How low of psi until I should refill

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MrWhleDr

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I have a #20 tank that is at about 750psi. I am wondering when I should exchange the tank so that I dont run out one night with no access to another. I know a second tank would be ideal I force carb and serve at 12 psi. Have carbed and served 60 gallons with this tank. I have only forced at 30psi with 2 or 3 kegs. When does everyone decide its time to exchange/refill so that you know you can continue serving? Thanks
 
The high pressure gauge on a CO2 regulator is pretty much useless.

It will show a constant pressure until the tank is literally almost empty, and then it will drop really fast. This is because CO2 is stored in liquid form in the tank. As long as there is any liquid in there, it will be the same pressure. Only when the liquid is all gone and you are down to the last bit of CO2 will the gauge start to change.

I just fill when it empties. IN fact, I dropped my tank a year or two ago and busted the hell out of the high pressure gauge, so I don't even have one on my regulator anymore.

:D
 
Keep a spare or assume that when the pressure gauge drops you have minutes to hours or a day depending on usage. More than likely it will run out Saturday night so you have to wait until Monday for new gas. I bought two extra 5#'s on Craigslist for very little $$$ and it including regulators.

btw - weigh the tank and subtract the tare number from the tank.
 
btw - weigh the tank and subtract the tare number from the tank.

I've always wondered.... does that tare weight include the valve? I know it does not include the regulator, but was unsure about the valve.

My guess is that it DOES include the valve, because it would be pretty hard to make use of the tare weight if you had to unscrew the valve on top. :D
 
On my 20# tank when the pressure starts to drop I have a little less than 2# left. (10% of a new fill) I use about 2.5# a month. That means when the pressure drops I have about 3 weeks to go. I weigh my tank when new and subtract the tare weight, so far the tare weight included the valve. If I weigh the full tank and valve with a tare of 28# it will show 48# when full. I then add my regulator and use a hanging grain scale to get the new weight. I write it on paper and tape it to the cylinder with the date. Any time I question how much I have left I simply hang the tank and regulator on the scale. I use the same grain scale to track propane use and to weigh bulk grains.
 
The high pressure gauge on a CO2 regulator is pretty much useless.

It will show a constant pressure until the tank is literally almost empty, and then it will drop really fast. This is because CO2 is stored in liquid form in the tank. As long as there is any liquid in there, it will be the same pressure. Only when the liquid is all gone and you are down to the last bit of CO2 will the gauge start to change.

I just fill when it empties. IN fact, I dropped my tank a year or two ago and busted the hell out of the high pressure gauge, so I don't even have one on my regulator anymore.

:D

I did the exact same thing not long ago. As long as there are no leaks, I don't really care about the high-pressure gauge; it was never accurate anyway.

I just keep a second tank around for swaps and never run out. Like propane tanks.

Those tanks are pricey, no? I use this and this. I have them around anyway for camping trips and such, so when my CO2 tank dies, I use that to dispense until I have time to get the tank refilled. Just another option if the OP is interested.......
 
Although the high pressure gauge can't tell you much, it can tell you when you are nearly out. When the pressure hits 300 psi (whether you keep it in the kegger or outside) there is no more liquid CO2 in the tank. At that point, you can still serve a keg, but you wouldn't be able to force carbonate. (well, maybe with a 20# tank).
 
I have heard that you are not supposed to let a tank go completely empty either as that could allow some moisture to enter the tank and possibly rust the inside causing nasties in your beer. Take it for what it is worth but I always try to fill mine before it hits zero.
 
I weighed my 20# tank once when the high pressure started dropping. It was around .6 oz over the tare weight. I was able to push 2 more carbonated kegs worth of beer. So for a large CO2 bottle, the high pressure gauge is useful.
 
rjsnau said:
I have heard that you are not supposed to let a tank go completely empty either as that could allow some moisture to enter the tank and possibly rust the inside causing nasties in your beer. Take it for what it is worth but I always try to fill mine before it hits zero.

Most folks have a check valve on the regulator that prevents anything from going to into the tanks.
 
Dude, you either drink an ungodly amount of beer or you have a leak somewhere. Unless you use your CO2 to rack beer, I can't see how you could use that much.

LOL probably a little of both. I use CO2 for everything. When I clean kegs I rinse, fill with CO2 to clean the out tube, and the beer lines, depressurize, fill with oxyclean, pressurize out through the out tube and through the beer lines, depressurize, fill with Iodopher and repeat the process, depressure and fill empty keg with gas and run that through the lines and store under pressure. When filling bottles from a keg I degass and drop pressure, after bottling I raise the pressure to serve. I blow out all my lines from keg transfer and bottle fill. If I secondary I gas the secondary before transfer. I have no idea how much I would use if I only carbonated and served.
 
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