20lb Propane tanks - Can you fill from your home tank?

[hawkeye08]

There is a lot of mis-information in this thread. I had my propane supplier add a wet line to my 500 gallon house tank. Put on a pair of gloves, attach the hose to your grill tank, open the valve. What is interesting about LP is that no matter how full the tank is, the pressure is nearly the same. You crack the bleeder on the small tank and the liquid fills it from the pressure differential. There doesn't have to be much difference in pressure to get the gas to flow. Gravity has nothing to do with it. The new tanks do have a float the shuts off the flow when they get full, but I don't really trust them. You fill until liquid comes out the bleeder. Don't smoke when you fill your tanks. Yes, propane is heavier than air. Gasoline liquid and vapor is also heavier than air. Gasoline is probably just as dangerous as LP, but everyone is used to gas. If you don't already have a liquid valve on your tank, you may have drain your tank to add one. The hose setup cost me about $120 installed. I have easily saved that by refilling my tanks. Because of the difference in safety valves on the tanks, some are quicker to fill than others. I have some that will fill in less than 5 minutes, others that take 15 minutes or more to fill.

Can you post a picture of this wet line you mention? I doubt our tank has one and we never let it get empty so it would be expensive to add I would expect.

 

[charlz]

A wet line at home would be nice to fill my smaller tanks and the RV.

As a side note I just happened to perusing some local electric company info today regarding meter installations etc. They stated the meter has to be no less than 10 feet from a propane relief valve, etc that might release gas. It has to be 20 feet from a tank used for refilling other tanks. I would have to measure but I think mine might be a hair closer than 20 feet from my meter. I wonder if the propane company follows the same regs if they came out to put in a wet line?

 

[s2man]

We filled forklift tanks from a large tank at work. No pump, just pressure differential. When it was cold and the big tank was low it took quite a bit longer to fill than on a hot day with a full tank, as Boyle's law states.

I was wondering about the gas laws through this whole thread. With identical temperatures, wouldn't the 500g tank and the 20lb tank even out at the same level? ie, 80% full pig would fill small tank to 80%, 50%->50%?

Its been decades since I took college chemistry...

 

[flyerdan]

It probably would if the smaller tank wasn't vented to atmosphere to allow filling it. The filling tank will always have a greater degree of pressure.

 

[CalG]

It does not take much temperature difference to make a significant pressure differential that does the filling.

https://www.propanecarbs.com/images/propan4.jpg

The paintball crowd terms propane "green Gas". They refill from larger tanks all the time.

If you are afraid of the stuff, well so be it.

 

[Industrial Toys]

I bought a fitting to fill torch tanks from a BBQ tank in the STATES. Prime Minister DAD, won't let us play with such things here. I followed the instructions and kept the cylinder in the freezer, but never get much of a filling. Not much at all, and that is from a brand new BBQ tank.

 

[buickanddeere]

I saw in the Harbor Freight flyer an attachment to the 20lb tanks - it says "Propane Bottle Refill kit' Item 45989. It got me to thinking about this again - I've thought it several times . There should be some way us normal folk can fill our smaller tanks from our bigger home tank. It's much cheaper for us to buy bulk LP than paying a premium at the store - plus having to drive there to do it.

If this is possible, what is the procedure and parts needed?

And, more importantly, is it safe?

How much do you plan on saving by home filling the 20lb tanks from the bulk tank ?

 

[dpb800]

I just plumbed our grill directly into the propane tank for the house. Don't need 20lb tanks anymore.

 

[Deere Dude]

How much do you plan on saving by home filling the 20lb tanks from the bulk tank ?

For me it wouldn't be so much a money saver but a challenge. Just to be able to do it would be enough justification.

 

[nap61]

When we built our house, I had the plumber run a line with a shut off valve near my back patio. I added a quick connect fitting and a 10 ' hose which I connected to my grill. The hose and fittings cost about $80 at a local Ace Hardware.
I have several 5 and 7.5 gal. tanks for my crawfish burners and jambalya pot. I have to see if I can get a wet line added to my house tank.
Thanks to all for the info.

Norm