Co2 Cylinder Screw-down Valve: Your Worst Nightmare

[cooperplace]

Like lots of people, I use a fire extinguisher (with pickup tube removed) to gas my kegs. I squeeze the 2 levers to turn on the CO2. BUT, the tiny little valve inside is doing a completely different job from that which it was designed for. As an extinguisher, it has intermittent use at most, but I use it all the time. So I'm having to have the valve rebuilt every time it is refilled.

Why not fit a screw down valve, you say?

First, the valves used on beverage CO2 cylinders are completely different and don't fit.

I've spent the day on the phone and at the workshop of my friendly fire extinguisher guy, trying to work out how to do it. He told me that there about 8 different threads on C02 extinguisher cylinders in Australia, not including aluminium-bodied valves, now condemned.

My extinguisher is a 3.5kg Chubb, made in Sydney in 1988. It's aluminium, they nearly all are. What sort of thread does it have? I called Chubb, and eventually found someone in Chubb Melbourne who told me that they were made for Chubb by CIG, now BOC. I called BOC, an exercise in frustration until I got onto the wonderful Eleanor in customer service who said that the extinguisher factory was taken over by Luxfer in 1989, and gave me the Luxfer number.

So I called Luxfer and spoke to a very switched-on lady, I don't know her name, who said, yes, it will have either a 1" taper, 14 threads/inch, or a parallel thread, 3/4" NGS. And that if the flange on the valve is pushed down hard onto the shoulder at the top of the tank (no threads showing), it is parallel. If threads are showing (they're not) it is taper. The numbers stamped on the extinguisher don't help, she said, as CIG used the same numbers for two different extinguishers.

As an aside, blokes, please note that the best information came from the two ladies I spoke with.

Interestingly my extinguisher guy has given me a lever-type valve identical to mine (my cylinder is stilll half-full so I'm leaving it alone for now) and I found that a 3/4" BSB female compression fitting screws 99.9% perfectly onto it. It just seems a teensy weensy bit loose. Is that acceptable with CO2 under pressure?? Ha ha I think not.

So now I know that my cylinder has the very unusual 3/4" NGS (national gas straight, a US std) so I must get a valve with that, and an Oz type 30 outlet. What are my chances?

I am trying Gas Cylinders UK who claim they can find a valve for any thread

http://gascylindersuk.co.uk/store/catalog/...b6fac0a6aa5b6b8

but I'm not holding my breath.

I could go mad if this goes on. It might be easier to buy Ebay item 280345152266, 2.6 kg cylinder for sale for $149.95 from Beerbrewonline, (complete with screw down valve) and they have regulators for $60, great prices. BTW I have no affiliation whatsoever with these people, indeed I've never spoken with them.

If I get a good reply from Gas Cylinders UK when I call them tonight, I'll do another post asking if anyone else can use such a valve.

Meanwhile, does anyone know of some place local where I could get a CO2 screw-down valve with 3/4 NGS on the cylinder side and type 30 on the outlet?

Peter

 

[manudh]

I could probably make you an adapter from the exotic threads you use to the more common threading used in valves
-> http://www.stainlessstuff.net

 

[bigfridge]

Like lots of people, I use a fire extinguisher (with pickup tube removed) to gas my kegs. I squeeze the 2 levers to turn on the CO2. BUT, the tiny little valve inside is doing a completely different job from that which it was designed for. As an extinguisher, it has intermittent use at most, but I use it all the time. So I'm having to have the valve rebuilt every time it is refilled.

...

Meanwhile, does anyone know of some place local where I could get a CO2 screw-down valve with 3/4 NGS on the cylinder side and type 30 on the outlet?

Peter

Hi Peter,

Thanks for your very detailed post - it really tells the story.

I would suggest that you can easily buy a valve from someone like kegs-on-legs (available from your local brew shop) and you will find that the valve comes with a free, fully tested, new cylinder attached as a bonus.



It really concerns me that people are taking a device designed for occasional use and using it for gassing kegs on almost a daily basis. If fire extinguishers need to be inspected on a yearly basis when they haven't been used, how often do you think that they should be inspected if they are used regularly.

HTH
David

 

[TidalPete]

Very interesting.
Take a look HERE

TP

 

[cooperplace]

Hi Peter,

Thanks for your very detailed post - it really tells the story.

I would suggest that you can easily buy a valve from someone like kegs-on-legs (available from your local brew shop) and you will find that the valve comes with a free, fully tested, new cylinder attached as a bonus.



It really concerns me that people are taking a device designed for occasional use and using it for gassing kegs on almost a daily basis. If fire extinguishers need to be inspected on a yearly basis when they haven't been used, how often do you think that they should be inspected if they are used regularly.

HTH
David

You make a good point. I'm very aware that high-pressure gas is to be taken seriously, and yes, the brand-new tank + valve looks attractive,

Peter

 

[smollocks]

Why not just buy the screw-down valve you want, and have someone tap a compatible female thread into the neck of the extinguisher?

 

[browndog]

Why not just buy the screw-down valve you want, and have someone tap a compatible female thread into the neck of the extinguisher?

