Originally Posted by Ron in BC
Been filling my own for years using a spare 100# tank, inverted and left in the sun to warm up.
There are reasons why propane cylinders have a top and a bottom - among them, the pressure relief valve is on the top, and connected to the vapour space so that an overpressured cylinder does not spew liquid propane. If leaving a tank to warm up and increase pressure, leaving it upright would be safer. If you insist on inverting a vapour tank instead of using a proper liquid-service tank, it makes sense to me to at least not invert it until necessary to get liquid out of the vapour service port. Something like a forklift tank or vehicle fuel tank would avoid this issue.