Propane Tank Safety: Overfilled?


So I recently picked up a new-to-me FWC Eagle :wings:, and last night, filled the close-to-empty propane tank. The guys at the filling station started off filling it vertically (tank standing upright) but decided that for one reason or another, it didn't fill as full as it should have. They then turned it on its side and filled a little more. This was all well and good, until I re-installed the tank in the camper (without plugging it back into the regulator) when I read the label on the top of the tank. "Fill only in the upright position" :Wow1: I've been searching google all morning trying to figure out how to find out if the tank is overfilled, and whether or not I can safely vent any excess.
I understand that the tank needs about 20% room for expansion, and the "fill only in..." tag says that it can be bled by turning the vent valve until white liquid (propane) stops bubbling out, however it doesn't say whether this should be done upright or on its side. Does anyone have any experience with this?



Expedition Poseur
If you over-fill it, you should bleed it in the orientation that it was designed to be filled -- in your case, bleed it upright.

As a side note - you can get a general idea of how full it is by pouring hot water over the tank. You'll be able to feel a temperature change at the point where the propane goes from gas to liquid (the 'level'). After pouring the hot water over it - the top portion of the tank (where the propane is in the gaseous state) will be warmer than the bottom portion (where the propane is in its liquid state).
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Expedition Leader
If the tank is relatively new, it should have an Overflow Prevention Device. You have an OPD valve if the valve handle is triangular. If you have an OPD tank, it's pretty much impossible to be overfilled.

If you have an older tank, it could be overfilled. You can always (upright and away from flames/sparks please) let out about 20% of the tank weight to be absolutely certain, at the cost of a gallon of propane you already paid for :(

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