question about filling our propane tanks

[peppster66]

Hi, went out tonight and wanted to top up my propane tanks before we head out this weekend for a 2 week holiday, when the gentleman was hooking up the main fill hose, I asked if we needed to open the the small release valve at the top, as I thought we were supposed to do, he said It wasnt necessary, and continued to fill my tank, my question is this, is it proper procedure to open that valve while filling the tank, it was my understanding that by doing so, your getting more liquid than gas, and able to top it up, with no issues of clogging your pressure regulator valve,,any feedback would be greatly appreciated,,,, thank you,,,,,

[avanti]

Well, I don't know the details, but I did once have a guy destroy our regulator by filling w/o opening the relief valve.

[gregmchugh]

Yes, it is proper procedure to open the small relief valve but my understanding was that it is done to insure that the tank is not overfilled if the automatic overfill shutoff does not operate correctly. If liquid comes out the relief valve before the auto shut off happens I think it indicates that the auto shut off is not working properly. Without the relief valve open you could get an overfill if the auto shut off failed and liquid into the regulator which I believe will damage it. With ours, the auto shut off always occurs before any liquid comes out the relief valve.