Why the tank pressure guage recommendation?

[Jonnio]

Ok, as I go through the exercise of building or buying another kegerator (for my dad this time) I was wondering why I see two things pretty much as an unwritten rule in threads regarding kegging.

1) get a "better" regulator that that has a high pressure guage
2) the high pressure gauge will read high pressure right up until the tank runs dry making it an unreliable way to tell how much CO2 is left in your system.

So, what am I missing? I find myself never looking at the high pressure gauge, so what is the reason to spend the $30 on one?

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EDIT based on thread discussion
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OK - the big thing I had wrong was that the gauge is only about $5, so it really isn't a big deal if you have the choice.

The amount of warning that you get from the gauge is dependent on the temp you keep the bottle at and the size of the bottle so those of us with 5lb bottles in the fridge get a pretty minimal amount of warning.

 

[ShortSnoutBrewing]

I think it boils down to personal preference. I don't buy into the whole

2) the high pressure gauge will read high pressure right up until the tank runs dry making it an unreliable way to tell how much CO2 is left in your system.

speech. Mine totally tells me when it's getting low and when it's totally empty. I'm never caught off guard by suddenly not having any gas, unless I'm simply not paying attention.

 

[Jonnio]

I think it boils down to personal preference. I don't buy into the whole speech. Mine totally tells me when it's getting low and when it's totally empty. I'm never caught off guard by suddenly not having any gas, unless I'm simply not paying attention.

Do you keep yours inside or outside the fridge?

 

[david_42]

Once a high pressure gauge hits 250 psi, you're running on fumes regardless of the temperature. So, think of them as a late warning system, much like the idiot light on a gas tank. Doesn't mean you are out, but you best start thinking about getting more.

 

[Jonnio]

I will start watching mine closer and see how it goes....I had the bright idea last time I picked up my tank and it was about out (could maybe have pushed another 1/2 to 1 keg) that I would go ahead and get it filled, thinking it would be like propane where you pay for what they put in....well, the first thing the tech did was open the valve and empty the tank DOH!

 

[Beerrific]

I think it boils down to personal preference. I don't buy into the whole speech. Mine totally tells me when it's getting low and when it's totally empty. I'm never caught off guard by suddenly not having any gas, unless I'm simply not paying attention.

I agree. At the rate the I use CO2, there is a good month or two from when I start to see the pressure drop and when it hits zero.

 

[LooyvilleLarry]

Ok, so what pressure is yours at when it is "full"?

 

[Jonnio]

I have pushed one keg and force carbed none and mine is at about 500.

 

[Beerrific]

I have pushed one keg and force carbed none and mine is at about 500.

In the fridge? Or room temp? Mine is at about 850psi at room temp.

 

[Jonnio]

In the fridge? Or room temp? Mine is at about 850psi at room temp.

Mine sits in the fridge

 

[donaldson]

2) the high pressure gauge will read high pressure right up until the tank runs dry making it an unreliable way to tell how much CO2 is left in your system.

I have found the high pressure guage a completely reliable way of telling how much CO2 is left. With my 10lb tank, it can take a couple of weeks for it to slide from 750 or so down to 100 or so. And that's two weeks of fairly good use out of that tank yet.

But I do know that the day the pressure starts to drop means that it is time to refill the tank, even if I have a week or two before it becomes critical.

 

[kirscp]

Just depends on if you want to take chances.

A high pressure gauge will let you know if you have a leak in your system .. a noticeable drop in pressure in one day will let you know to tighten up fittings. Better finding out by an empty tank.

Also, if you are running low, you'll have heads up on getting it filled. If you are coming up on a 4 day weekend with a get together planned, sure hate to run out on Friday evening, with no place to fill.

Its just like a fuel gauge on your car, not a necessity, but sure helpful.

 

[Jonnio]

Here is some info on pressure vs. temp of CO2
http://www.warpig.com/paintball/technical/gasses/co2pv.gif

I am going to sit down and see if I can do the math on how much CO2 is left when I hit 250 psi at 43 F

 

[Jonnio]

Ok, someone can double check me here, but I think it kind of makes sense

On a 5 lb keg in the fridge at about 40F by the time the pressure gauge moves you have used 85% of the CO2 in the bottle. Figuring 10 kegs per bottle you should still be able to push another keg or keg and a half.

