Refilling a siphon co2 tank with a larger siphon co2 tank

thedrunkdutchman · Jun 21, 2019

So I know that you need a siphon co2 tank to fill non-siphon tank at home, but would it be just as easy to fill a siphon tank? The reason I ask is that in my area, it would be cheaper to get a 50 lb tank take it home over the weekend and fill up a couple 20 lb siphon tanks and some smaller non-siphon tanks, then take it back on Monday. That way I can at a later time refill my smaller tanks for keging but not have to pay rent everyday on the large tank.

day_trippr · Jun 21, 2019

Sure it'd work, how do you think the 50 pound siphon tank was filled?

The fly in the ointment is filling loss - you can lose a good fifth of your liquid CO2 filling smaller vessels because you need to blow off pressure build-up to keep the liquid CO2 flowing. So you'd need to figure the loss into the math to know it's a win in the end...

Cheers!

thedrunkdutchman · Jun 21, 2019

Thanks @day_trippr, I figured that it would be the same but I wanted to confirm it and none of my Google searches gave me a definitive answer. And I also should have added to my original post that the other reason for wanting a siphon tank around the house is so I can fill paintball tanks and sodastream tanks for portable draft beer systems.

gnef · Jun 22, 2019

How much would it cost for you to buy the 50# tank outright? Looking at all the smaller tanks that you are filling, it may make sense for you to own your own 50# siphon tank, and that way you don't worry about the double filling loss from the 50# to the 20# to your smaller tanks, and if you own your own tank, then you don't have to worry about any rental costs or if you are using it quickly enough to make it worthwhile.

I personally have two 50# non-siphon tanks for my everyday use, and five 20# tanks for portable use and backup. It is nice having the 50# tanks since they last so long, it is just a pain when they do need to be refilled since mine are steel and are quite hefty!