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Re: shop heaters

To: Dave C <cavanadd@kendra.com>
Subject: Re: shop heaters
From: David Scheidt <dmschei@attglobal.net>
Date: Sat, 6 Dec 2003 22:59:59 -0500
>Someone mentioned a "wet leg" connection to their house propane tank 
>for filling up smaller tanks.  Is this something I can have my 
>propane company install?  I thought you needed a pump for that?

Bulk propane tanks have provision to remove the liquid propane, which 
has to be done if the tank is moved.  If you look at your propane 
tank, there are three visible fittings on it (plus the ones under the 
cover).  The first is the ACME threaded fitting that's used to fill 
the tank.   The second is a safety relief valve, which probably has a 
dust cover over it.  There are no threads on this orifice.  At the 
opposite end of the tank is another fitting, smaller and with 
threads.  That's the liquid withdrawal port.  It's got a draw tube 
that goes to the bottom of the tank, a spring loaded valve (like a 
tire valve stem) and some sort of excess flow shut-off.

If you hook the appropriate hardware up to this valve, you can 
withdraw liquid propane.  Basically you need a hose with the right 
fitting to fit the bulk tank on one end, and at the other, the 
fitting to fit your tank (a male POL fitting for most consumer-use 
tanks, various others for ASME tanks, and still others for things 
like forklift tanks) and a ball valve.  If I were filling DOT tanks, 
I'd want a scale and fill chart, as I trust neither the 20% dip tubes 
nor OPDs.

Siphoning and vapor pressure do the work, so there's no need for a 
pump.  It's not really fast.  At best, it's half the speed of a 
filling station with a slow pump.  And if it's way cold, it's really 
slow.  But bulk gas is cheaper than paying at a filling station; and 
it's more convenient.

Your gas company may be happy to provide you with what you need 
(maybe even for "free", since it probably means you'll use more of 
their gas), or they may recoil in horror.  It depends on the laws and 
regulations where you're at, and the gas company.  There's no 
national rule against this, or requirement for licensing for 
noncommercial use.  There may be state or local laws, and of course, 
there are insurance company rules.

David





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