Refill Propane canister

[Patrick]

I have been refilling my small propane canister from my bulk tank. Via the propane adaptor. What I noticed is it always fills only about 3/4 full.
after I remove the canister from the frig. (cold) I leave it inverted attached to the bulk tank for one minute. But it only fills about 3/4 full. I know some of you use this method. Am I doing something wrong, or is this as good as it gets?

Patrick

[SomeSailor]

First things first... make sure you're not overfilling them. I weigh them empty and then fill them for an even pound. Invert the large bottle while filling and listen for the bubbles as the liquid trickles in.

You can release a little of the head pressure by pulling out on the valve stem (yes... thats a pressure release that opens outward).

You can fill them to over a pound, but you run the risk of one bursting or leaking. I did have one bulge slightly after "guestimating" the weight. I always weight them on a postal scale now. been filling them for a couple of years now and they work great (never bothered cooling them). Just be safe.

[Patrick]

I didn't think I was over filling the canister. It appears to be under filled. A store bought one has very little space inside the canister. The ones I fill from the bulk tank ,slosh around like it 's only partial full.

The directions that came with the adaptor says to put the canister in the frig for 20 min. before filling.

[SomeSailor]

You have the main tank inverted? Try pulling the stem a little bit on the 1 pound can a little bit to relieve the gas pressure. A pair of needlenose pliers or hemostats works great. Just be careful to watch for overfilling. I use a digital postal scale to get them to a pound each.

I can fill a dozen in just a few minutes. It sounds cheezy, But considering propane can be had for $1.50 or so a gallon, you're getting refills for around 35¢ each (4.24lb / gallon).

[tolly28]

You're most likely not overfilling the cylinder, rather you are simply equalizing the pressure between the two cylinders, and you're really not transferring much LPG at all. As mentioned, you can invert the larger tank, but keep in mind your OPD might prevent it from working.

Disposable cylinders aren't really meant to be refilled, and they're not that expensive. I choose to toss 'em.

[SomeSailor]

Actually the OPD (overfill protection device) if just a float. And, without the tank completely inverted, it may keep the valve partially closed.

It's like any liquid... if you invert the tank, the propane will gurgle down into the smaller tank even with the pressures equal (just takes a awhile). Relieving the pressure a bit allows the liquid to transfer faster.

Propane vapor pressure is on the order of 90-125 psi. Refilling a propane cylinder is no more dangerous than fueling a mower or inflating a tire. Your average can of hairspray is probably more dangerous.

[tolly28]

I guess I just look at it from a risk/benfit/hassle standpoint. I've never really thought the whole process was worth the time and hassle for the buck I might save.

I maintain that disposable cylinders are not intended to be refilled. They rust from the inside out and their valve assemblies are not built for repeated use. I've never feared a can of hairspray would blow up my boat.

[SomeSailor]

Your call.

[Tedster]

I'm with ya Steve!!! :D

[SomeSailor]

They're steel containers. If they're rusted they get thown out. If a person can fill them for 35¢ instead $2.99, I see no harm.

I would rather save a few bucks and avoid throwing all that steel in a landfill somewhere...

[3788sam]

I gave up on those one pound bottles and bought a 5-pound regular bottle and a hose to hook up to the grill and Lantern.
Doesn't take up much room and it makes it thought the season up on Lake Chelan!

[Tedster]

....and a whole lot safer to fill I'd say! :D

[SomeSailor]

Not any safer at all. A steel bottle will not fail for no aparent reason. These are low pressure bottles (propane) so they don't require hydrostatic testing (even the refillable ones).

It's simply a matter of convenience. They get you to pay for the bottle and the gas it carries. Do you think there is some magical process for filling a container with liquified gas?

Filling a car tire is more dangerous.

[Tedster]

The big difference is that someone else is doing it for me....duh! :shock:

[SomeSailor]

I suppose you get Debbie to fill the mower for ya too? :D

[Tedster]

Nope, Josie handles that one for me! :lol:

[3788sam]

Off Topic!
Ted - Are we going to see you Thursday night at OBC?
Would be nice to finally shake your hand and say hello in person.

[Patrick]

Yes, I invert the canister each time I fill it. I'll try to bleed some out next time I fill one and see if I get it to 1 Lb.

Thanks

Patrick

[SomeSailor]

Yeah... you can actually get them up to like 1.25#, but It's really easy to weigh them and keep them at around 1 pound. Been doing it for a couple of years now and never had a problem. I also fill liquid CO2 here for my son's paintball gun. Now THAT is something you have to pay attention to! :)

It does help to freeze those (or just vent a bit of liquid real quick and the cannister freezes itself instantly). With CO2 you need a special syphon tank. Mine is an 180 cu ft tank.

[3788sam]

You can really save big refilling those 1lb bottles.
2 to 3 bucks for those bottles add up fast, and god forbid if you need to buy one on Lake Chelan $$$$

[tolly28]

Actually, LPG cylinders used in a non-commercial setting do require hydrostatic testing.

Seems like most people replace them instead.

[Tedster]

Off topic......yes Ken I will be there! :D