate our refers while traveling and would not consider shutting off the LP supply to avoid those potential leaks.

I would worry more about vibration causing a line leak than a venting tank in storage, particularly one that is out of the direct sunlight.