CO2 Cylinder nut size

[josh18t]

Hey guys,

I recently got a small co2 tank from BOC and a co2 regulator off ebay.

I tried to fit it today and I cant get it to catch on there it jumps off after about 3/4 of a turn so Im guessing that the regulator I bought doesn't have the correct size nut for the tank.

Is there anywhere that I could but a new nut to connect my regulator to my tank? Ideally somewhere I could buy one around east London tomorrow? Also is there a way to find out the size I will need from the tank itself?

This is the regulator that I bought incase anyone knows any issues with this particular one :

https://www.ebay.co.uk/itm/Dual-Gau...e=STRK:MEBIDX:IT&_trksid=p2057872.m2749.l2649

 

[peebee]

Describes itself as having a G1/2 thread (1/2" BSPP). Very odd, UK CO2 cylinders are all W21.8 (a weird size, "W" stands for imperial Whitworth, IIRC it's 14 threads per inch, and 21.8 is metric millimetres).

It doesn't fit. Don't try and make it fit! CO2 cylinders are about 60BAR pressure (that is "quite a lot"). You can get adapters, but China is the most likely source which wont help if you want it tomorrow.

Australian Sodastream cylinders have G1/2 thread - but you didn't want to know that!

 

[peebee]

A bit more …

The full designation for the CO2 cylinder thread is "DIN 477 / JIS M22-14 / BS 341 No. 8 / W21.8-14 / .860" x 1/14" which is basically a list of "compatible" threads. Notice the M22-14: That's 22mm and 14 threads-per-inch … there is no limit to the insanity surrounding this thread! I've used G5/8 (BSPP again, but a rare size) to mate with the thread using a good bit of PTFE tape, but that was for a joint holding no more than 60PSI (I wouldn't try it with 60BAR).

Sorry, couldn't find a local source of W21.8-to-G1/2 adapters.

 

[soupdragon]

Can't comment about the regulator, sorry.
I will say that I hope you have better luck getting the BOC bottle refilled than I've had. Every place I asked wouldn't touch them as there's some sort of agreement that only BOC will fill their tanks. Unless you have an account with them that is.
Best of luck

Cheers. Tom

 

[BarnBrian]

Not a good idea to force any fittings that are involved with pressurised gas. If a spanner is needed to screw it all the way down then there's something wrong.

 

[peebee]

Not a good idea to force any fittings that are involved with pressurised gas. If a spanner is needed to screw it all the way down then there's something wrong.

'Tis no good, you can't tell some people. There are those who need an up close practical demonstration of what 60 BAR (870 PSI) can do. Like I've had a practical demonstration of what landing on my head at a decent speed can do.

But I survived my demonstration...

 

[Dutto]

It doesn't take a high pressure to kill someone.

Pressure = Force ÷ Area therefore Force = Pressure x Area

So a lad stood on the cover of a 24" diameter check-valve with only 5psi of air pressure in the line it was serving.

Having removed all of the bolts the cover was still held in place by the gasket so the young mechanic (still standing on the cover) decided to stick a chisel in to the joint and hit it with a hammer to release the cover.

The Formula to calculate the area of a circle is πr2, in this case 3.142 x 12 x 12 = 452 square inches. Multiplied by the 5psi of pressure the Force pushing up against the cover when it was released was 2,260 pounds.

The check-valve was some 30 feet up in the air and the force was sufficient to lift the cover up and crush the lad against a roof support just above his head. The pathologist reckoned that his crushed skull was the cause of death and that he was dead before he hit the ground.

That was at a pressure of ONLY five pounds per square inch!

 

[marlon]

WOW..!! Thanks lads! I had no idea - already disconnected it this morning!
So now I'm in the same boat as Josh....

 

[BarnBrian]

It must be at least forty years since Dutto and I have been called lads.

 

[josh18t]

Thanks for the replies guys. There was no way I was messing around with connections on this sort of pressure.

It’s very confusing with all the names of the fittings. I spoke to a couple of welding companies, all of them told me that sourcing the nut would probably end up more expensive than buying a new regulator so I’ve ordered this one off eBay:

https://rover.ebay.com/rover/0/0/0?mpre=https://www.ebay.co.uk/ulk/itm/282615479560

It says w21.8 and states UK co2 so hopefully this will fit. In the meantime I’ll order a new nut from China and can either resell it or keep it as a spare regulator.

Does this regulator look like it’ll do the job?

 

[BarnBrian]

Afraid you're not having much luck. You need one with an outlet pressure of around 50 psi max. The one you've ordered doesn't have a pressure gauge on the low pressure side, it's a flow gauge. It also says on the gauge 0-10 bar. 10 bars being 145 psi.
If you're not technically minded it's best to go straight to one of the brew shops. It may be more expensive but I think it's going to save you money in the long run.

Brian

Thanks for the replies guys. There was no way I was messing around with connections on this sort of pressure.

It’s very confusing with all the names of the fittings. I spoke to a couple of welding companies, all of them told me that sourcing the nut would probably end up more expensive than buying a new regulator so I’ve ordered this one off eBay:

https://rover.ebay.com/rover/0/0/0?mpre=https://www.ebay.co.uk/ulk/itm/282615479560

It says w21.8 and states UK co2 so hopefully this will fit. In the meantime I’ll order a new nut from China and can either resell it or keep it as a spare regulator.

Does this regulator look like it’ll do the job?

 

[josh18t]

Damn thanks for that it’s really annoying as I’m obviously in a rush to get it sorted and was too hastey.

Do you think I could just take the inlet nut off this one and put it on my other regulator?

