Co2 Canister Position

[Dave Spencer]

I meant that the OP's question about laying a tank on its side need not go there.

Here`s you reading my links, when I couldn`t even read the OP properly.

My humble apologies.

One thing to consider when first bringing a cylinder in to the home is that temperature of the cylinder and, therefore, the gas pressure, will rise. This will mean that the regulated pressure could end up a little higher than thought.

I have had an incident where I connected a new cylinder that read 100Bar (twice what I expected). Cursing the broken regulator, I connected another, which also read 100Bar. During this time, the pressure in the cylinder rose to a point where the cylinder relief valve blew. I had to change my underwear pretty sharpish. Being a relief valve, the pressure was relieved under control, but was very noisy and made the room instantly foggy. Generally, this isn`t a problem, as I have found that I don`t need to touch the regulator from one cylinder to the next.

Imagine if the relief valve had blown whilst I was driving the cylinder home. Get the vendor to visually confirm the pressure for you, before taking it away with you.

Pressurised CO2 cylinders are inherently safe, but need to be treated with the utmost respect.

Dave.

 

[waterdrop]

wow, nice comments Dave.. also very good for those of us still learning about the world of CO2 cylinders!

In the story you related, was the problem that the vendor filled the tank to a higher pressure than you wanted or something or was it the issue of raising the tank temperature too fast by bringing it in from the cold? And how would one be supposed to go about a slow temp raising if that's an issue to learn with these tanks?

~~waterdrop~~

 

[kcharley]

Interesting reading. When I had my cylinder filled (its my first), I asked to what pressure they filled it. Their response was they fill by weight, not by pressure and stated that at 70 degrees the pressure would be 800 lbs. Of course I wasn't quick thinking enough to ask what temp they filled it at, but the tank itself was very cold. (I had it filled at a fire extinguisher shop so I'm assuming they know what they are doing.) For comparison, my air compressor tank fills to 140 lbs and I believe that tank is rated to 200 lbs. I'm careful and easy on things by nature but 800 lbs of pressure makes me real careful. Like OM47, I wasn't about to let that tank roll around on the way home.

Greg

 

[fatheadminnow]

Interesting reading. When I had my cylinder filled (its my first), I asked to what pressure they filled it. Their response was they fill by weight, not by pressure and stated that at 70 degrees the pressure would be 800 lbs. Of course I wasn't quick thinking enough to ask what temp they filled it at, but the tank itself was very cold. (I had it filled at a fire extinguisher shop so I'm assuming they know what they are doing.) For comparison, my air compressor tank fills to 140 lbs and I believe that tank is rated to 200 lbs. I'm careful and easy on things by nature but 800 lbs of pressure makes me real careful. Like OM47, I wasn't about to let that tank roll around on the way home.

Greg

Yeah, when I play paintball, the Co2 tank on my paintball gun is at 800 lbs, and that thing gets bashed around, dropped on the ground and what not all the time while I am playing, but I am not saying you should do that with your Co2 tank...lol. And I also use compressed air tanks on my Co2 tank, and when that is filled that is in the range of about 4000-5000 lbs!

So I guess 800 lbs is not that much, ... but that does not mean you should not be careful with it.

-FHM

 

[OldMan47]

A CO2 tank is filled by weight because the CO2 inside is in a liquid state. As soon as there is any liquid at all in the tank, it will be at a pressure that corresponds with its temperature. As it fills more, the pressure won't change unless the temperature changes. The weight will go up as the liquid fills the available space. If you get a fill from someone who is not quite doing things right, the tank could be filled solid with liquid. At that point, any slight warming would try to boil the liquid but there would be no place for it to go. The result would be a large change in pressure similar to what Dave described. That is why there is a relief on the tank. If there is room for the liquid to boil before the tank gets full of liquid by its expansion, the tank will stop increasing pressure when a new equilibrium is reached. For a safety margin, there should be at least 10% or more of free space above the liquid level in a full CO2 tank to allow expansion and minor temperature swings without large bottle pressure changes.

 

[kcharley]

OM47, I'm going to have to take a closer look at my valve tonight for this relief valve. I'm familar with a relief valve on a hot water heater but I don't remember a relief valve on the CO2 tank, just a regular valve. Is the relief valve integral to the regular valve? If so, where will it vent to once the regulator is attached? Maybe academic until the gas is used up, I could install one then.

The extinguisher company that filled it were happy to see a new tank with a certification. Hmmm, ignorance may be bliss but I may have missed something important.

FHM, 4000 - 5000 lbs of compressed air. Wow! What is the range with that pressure? That's got to sting whoever gets hit. Think I will stick with fish, and my motorcycle. Now that's safe.

Greg

 

[waterdrop]

There's a nice clear pic of a pressure-relief valve on a dual-gauge regulator in this PDF file from a beer-making outfit:

PDF with CO2 Regulator Picture

(Its the first color picture down, next to the "Connecting Regulator to CO2 Tank:" section.)

~~waterdrop~~

 

[kcharley]

There's a nice clear pic of a pressure-relief valve on a dual-gauge regulator in this PDF file from a beer-making outfit:

PDF with CO2 Regulator Picture

(Its the first color picture down, next to the "Connecting Regulator to CO2 Tank:" section.)

~~waterdrop~~

Thanks WD,

That picutre certainly helps. I think I have a problem. I don't remember a pressure relief valve on my regulator. A little embarassing to admit but I didn't even think of it. It shouldn't be too hard to add since it is actually after the main valve. I'll check when I get home and I bet go on-line shopping tonight.

Greg

 

[Dave Spencer]

There should be a relief valve on the cylinder.

 

[waterdrop]

There should be a relief valve on the cylinder.

Pics! we want pics!

(Is it on the hardware that screws to the neck or somewhere on the cylinder itself or are there different types?)

wd

 

[Schmill]

I've heard of the release valves releasing when in cars etc on the way back from a refill, so I would guess it is built into the cylinder itself rather than part of something you attach to it. After all the valve is there to prevent the cylinder rupturing, so it wouldn't make sense for it to be on a remote piece of hardware. I think it MUST be built into the cyclinder somewhere...

 

[kcharley]

I think Dave is right. I was so engrossed in getting it setup that while I wondered what it was I basically overlooked it. I'll try to get a pic up later tonight. I'll try to describe it. The fitting for the regulator is obvious. On the opposite side of the valve there is another fitting that appears to be plugged but it is an odd plug in that it sticks out about 1/2 inch. The plug has a small, I'm guessing 3/16 inch hole and looks like it could almost be pushed in with your thumb. I'm guessing that is the relief valve. I'll try to research it a little later. Thanks for the help.

Greg

 

[waterdrop]

that would be gr8 greg

 

[OldMan47]

That sounds like a tank relief KCharley.

 

[kcharley]

I hope you can see the pic. (I am such a dinosaur. )

What I believe to be the pressure relief valve is on the right side, the piece with the hole in it. I found a similar design on the internet yesterday, so I am pretty sure this is it.

In case the link above works, following are pics of the tank and the tank and stand.