Mechanics of Carbonation

[Box of Rocks]

Basic question regarding carbonating a keg. Rather than keep my tank on and hooked up to the keg, I’d rather hook it up once or twice a day. Don’t love taking the risk that a small leak can drain my whole tank. What am I missing in terms of the mechanics here? Does constant carbonation pressure result in a better outcome?

 

[J A]

It's a matter of volume. It requires a certain amount of time at a certain pressure to induce absorption of sufficient CO2 into solution. At lower pressure, more time is required. Less time requires higher pressure. Temperature plays a part, too - very cold liquid will hold the gas in solution better and will carb to final volume and stability faster.
The other part of the equation is agitation of the liquid to increase surface interaction with CO2 gas. If you want quick carbonation, put gas on the keg (beer cold) at 40 lbs and shake it for a minute or two. Then top it to at least 30 lbs and let it sit over night. In the morning top it up to 30 again and let it sit until evening. Keep checking and topping to desired pressure after that and you'll probably only have to hit it a few times until it's stable and fully carbed.
Some swear by slow and steady carbing but once it's at desired volume for a day or two after burst carbing, it settles down nicely.

 

[WesBrew]

Basic question regarding carbonating a keg. Rather than keep my tank on and hooked up to the keg, I’d rather hook it up once or twice a day. Don’t love taking the risk that a small leak can drain my whole tank. What am I missing in terms of the mechanics here? Does constant carbonation pressure result in a better outcome?

Sure people do it that way. Crank pressure up to 30, agitate, top it off. Repeat. Using a carbing stone is even faster
I leave my bottle off when kegs are carbed for the same reason

 

[Box of Rocks]

So, as the gas gets absorbed into the liquid, the pressure within the keg decreases. Makes a stronger case for burst carbonation if I’m worried about the leak threat.
Do you also burst carb through the dip tube (assuming no floating dip tube)?

 

[Donoroto]

You can burst carb through the dip tube, but that doesn't buy you much.
Consider applying significant pressure (e.g., 30 PIS) and immediately checking the system for leaks. No leaks, keep the pressure on. leaks? Fix them, as it'll never carb up well.

Leaks can be checked for by spraying a foaming liquid (like StarSan) onto every possible seam and looking for bubbles. A soap solution is also good, but then everything is covered with a little soap, which tastes worse than StarSan.

 

[Minbari]

Basic question regarding carbonating a keg. Rather than keep my tank on and hooked up to the keg, I’d rather hook it up once or twice a day. Don’t love taking the risk that a small leak can drain my whole tank. What am I missing in terms of the mechanics here? Does constant carbonation pressure result in a better outcome?

dont see that working unless you crank it up to like 30-40 PSI. as the co2 is absorbed the pressure will drop and stop going into solution. so you would have to re-pressure it several times a day or it will take forever

if you are worried about leaks. connect an empty keg, pressurize it to 10PSI, leave everything connected and turn the gas off. (ball valve at the reg or manifold) wait a day and verify it doesnt loose pressure.