part of the weirdness is the tank has been in use for several months.

On 10/3/2012 11:15 AM, Mike S wrote:
> On 10/3/2012 11:32 AM, Stuart MacMillan wrote:
>> Problems like this are maddening!  Bad auto stop valve or bleed valve
>> that
>> doesn't vent are the only things that can prevent filling.
>
> It's more likely that the tank simply needs to be purged of air, as
> already mentioned.
>
> When the tank has nothing but propane in it, it can be easily filled.
> Pumping liquid propane in increases the pressure, and the existing
> propane gas in the tank turns to liquid, making room. For a tank at 80F,
> that pressure is about 130 psi.
>
> If you try to fill a tank which has air in it, the air simply
> compresses, and pressure goes up. New tanks are often shipped with
> compressed air in them, so you can't push much propane in before the
> pressure gets too great to be able to pump more.
>
> Hence, the need to purge the air from the tank before first use.
>