SAFE - Tested Co2 Cylinders from Doncaster  01302 366332


Rent Free Co2 Cylinders for Yorkshire

Co2 cylinder questions & answers

Q When I have my bottle filled at ****** it doesn't last as long as when you fill it, is there a reason for this?

A Here at Doncaster we invested in a special liquid Co2 pump so we could pump the liquid Co2 from our 45kg cylinders into the smaller receiving cylinder this allows us to put the full amount (3.00kg 6.00kg 15.00kg or 22.50kg) by weight into the cylinder.

Companies who 'pressure fill' have great difficulty in putting more than 30% to 60% of the correct weight into the cylinder, this means you only receive 3.00 to 4.50kg in a 6.00 bottle but still get charged £20 for 6.00kg Co2.


My maximum height in my cabinet is 530 mm. Will the regulator fit within that height. How long will 3kg Co2 gas last?

A The highest point on the bottle is the handle (currently 510 from ground) the side outlet for regulator is approx. 80mm below the top of handle, plenty of room for regulator.

We advise you to weigh the bottle when you get it home. Write the weight down somewhere safe put the date on, after about 28 day reweigh the bottle this will show you how much liquid Co2 you have used, divide this amount by the number of days used then divide the amount per day into 3kg giving you the total number of days usage for a full 3kg cylinder.

eg. initial weight 4.87kg  30 days later 3.30kg.

4.87kg - 3.3kg = 1.57kg liquid Co2 used

1.57kg /30 days =  0.04566 per day

3kg (weight of liquid Co2) divided by 0.04566 (amount per day) = approx 65 days


Q I have BOC cylinder Can you fill it for me?

A BOC only rent bottles. The bottle you have has been stolen, you are handling stolen property. You need to take your bottle to the nearest BOC warehouse and pay the £60 per year outstanding rent that is due, sign a new contract and obtain your gasses from BOC Alternatively you can come on over to Doncaster and purchase a legal 'RENT FREE' bottle for £45 + £20 for Co2 total £65 and pay NO rental fees

Q How many litres of co2 gas are in your 3kg bottles

A 1 kg of liquid Co2 expands to about 550 litres of Co2 gas at atmospheric pressure

The Co2 in the cylinder is in the liquid state i.e. “under pressure liquefied”. The pressure in the cylinder is approx, 830psi  57bar at 20c .When Co2 is withdrawn from the cylinder through a regulator at an outlet pressure of less than 75.5psi  5.2bar gaseous Co2 is produced.

Therefore 3 kg of liquid Co2  X 550 litres = 1650 litres at atmospheric pressure.

Q What are the thread sizes of your Co2 cylinders?

A Throughout the world, carbon dioxide cylinder valves have a special thread. In Europe, Africa and much of Australasia, the thread conforms to British Standard 341 Part 1 (.860 in x 1/14 in W) or the direct European equivalent (DIN 477, SN 219505, etc). These threads are in effect interchangeable.

 British BS341 No.8 European DIN 477 No.6 and SN 219505Type 7     

 French NF E 29-650 Type C  Australian AS2473 Type 30

America CGA 320 and Japanese JIS B 8246 CO2 threads are different and are not compatible with each other nor with British/European CO2 threads).


Q I'm setting up 2 large reef tanks can you supply me with Co2 for Reef tanks i will require 3 pub size Co2 bottles? and is it 'food grade' Co2

A All the Co2 in our cylinders is 'food grade'. Aquarium Co2 should only be food grade 

Yes we have 3 full ones in stock you pick up from the house so just give me a bell when you want to collect and I'll make sure I am here. 

I bought a Co2 cylinder off you 3 months ago for welding my gauge is showing empty and I don’t seemed to have used it much, could it be leaking?

A Most gauges on regulators only start showing any pressure above 1000psi. Co2 bas has a pressure of 840psi above that pressure the Co2 condenses to a liquid, This customer came in with his friend 3 or 4 months later and said he was still using the bottle.


hi there do you fill all bottles or only ones supplied by you as i have different   bottles and i,m a problem to get filled they are all in good date thanks jim

A We can fill most bottles, please give me a bell to confirm yours is ok.

 Q is it legal for me 2 have one of these in my car whilst traveling?

There shouldn’t be a problem. But please be aware that in the case of an accident the emergency service will need to quickly identify them in case they contain combustible or explosive gasses. If you are carrying cylinders regularly you should have the appropriate warning label affixed to the back of your car and on the entrance to your workshop. 

