have i been conned

[txargyll]

hi can you check out these pics, im no rocket scientist but im sure this is wrong so just want confirmation.

heres the script:

Went to local gas depot to see if i could sign up for a BOC account. told i had to wait but that they could give me a bottle of Co2 in the meantime, i was given this bottle for £22.45

Problem was that i had no way of using it as my Argon regulator was too big, so i ordered a new co2 regulator rather than an adapter. That arrived today, 6 days after getting the co2 cylinder.

i attached it and got what i see as a very low reading, for me this bottle should have 250bar of c02 in it but it shows with only 20bar. Presuming i do not have a faulty regulator new out the box, have i been ripped off at the gas depot.

when i got the gas it was not tested infront of me and the staff had no way of testing it themselves, all i seen was the bloke go to what i presume is the full bottle bank and take one from the compond.

20 bar is going to last me what ....... 2 mins! not happy

pics attached

 

[the snooper]

its a pub bottle they only have around a 1000 in them

 

[chevy2]

Argon cylinders are filled at different volumes depending on the supplier,
Boc are around 230 bar, the newer type air products cylinders are higher at around 300 bar but they have their own built-in regulators to handle the higher pressure,
hobby type argon cylinders tend to be a lot lower volumes, can appear to be a better deal until you realise they only have barely half the amount of a boc bottle?

 

[txargyll]

the bottle has 3600 psi stamped on it, i would have though it would be full when you purchase it from the depot, 1000 is going going to last how long on average? is there a calculator i can use or something that will give me at least an idea of how long this gas is going to last? Even if its supposed to be 1000 i clearly have not much less...... think ill take it back tomorrow. hate being ripped off

Really dont see the point in a bottle capable of three times as much gas not being filled, just as well diving is not like that or i would have been dead years ago

 

[pondy]

All the c02 bottles I have had have always been around 20bar. Im sure its liquid inside and fill quantity is measured in weight?

 

[chevy2]

3600psi i'm guessing is max safe working pressure, in reality they wont be filled to anywhere near that,
dont know the exact figures but leave a 2000psi filled bottle out in the sun for a few hours and then test it, it may be 3000psi? thats why when we're at the track we regularly check the tyre pressures right up a couple of minutes before a race and more so on the tyres that the sun is beating on.

take the cylinder back, ideally with your regulator, if they're a decent dealer they should swap it,
check the contents with your regulator before you leave.

 

[mike 109444]

Yep CO2 is fill by weight. Watched the guy fill one in the past. Puts bottle on a set of scales and fills till weight is correct. If I recall the weight is/should be stamped on bottle 9 or 22 kg seam to ring a bell? As Pondy has said the gas under pressure is a liquid and just the space above the liquid is a gas. Which is why you will only see a low pressure on gauge.

 

[Paul.]

All the c02 bottles I have had have always been around 20bar. Im sure its liquid inside and fill quantity is measured in weight?

Exactly this, Co2 is stored as a liquid in the cylinder, the pressure gauge is more sensitive to temperature than anything else, the contents gauge will hardly move during the life of the gas fill then drop like a stone at the end as the liquid runs out.

 

[txargyll]

ok, thanks, ill use it up and see how long it lasts then assess whether to replace or go back to flux core......... thanks guys
(just seems an awful waste of space in that cylinder), currently looking into getting a BOC account for argo sheild light, can i expect the same with a boc cylinder, ie only a small percentage of the bottle filled?

 

[txargyll]

oh one other question, what should i set the other gauge to for .8 mig wire (welding 3mm mild steel),..........going to make my own welding table

 

[Paul.]

Argoshield is completely different, its a compressed gas not liquid, they are currently filled to around 230 bar

 

[mike 109444]

ok, thanks, ill use it up and see how long it lasts then assess whether to replace or go back to flux core......... thanks guys
(just seems an awful waste of space in that cylinder), currently looking into getting a BOC account for argo sheild light, can i expect the same with a boc cylinder, ie only a small percentage of the bottle filled?

Not sure what you mean by waste of space? If you lift the FULL CO2 bottle then compare it to an empty one you will see the difference. Think propane, calor etc are liquid gases in bottle and so done by weight

 

[mike 109444]

oh one other question, what should i set the other gauge to for .8 mig wire (welding 3mm mild steel),..........going to make my own welding table

As it's a pressure gauge being used as a flow gauge then I use to set mine about 1/3 of the way between the 0 and the 50 on yours. So your gauge on Zero is pointing to say 7 o'clock then with trigger pulled set to 8 o'clock, hope that makes sense !

 

[txargyll]

It does, thank you

 

[chevy2]

Exactly this, Co2 is stored as a liquid in the cylinder, the pressure gauge is more sensitive to temperature than anything else, the contents gauge will hardly move during the life of the gas fill then drop like a stone at the end as the liquid runs out.

Never knew that, could be a pain if doing a job over a weekend thinking you enough gas and then suddenly none

 

[BrokenBiker]

Never knew that, could be a pain if doing a job over a weekend thinking you enough gas and then suddenly none

this is why I switched form pub bottle co2 to argoshield (and stick welding) as both times I ran out of co2 it was mid job

 

[Paul.]

Never knew that, could be a pain if doing a job over a weekend thinking you enough gas and then suddenly none

Standing the cylinder on a bathroom scale and watch the weight approaching the tare of the cylinder as you use it is as good an indication as any with CO2

 

[chevy2]

Standing the cylinder on a bathroom scale and watch the weight approaching the tare of the cylinder as you use it is as good an indication as any with CO2

Same principal as the nitrous we use on our cars,
weight is contents and pressure being flow rate,

We generally use whats known as a 10lb bottle, 14lb empty and 24lb full.

 

[dannyp]

pub bottels are tested to a much higher pressure than the are used at with co2 because all the bottels are the same but some get painted diffrently and used with diffrent gas mixes quite a few pub bottels end up being co2 / nitrogen mixes

 

[voipio]

As Chevy2 said, put the bottle, minus regulator, on some scales and weigh it. Anything over the 14.2kg tare weight will be CO2. You could, of course, weigh the regulator and write the new combined tare weight on a label, so you don't have to keep taking the reg off to weigh the gas inside. It's possible to get some idea of how full the bottle is by tapping the cylinder with your knuckles or a lump of wood, but it takes a while to get used to interpreting the sound.

Expect about 40Bar cylinder pressure if the bottle has been left out overnight, about 60Bar at room temp. Cylinder gauges tend not to be very accurate. All of mine seem to read under by 10-30Bar.