If you keep your CO2 outside of the fridge you will start getting pressure changes at about 30% full. So about 3 kegs worth. So you get more leeway.

At 250psi both temps are about 5% capacity, so less than a keg from empty.

I think that is probably where the problems come in for those of us that keep the CO2 in the fridge. If your having a party on Saturday and your gauge is still reading full pressure on Friday there is a chance that 2 kegs or less later you could be out. Depending on the size of the party that may be an issue.

I guess for my dad I might recommend putting another $25 with the $25 cost of the high pressure gauge and just buy a second bottle, then you have a full and an empty. Should never have an issue unless he gets really lazy and lets them both run dry.

 

[conpewter]

I strongly suggest watching craigslist or whatever and picking up a 2nd tank when you can. It is really nice to just switch out the tank if you need to, and fill the other up at your convenience. I got a 20# tank off craigslist for $15

 

[kirscp]

So, what am I missing? I find myself never looking at the high pressure gauge, so what is the reason to spend the $30 on one?

A high pressure gauge costs around $7.00 and upgrading from a single gauge to a dual gauge regulator is around $5.00. For $5.00, its worth it.

 

[Jonnio]

A high pressure gauge costs around $7.00 and upgrading from a single gauge to a dual gauge regulator is around $5.00. For $5.00, its worth it.

Yeah, I went back and looked. I am not sure where I found the $25 price. It is pretty cheap.

 

[beerfactory]

I just weigh my tank if I'm curious to know what I've got left. Pretty simple. But, I had a single gauge regulator given to me...so I didn't have a choice to make.

 

[Hodawg]

Currently I keep a second tank on hand and use it strictly for charging/conditioning. That keeps me from having to dink around with my primary tank-regulator setup when I charge a new keg. I can also leave my regulators set at a constant psi. In the event that my primary tank of CO2 runs dry, I simply swap tanks. The extra tank and regulator set up is well worth the money.
Beers,
Ken

 

[MoRoToRiUm]

+1 on multiple tanks- as Jonnio posted, there is a difference in PSI depending on temp. CO2 is a liquid gas so temp plays a factor. You have more of a heads up with the tank external then in the fridge, but a warning both ways. It's just a matter of once it starts dropping below a certain point, it goes fast due to the nature of liquid gas.

 

[Jonnio]

+1 on multiple tanks- as Jonnio posted, there is a difference in PSI depending on temp. CO2 is a liquid gas so temp plays a factor. You have more of a heads up with the tank external then in the fridge, but a warning both ways. It's just a matter of once it starts dropping below a certain point, it goes fast due to the nature of liquid gas.

Right, basically the high pressure gauge isn't going to move until you are out of liquid CO2. The higher the temp the more CO2 will still be in the bottle when the liquid is all gone, so you have a bigger notice.

 

[Bobby_M]

The pressure only starts to drop once you have ZERO liquid CO2 left to boil off. At that point, the literal volume of the tank comes into play. If you have a 20lb tank which is approximately the same size as a corny, and it's down to a couple hundred psi, you'd have enough to dispense a few kegs. However, you used about 3x the gas to force carb than it takes to dispense. How critical it gets depends on your accessibility to quick fills or exchanges. I don't want to be forced to drive out somewhere so I did get an extra tank.

 

[StunnedMonkey]

Currently I keep a second tank on hand and use it strictly for charging/conditioning. That keeps me from having to dink around with my primary tank-regulator setup when I charge a new keg. I can also leave my regulators set at a constant psi. In the event that my primary tank of CO2 runs dry, I simply swap tanks. The extra tank and regulator set up is well worth the money.

+1

This is what I do as well. Second tank and regulator for maintenance purposes and for pre-carbing kegs before they hit the kegerator. I even add a third CO2 bottle on standby...just in case. I can't deal with a lack of CO2.

I can't. I won't.