Must be secured and properly labeled, children not allowed as passengers. Its all just common sense really, the main thing is to secure it, it’s a small but very heavy lump of liquid gas and must be treated as highly dangerous. Please phone for availability first.


 Q   Where can you deliver to in Yorkshire ?

A Sorry we DO NOT deliver anywhere. Pickup only from Doncaster


  Q  How much Co2 does your normal size bottles hold?

A Co2 is sold by Liquid wieght the standard pub bottle is filled to 6,46kg (14lbs in wieght) If they were filled by pressure you would only get about 1kg of gas but we pump liquid Co2 to fill to 6.00kg.

All our cylinders are SAFE in date and Tested 

Q  I have an out of date bottle that I was thinking of trading in for a co2 nitrogen mix. would I need another regulator for mixed gas or can I use the same regulator ? Mark A

A The regulator is ok, you just need the adapter to change from a male fitting to a female fitting they used to be available from ‘Machine Mart’ but eBay may be the best place now. Look at Homebrew Page the two colour cylinder is a ‘mixed gas’ cylinder look at the valve it's a female fitting on the bottle. Pubs in general use a 60/40 Co2/Nitrogen mix for most beers only using Co2 for light lagers.We do not carry stock of mixed gas cylinders.

Q   bottle which I bought off eBay.This didn't come with test certificate, how much would it cost to have the bottle retested? Mick C

A Sorry but the best we can offer is a £5 trade in on a refurbished cylinder

 Q  How much for a full bottle with gas and would you delivery to knaresborough north yorkshire

A Sorry mate, can’t afford to deliver at these prices. That’s why everyone wants you to rent the bottles ‘£50 to £60 year’ and they will deliver!! There are plenty of companies who will fill these bottles for you (Our bottles say 'Rent Free' 'Purchased from Yorkshire Co2 Gas') So you don’t have to have them filled with us you just go to a local firm to fill it.

 Q  Do you know if co2 which u are using to refill bottles is ok to use in fish tanks and are u able to fill fire extinguisher up with your equipment??? eBay question

A This food grade Co2 is used for carbonating soft drinks, beers etc. and is the only one suitable for aquariums and fish tanks. Insofar as the fire extinuishers are concerned: They should have a date on when last tested, fire extinguishers have an automatic 5 year test unless specified.

Q i know you quote 14lb bottle how much co2 is in it eg. compared to a 2kg fire extinguisher i use co2 for my aquarium something this size will last me months hopefully if i got one from you i have work m8 who lives in doncaster who can pick it up I'm asking the co2 content because Cromwell tools will fill my 2kg extinguisher for around £24 i live nr leics. eBay question

A Firstly find somewhere else to fill your bottle. Search Google for ’ Leicester pub gas’ ‘Leicester co2 gas’ ask your local pub where he gets his filled, there will be at least 1 and probably 2 or 3 companies within easy driving distance from you. The problem is having your own cylinder within the test date and correctly labeled not filling them. A fire extinguisher being filled with 2kg of liquid Co2 should cost no more than £15 The standard pub cylinder are filled with 6.46kg of liquid Co2 therefore the pub cylinders hold more than 3times as much Co2 than your 2kg fire extinguisher.

We charge £20 per refill but charges with other gas stations would vary from £15 £30 per refill. There is a considerable difference in size the pub bottles are about 34inch (850mm) high X 6 inch (150mm). Must be stood vertical and securely fastened.

Q I understand these can’t be couriered because of the gas in them, is it possible to send these if there were dismantled? I could arrange a courier to collect them if this was possible.

A They can’t be dismantled: a solid cylinder with valve and handle. That’s it Test certificate is for the test on the cylinder with valve attached. Remove and replace valve and the test is invalidated and is highly dangerous.

Q Can you supply pure Argon?  

A Sorry only Co2 gas. Our customers have changed over from argon due to the exceedingly high cost, availability and difficulty in having bottles re-charged

Q Could you tell me how many liters your bottles hold just for comparison, thanks

A The bottles vary from 8 to 10 liters but are all filled with 6.46kg of liquid Co2.

Co2 is always sold by weight (liquid) not by volume (gas) 1 kg of liquid Co2 when expanded to atmospheric pressure would equal 550 litres

All our cylinders are SAFE in date and Tested

Q HI there, Can these cylinders be filled with other gases like argon for welding.

A The cylinders we have are for: Co2; single gas, all grey or all black Co2/Nitrogen; mixed gas green on top grey or black on bottom. All cylinders are colour coded for the gas which they have been tested for. So the answer to your question is no, only cylinders which have been tested for Argon and are the correct colour (all green) with a female fitting can be used and filled with Argon. No gas supplier would even dream of filling a cylinder with a gas that the cylinder hadn’t been tested for (extremely dangerous).

