I am surprised that even tho I was the 1 to bring up the subject of
purging(let no tank be purged before its time), no 1 ripped moi for stating
that the westy propane tank holds 3.5 gallons @ 80% full.(should be 2.5
gallons+-?)  I mistated that as I had just refilled 2 BBQ sized tanks that
day & was dazed & confused about which tank I was talking about!

YMMV,

Mr. BZ-I feel like Mittens, so many facts so few remembered
correctly-LOL-no flames please, propane involved!

On Wed, Oct 3, 2012 at 11:12 PM, David Vickery <david_vickery@yahoo.com>wrote:

> You're right Dennis (and Mike).  Unless the tank is opened it should not
> get air inside.  My bad.
>
> Basically what I said was wrong.  I spent a little while educating myself
> about purging propane tanks.  Seems like the the biggest real life problems
> from not purging are air/lp mix that doesn't burn well, regulatgor freeze
> up from the water vapor in the tank, odorant fade and over pressurization
> (which will go out the relief valve).
>
> The interesting thing I learned is they can't purge a tank at the fill
> station, it needs to be purged with LP vapor not liquid so it needs
> additional hookups besides what they have at the pump.

*Yep, my lumber yard used a spare 80 gal. tank to do the purging.*

>  I had a good LP service station do it that way once.  Oh well.
>
> And I have gotten away with not purging a couple tanks I replaced valves
> on, but I assume after several empty/fill cycles, they were purged.
>
> Feel free to correct me if I'm wrong.
>
>
>
> --- On Wed, 10/3/12, Dennis Haynes <d23haynes57@HOTMAIL.COM> wrote:
>
> > From: Dennis Haynes <d23haynes57@HOTMAIL.COM>
> > Subject: Re: Propane Tank question
> > To: vanagon@GERRY.VANAGON.COM
> > Date: Wednesday, October 3, 2012, 6:57 PMYou
> > Actually when liquid propane come out
> > of the bleeder the tank is only 80%
> > full with the required vapor space remaining above the
> > liquid. In normal use
> > the tank is always pressurized and even if allowed to go
> > empty very little
> > outside air should be getting in. As compared to a new tank
> > that has never
> > been filed or may even have some water left in it from
> > testing.
> >
> > Dennis
> >
> > -----Original Message-----
> > From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com]
> > On Behalf Of
> > David Vickery
> > Sent: Wednesday, October 03, 2012 4:30 PM
> > To: vanagon@GERRY.VANAGON.COM
> > Subject: Re: Propane Tank question
> >
> > I think people are making too much out of purging a
> > tank.  When it runs out
> > of propane as they often do, it is filled with air.
> > When the bleeder is
> > opened while filling the air is expelled out the
> > bleeder.  When liquid
> > propane starts coming out the bleeder, it is full.
> >
> > --- On Wed, 10/3/12, Mike S <mikes@FLATSURFACE.COM>
> > wrote:
> >
> > > From: Mike S <mikes@FLATSURFACE.COM>
> > > Subject: Re: Propane Tank question
> > > To: vanagon@GERRY.VANAGON.COM
> > > Date: Wednesday, October 3, 2012, 12:15 PM 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.
> > >
> >
>

--
Tom Buese