CO2 ripoff

[nilo]

I recently started kegging and my first two purchases of 5lb CO2 refiils were ripoffs as I paid for 5lb and only got 4lb and 3.8lb respectivelly.
I weightned the bottles full and empty on a digital scale that had 1oz accuracy.
I'm wondering if I'm the only one checking this and if this a common issue.

 

[Hammy71]

Aren't most gas bottles filled to 80% anyway? I dunno, thought I read that somewhere.

 

[carlisle_bob]

Hi

The bottle has a "tare weight" listed on the gas bottle. That's what it will weigh when empty. You can request they weight it at the store before you pick it up. You can also bring your scale along. I have a hand held digital luggage scale I use for that and for checking how much is left in kegs.

Bob

 

[audger]

this is an issue to bring up with your gas supplier.

but- how sure are you that your scale is accurate? i would want to be pretty darn sure before i go into a store and complain about something. you could just ask them what is the before and after weight of the tank. if you measure differently, ask them why your numbers are different.

 

[divi2323]

An easy way to check your scales accuracy is to weigh a liter of water. It should weigh a full kilogram.

 

[JuanMoore]

This is very common, especially if you're getting filled at a liquor store or LHBS where they often don't have the equipment to do a proper fill. This is one of the reasons I prefer to do swaps at a welding shop rather than get my tanks filled. I've seen 3.3# fills in a 5# tank at a local liquor store.

 

[carlisle_bob]

Hi

It's a very easy thing to check. If it bothers you enough to do threads about it, check the bottle when you get it.

Bob

 

[nilo]

Thanks Bob, I'll use my scale next time, and no, it is not very easy to check, you need a good accurate scale. Not many of us are willing to invest those $$.
To clarify, I "was" buying my CO2 from a welding supply. My scale "is" accurate and I have double check it few times. TW is not really important if you take a measure of the full and empty bottle.

Thanks.

 

[whitehause]

My local distributor will weigh the tank,fill it, then weigh again and only charge for what they put in. If they are charging a flat fee, then I would question it.

 

[thargrav]

Aren't most gas bottles filled to 80% anyway? I dunno, thought I read that somewhere.

A completely filled CO2 tank is filled to 68% of it's water capacity, in other words, a 5# CO2 tank filled with 5# of CO2 will be 68% full of liquid CO2. But some refillers misread the standard and only fill a 5# CO2 tank to 4#, shorting their customers by 1#.

But this is not likely what is going on with your fills. More than likely the person doing the filling is transferring liquid CO2 from a inverted larger tank or a tank with a dip tube with a simple valve system. While this can be a good way to top off a 5# CO2 tank at home, it's impossible to get a accurate fill this way. So, intentional or not, the person filling this way is shorting his customers.

A fill station and scale are the only way to properly fill a CO2 tank. At risk of being bashed for linking to my web site because some call this marketing, here is Catalina Cylinders CO2 filling document. I would have attached the document but it's too large.
http://www.kegkits.com/CO2/filling.pdf

 

[shelly_belly]

A completely filled CO2 tank is filled to 68% of it's water capacity, in other words, a 5# CO2 tank filled with 5# of CO2 will be 68% full of liquid CO2. But some refillers misread the standard and only fill a 5# CO2 tank to 4#, shorting their customers by 1#.

But this is not likely what is going on with your fills. More than likely the person doing the filling is transferring liquid CO2 from a inverted larger tank or a tank with a dip tube with a simple valve system. While this can be a good way to top off a 5# CO2 tank at home, it's impossible to get a accurate fill this way. So, intentional or not, the person filling this way is shorting his customers.

A fill station and scale are the only way to properly fill a CO2 tank. At risk of being bashed for linking to my web site because some call this marketing, here is Catalina Cylinders CO2 filling document. I would have attached the document but it's too large.
http://www.kegkits.com/CO2/filling.pdf

CO2 tanks are only partially filled to about 34% liquid. The figure of 68% is often quoted as the volume of liquid in a full bottle, but this error probably stems from translating "ounce" into volume using water as the standard. Water is 1.00 gm/cc, or about half the density of liquid CO2 so that if a CO2 bottle is filled to its rated capacity with water, it will be 68% liquid by volume.

 

[thargrav]

Understood, but the real point I was trying to make is CO2 tanks are filled by weight, something none of these home built fill stations can do. More often than not they always under fill then they have no way to adjust to the correct fill weight.

And BTW, small counter top fill stations start at about $3600.

 

[nilo]

Just tried another store of the same welding supply chain and had my scale on hand. Total CO2 was 4lb on a 5lb bottle. The people there stated this is it, you don't get 5lb of CO2, although it is sold as such. They explainned that to fit 5lb would take too much pressure and could damage the valve.

 

[shelly_belly]

That's BS! The weight of gas/liquid that the bottle should hold will be stamped on the bottle. A 5# tank is designed to carry safely a maximum of 5# of liquid C02.

 

[thargrav]

That's BS! The weight of gas/liquid that the bottle should hold will be stamped on the bottle. A 5# tank is designed to carry safely a maximum of 5# of liquid C02.

I agree - a 5# CO2 tank has been sized to safely hold 5 pounds of CO2. This reseller is using the liquid transfer method to fill tanks and this is his excuse for not filling your tank or he does not understand the system. Either way you need to be shopping with someone else.

 

[P-J]

This is a very interesting thread as I refill my own 12 & 20oz PaintBall tanks from a 20lb tank. I fill to the exact tare weight of 12 or 20oz.

The way I do this is to put about a 1/2 ounce of liquid CO² in the tank and then dump it. The sudden interchange freezes the tank and that allows me to fill it to its proper weight as the receiving tank is now freezing cold. I do the same thing with a 2.5 pound tank that I use in my kegerator.

What I'm reading on this thread is the people filling the tanks don't have a clue. They are filling to the point that each container's pressure equalizes. They are really charging you for their lack of knowledge. (Or - they know they can get away with it.)

BTW: I refill my 20 pounder at a local shop that does refills and also recertifies the tanks. They refill using a CO² liquid pump and they fill to the exact tare weight.

Just my experiences...

 

[thargrav]

You are 100% correct, and here are Catalina Cylinders filling instructions.

http://www.kegkits.com/CO2/filling.pdf

I would just upload the document but it's too large.
And the target weight referenced in the document is the weight marked on the tank - for a 5# tank, the fill would be 5 pounds.