Q Is this bottle can be used for charging gas to air rifle as well?

A They would use the liquid Co2 for paintball guns, don’t know about Co2 for air rifles

Q Do you do argon/co2 mix for mig welding if so is it the same price???

A Sorry Co2 bottles only

Q Hi Do you have a co2 bottle that will fit JBL co2 system for aquarium? or could you refill a co2 bottle for me if I sent it in? Thanks

A Collection and delivery to and from Doncaster only. Depends on the fitting if we can fill it also on the safety date.

Q Would you be able to refill my 2 KILO CYLINDER. It has been tested How much would the refill be ?

A Yes we can fill your cylinder providing there is some form of safety collar or test date stamped on the bottle to prove expiry date, The minimum charge is £10

Q Just looking for some welding gas, I’m based in Garforth in Leeds and managed to find you on eBay. 2 quick questions, do you have any bottles at the moment and do you deliver to my area or do I need to collect?  

A Yes we have pub size Co2 bottles at the mo and sorry collection only from Doncaster

Q I’m looking for a CO2 bottle and regulator for pressuring a Cornelius keg (homebrew) , do you currently have any in stock? If so do you have the double gauge regulators both showing psi? Could you please let me know your prices for bottle, gas and regulator, and your address?

Q Hi, I'm wanting to get a CO2 cylinder to fit to a Cornelius keg, however am unsure as to what regulator and fittings to use (have ball lock fittings on my keg). Do you supply fittings etc? I'm hoping to be in your area tomorrow if you're available. Cheers, Neale  

A Co2 regulators are all standard fittings, male fitting on the cylinder, female on the regulator, thread sizes are all the same. We have about 20 in stock at the mo.

Q Hello, I have a Clarke 120E mk2 mig welder that uses the little disposable gas bottles, I would like to use a decent size bottle but would also need a regulator. Do you have a suitable regulator available? Many thanks

A We have Co2 bottles in stock 6.00kg 15.00kg and 22.5kg, price varies according to size, we usually have the regulators for sale.

Q Do you fill the paintball bottles if so how much???

A No we don’t fill the gun but we do sell the liquid Co2 cylinders with the dip tube in. Check out our ‘liquid Co2’ page.

Q Looking at your add on eBay. Am I able to collect and pay for a gas bottle over the weekend. I am in Grimsby. Cheers Steve

A No probs. You can collect from the house, just give us a call before you set off. 

Available 7 Days a Week Mon-Sat 10:30am to 7:30pm, Sunday After12:00 noon 

Q Hello this might be a silly question, but is food grade co2 also suitable for welding? if so do you have a contact number so i can arrange collection of 1? regards. spencer

A All the Co2 sold in pub type bottles is ‘food grade’ Co2 and this is the best Co2 for welding (few if any impurities) Doncaster 01302 366332

Q I have a mig welder and use the small disposable canisters, If I bought a Co2 bottle would I get my deposit back when I returned it??

A We don’t take a deposit you buy the cylinder and can fill it anywhere and if you finish with welding you can sell it on eBay. 

Q Good morning, i want to know the price of this bottle, but empty, and if you can send it to:


Norfolk XX24 XXA United Kingdom

A Sorry we cannot send these bottles out by courier, collection only from Doncaster.

Q i have an empty Co2/Nitrogen bottle (internal threads) but need a Co2 bottle (full - with external threads) and a regulator, would you be able to make a special price for exchanging my old bottle for new Co2 full with a regulator, thanks

A Yes bring it in and you can trade it in on a newly refurbished bottle.

Good evening, i wonder if you could help me please? My BOC argon cylinder has run out and i cannot seem to get it exchanged anywhere, i am looking to change over to co2 in which i have a cylinder but looks like the test dates have expired. Do you do the retesting of the cylinders please ? i am quite desperate to get my mig welder up and running again, looking forward to your reply, thank you regards Steve.

A Return your BOC cylinder to BOC it's their property.

Retesting price is the same as trading your cylinder in for a refurbished and newly tested bottle.

All our cylinders are SAFE in date and Tested


Hassle Free Filling

Fill at your local filling station

Co2 cylinder label showing: ‘rent free’, purchased from Yorkshire Co2 gas. Carbon dioxide ‘E290’, Co2 ‘1013’, fire hazard ‘2’, emergency phone number

You can fill our cylinders anywhere

Phone 01302 366332

All our cylinders are SAFE in date and Tested