 

[Oneiroi]

I ordered an almost identical model, but haven't got a gas bottle to try it on yet. The ad describes it as W21.8 but I tried to fit it to an old co2 fire extinguisher, which I read had the same thread type, and had the same problem as you.

What kind of nut were you going to order? something like This?

 

[BarnBrian]

Hi Josh
You may be lucky. You can't just remove the nut you will need to unscrew the stem from the regulator and use that stem and nut. When you screw the stem into the regulator (assuming it's the same thread) get some PTFE tape and wrap two to three turns around the thread before screwing it in, this will assist in getting a decent seal. If the stem doesn't have flats to take a spanner then you will need to use vice grips (Mole grips) or stilson's to remove and replace the stem. Vice grips are probably your best bet as I'm guessing you've never used stilsons. If you know anyone who's a bit technically minded you might ask for assistance.
Where are you based, someone here might be able to assist?

Brian

 

[BarnBrian]

As both Dutto and PeeBee have said, working with pressurised gases have the potential to be dangerous, so messing about changing nuts, fittings etc is not the wisest thing to do unless you have some prior knowledge. I've worked for over 45 years in the oil and gas industry, firstly as a saturation diver and currently managing a deepwater construction vessel. I've seen six people die from various pressure related failures so I treat anything under pressure with the greatest respect

 

[josh18t]

Thanks Brian,

I’m technically minded but unfortunately that’s just for sound engineering and electronics not gas

I’ve got a desk mounted vice, PTFE and spanner at home so will give it a go. But I have just seen that keg kingdom are on Amazon prime so biting the bullet and paying a bit more would have defiantly been easier and far faster.

Yeah that’s the one I was looking at or very similar on AliExpress Oneiroi.

 

[peebee]

Having told folk a G1/2 (female) to W21.8 (male) adapter is what you want, damned if I can find one now! Here's some adapters:
https://www.ebay.co.uk/itm/CO2-Cyli...hash=item3f813835c4:m:mc7w5XExKcC64t3AQFng0eg
BUT … they are for G5/8 so wont fit to G1/2. Does illustrate what you might look for.

… What kind of nut were you going to order? something like This?

Better than an adapter is to replace the entire stem and nut. But you have to be absolutely sure you can remove the original stem (they are fitted in the knowledge they wont be removed again), that it has the right threads and be confident you are doing everything right. The one linked says 1/4" NPT. Chinese stuff is often NPT (an American tapered thread) but can you be sure 1/4" NPT is what you want?


I've got a barely used suitable regulator if anyone wants to make an offer (something to get me off me bum, go find it, pack it in a box and walk around to the PO with it). Like this https://www.ebay.co.uk/itm/Co2-Sing...292733?hash=item2147f708bd:g:SyMAAOSwNSxU~0y2. I moved onto fancier kit - believe me, you don't want to be going down that road (https://www.thehomebrewforum.co.uk/threads/bar-build.78269/).

 

[The Baron]

Thanks Brian,

I’m technically minded but unfortunately that’s just for sound engineering and electronics not gas

I’ve got a desk mounted vice, PTFE and spanner at home so will give it a go. But I have just seen that keg kingdom are on Amazon prime so biting the bullet and paying a bit more would have defiantly been easier and far faster.

Yeah that’s the one I was looking at or very similar on AliExpress Oneiroi.

Josh before you order from Keg Kingdom read the posts re them on this forum just incase you want it quick

 

[Dutto]

It may be more expensive, but it sure as heck was simple!

My system comprises:

• A Sodastream CO2 bottle because it's available all over the UK.
• An adaptor to get the Sodastream to fit the Dark Farms Pressure Regulator.
• The Dark Farm Regulator.
• A "Y" piece.
• Two compressed air female connections.
• Two compressed air male connections.
• The end off an old bicycle pump.
• A few metres of plastic tubing and some Jubilee Clips.

It looks like this to the Growler ...

... adjustable from 5ps to 30psi the Pressure regulator feeds to the "Y" piece ...

... and the second connection is used to pressurise the various PB's using the old bike pump.

When not in use, the CO2 in the tubing doesn't leak out because the end of the air connection fits into the bike connection.

Genius eh?

Total cost for the set-up was about £45 and despite a series of "tests" and "screw-ups" the original Sodastream bottle lasted over six weeks; so I expect the replacement to last at least twelve weeks during normal operation. At £15 for a replacement cylinder I consider it to be well worth the expense and effort.

 

[BarnBrian]

It may be more expensive, but it sure as heck was simple!

My system comprises:

• A Sodastream CO2 bottle because it's available all over the UK.
• An adaptor to get the Sodastream to fit the Dark Farms Pressure Regulator.
• The Dark Farm Regulator.
• A "Y" piece.
• Two compressed air female connections.
• Two compressed air male connections.
• The end off an old bicycle pump.
• A few metres of plastic tubing and some Jubilee Clips.

It looks like this to the Growler ...

View attachment 15730

... adjustable from 5ps to 30psi the Pressure regulator feeds to the "Y" piece ...

View attachment 15731

... and the second connection is used to pressurise the various PB's using the old bike pump.

View attachment 15732

When not in use, the CO2 in the tubing doesn't leak out because the end of the air connection fits into the bike connection.

Genius eh?

Total cost for the set-up was about £45 and despite a series of "tests" and "screw-ups" the original Sodastream bottle lasted over six weeks; so I expect the replacement to last at least twelve weeks during normal operation. At £15 for a replacement cylinder I consider it to be well worth the expense and effort.

Hi Dutto
I refill my sodastream cylinders using an adapter from CO2Supermarket, not cheap to set up initially but saves money in the long run.