Got my new bottle but need help

[Lawnmowerboy]

hi all after finding somewhere that sells CO2 bottles i've got one all in all for £65 from reliable fire protection in leigh on sea,

first class service and a nice shiny bottle but the first bottle he picked up was leaking a tiny bit so he changed it and this seems to be ok
the cylinder weighs 11.15kg as he wrote on the cylinder today as i watched him weigh it

on my brand new wescol regulator with the cylinder head valve fully on the pressure guage reads 500 psi or about 40 bar and im at a bit of a loss as to what its meant to be filled to or is this the norm for CO2 cylinders
ill post some pics if needs be

will

 

[rtbcomp]

That's about right for CO2. It's a liquid so the pressure will remain constant until all the liquid has gone and there is just gas left.

 

[Lawnmowerboy]

okies ta just had me worries a bit i cant wait to get outside now!

 

[shenion]

CO2 should be about 580 to 1000PSI as long as there is any liquid left. It is dependant on temperature.

Mine reads 600PSI right now; right at the lower edge of the green area. I have not had it filled in several years so not sure now much is left.

at 15C it should be about 750PSI.

Maybe your gauge is off. What size bottle did you get?

 

[Lawnmowerboy]

ell the bottle's freezing cold as its been outside most of the day at my dads work
It's a converted CO2 5kg fire extuingusher my regulator goes up to 300 bar and is a genuie brand new off the shelf wescol one
its a brand new bottle all nice with relevant stickers ect...
and an expites in 2020 sticker

 

[stuvy]

just out of interest, why didnt you do the boc offer on the forum, same price for an argon Co2 blend if i read it correctly

 

[Lawnmowerboy]

because i simply wouldnt use it enough to justify the rental and i simply cant aford the albee type ones

 

[pedrobedro]

Co2 cylinders are filled by weight so don't worry about the pressure. If the 11.15 kg is the weight of gas you should be alright for a month or twelve unless you leave the valve open by accident.

 

[voipio]

In a filled CO2 gas cylinder, most of the gas will be in the liquid state. The vapour pressure of liquid CO2, and thus cylinder pressure, is around 60 atmospheres (900psi) at 22 degC, 40 atmospheres (600psi) at 6 degC and 20 atmospheres (300psi) at minus 19 degC. The pressure in the cylinder will remain close to this temp vs pressure curve until all of the liquid has evaporated as the contents of the cylinder are released. Beyond this point, the cylinder pressure will fall as the last of it's contents are exhausted. The way to measure the contents of a CO2 cylinder is to weigh it and subtract from that weight the tare weight stamped on the cylinder. If the cylinder has been stored outside, with the current cold weather, the cylinder pressure will be low. A lot of gauges seem to underestimate cylinder pressure anyway, although 500psi after spending all day outdoors probably isn't far off the mark. If you bring the cylinder indoors and allow it to warm up fully, and the gauge reading increases by little or not at all when the cylinder reached room temperature, it is likely the cylinder is nearly empty.

 

[stuvy]

http://www.mig-welding.co.uk/forum/showthread.php?t=14605&page=23

prices on there, but as you said if you dont do much welding dont worry about it.

Just dont forget to turn it off

 

[Lawnmowerboy]

i wont im pretty hot on things to save money thanks for the clear up voipio
its been near the radiator for about 3 hours and its gawn from 500 to near 800 so its top of the range!!

cheers

 

[Lawnmowerboy]

Hi again, just done the maths the cylinder is marked as weighing 5.6kg so take that off 11.1 so that leaves me with 5.5kg og Co2 does this sound right

 

[shenion]

Sounds about right.

5.5 kg is 2720 liters of gas or about 4.5 hours of torch on time.

 

[Lawnmowerboy]

SCHWEET!!!!! should last me a fair ol'e while then!! thanks guys! is that 4.5 hours at ten litres a minute and can i ask whats the calculation to work out the litres from the weight??

 

[shenion]

CO2 as a gas is 1.977grams/liter.

5.5kg is 5500 grams

5500g/1.977g/l=2782 liters.

2782 liters / 10l/min= 278.2 minutes
278.2 min / 60min/hr = 4.64 hours.

Comes out to #kg * 0.844 = hours or 5.5 * 0.844 = 4.62

Mine is 30lb or 13.6kg for 11.5 hours.

But I mix it 25% with pure argon so that's 46 hours I have gone through 4 argon bottles and never refilled the CO2. I do use argon for TIG.

 

[Lawnmowerboy]

ill take note of that thanks!

 

[Agautosport]

hi all after finding somewhere that sells CO2 bottles i've got one all in all for £65 from reliable fire protection in leigh on sea,

first class service and a nice shiny bottle but the first bottle he picked up was leaking a tiny bit so he changed it and this seems to be ok
the cylinder weighs 11.15kg as he wrote on the cylinder today as i watched him weigh it

on my brand new wescol regulator with the cylinder head valve fully on the pressure guage reads 500 psi or about 40 bar and im at a bit of a loss as to what its meant to be filled to or is this the norm for CO2 cylinders
ill post some pics if needs be

will

Hi ,

What sort of thickness metal are you welding ?
CO2 is usually only good for really thick steel.

 

[Lawnmowerboy]

well anything from bory work/sills to about 5 mill as my welder is only 120a but i know plenty of people that use co2 in a professional capacity
i would have got one of your bottles but couldnt afford it
next time i need a refill i l look at some more options

 

[Agautosport]

well anything from bory work/sills to about 5 mill as my welder is only 120a but i know plenty of people that use co2 in a professional capacity
i would have got one of your bottles but couldnt afford it
next time i need a refill i l look at some more options

Hi ,
just wondered as I was having a conversation with an ex BOC employee recently who now runs his own business and repairs welders . He was confirming all I thought about CO2 but also mentioned a few things that I had not heard before. I understand that CO2 increases the temperature of the arc and therefore make thinner metal welding tricky , also he explained that you get more , or faster, secondary rusting with CO2 , not sure why that would be , maybe the metal around the weld gets thinner due to the increased temperature , or maybe using just CO2 add Carbon the the weld ?? ( Don't know , only guessing )

Any thoughts anybody ?

 

[Lawnmowerboy]

interesting that, thanks