Even if you went to such a rediculous amount of trouble to get an adapter to fit a screw down valve to a fire extinguisher, do you think anyone with a brain in their head is going to fill it for him? I think not.

cheers

Browndog

 

[claymen]

Honestly so long as the integrity is maintained and a cylinder place can stamp it then no one should care. This is what shits me a little bit, seems that there are plenty of places to get cheap tanks but the major refilling places won't touch any "unknown" brand tanks even if they are 100% legal and stamped properly. It honestly comes across as the big boys trying to price fix the tanks.

A tank is a tank, if its tested ok what is the damn issue?

 

[Linz]

Guys,
from being in the fire industry...the point some may have missed is..Bugger the pressure its under, It boils off at -85oC..Instant frost bite, bits turning black before your very eyes and falling off, on to the floor in front of you.

I do have a video somewhere showing a 5.0kg CO2 bottle(full) being shot from distance and discharging its contents.

.also have been no more than 8ft from a 3.5kg co2 let go(safety device/bursting disc) due to excessive heat of direct sunlight!

 

[cooperplace]

Hi everyone,

I've just been talking to Gas Cylinders UK (the website claims: "valves available for any thread size on request") but guess what: "NGS 3/4", no sorry, we only do the standard one" so it looks like I'll be buying a new CO2 cylinder from a retailer, as discussed above.

Also, I've been viewing an interesting video on U-tube:



Admittedly it is an O2 cylinder that exploded, but heck, the pressure's the issue. It ripped the guy's arm off. It makes you think.

Peter

 

[crundle]

I have been doing some research on this issue also, and have had the thread measured on the neck of my 5kg fire extinguisher as being 3/4" BSP (parallel). The type 30 fittings are 3/4" tapered. This presents a problem in that no one seems to be able to say with certainty whether or not a tapered fitting is suitable for use in a parallel thread, but my research has shown that according to ISO standards, tapered fittings are OK to use in parallel threads, as the seal is made by the thread itself, unlike the parallel fitting on my fire extinguisher currently, which seals at the end of the thread and was not a very tight fitting to undo when the bottle was empty.

The question that I am asking myself is, is it worth the money to get a type 30 fitting and it may or may not seal properly anyway (financial concern), and is it worth the money to take the risk that it may let go on me one day?

I think this is a question for each person individually. I know of some people who have used the type 30 fittings successfully, so I assume they do work, but just as those who don't consider it safe to use fire extinguishers per se may have a higher safety threshold than myself, is the use of a fitting not designed for a fire extinguisher a bridge too far in comparison with using a fire extinguisher's original parts in a role they were not designed for?

I have had the small valve in the top of the fire extinguisher pin go on me 4 times now. I have heard that you can use a slightly larger O ring on the valve and this can fix the problem, but I am unaware of what size it needs to be, so this may be an alternate way around the problem.

Here are some pics of the thread in the neck of the extinguisher



Here is the trigger assembled


Here is the inside of the trigger head looking from below


The valve stem


The base of the valve - this is designed to be closed for long periods and held in place by the spring


The top O ring - this is the bit that often fails me, and is probably designed to seal gas from exiting the trigger plunger for the time it takes to empty an extinguisher (60 seconds?) If this was replaced with a larger O ring, it may seal more effectively. think of it this way, if the original can seal for 6 months in the open position when it is designed to only work for 60 seconds, then a *slightly* larger one should hold for much longer again before it finally fails.


Exploded view


It seems to make no difference to my setup whether or not I keep the gas on the whole time. When I use it on demand, I am making the valve (and the O ring) move up and down which eventually leads to gas leaking past the O ring - flat beer. If I leave it on the whole time (longest has been 6 months with no issues, then at random it seems to start losing gas), eventually the gas works its way past the O ring and again - flat beer.

Perhaps it is safer to look at the option of replacing the original issue O ring with one that will hold the seal longer rather than mucking about with threads that are difficult to identify firstly, and parts that are near impossible to come by secondly (type 30 fittings). vented gas is vented gas, but an O ring is far cheaper to replace than the head of the unit, and if it stops the leaks, then it is fine in my books.

I hope that one day we can sort out this problem, as I for one hate coming home and finding I have no gas in my kegs when I go to pour a beer.

Crundle

 

[bigfridge]

Also, I've been viewing an interesting video on U-tube:



Admittedly it is an O2 cylinder that exploded, but heck, the pressure's the issue. It ripped the guy's arm off. It makes you think.

Peter

Peter,

Compressed gasses is a complex area - one that should not be simplified or underestimated. There is a vast difference between CO2 and Oxygen cylinders. CO2 is a liquid in the cylinder under the normal pressure of 600 PSI. Oxygen remains a gas under a much greater pressure - 3,000 PSI from memory.

The transport and storage of these gases is a specialised area of engineering and tampering with the design parameters by 'cutting new threads' or 'fitting new valves' is a recipe for disaster. There may have been some justification years ago when there were few alternatives available but now there is no excuse to be foolish.

If you cant afford to purchase a cylinder designed and approved for Australian conditions then you shouldn't be kegging - bottles are much cheaper and less life threatening.

To steal a worthy quotation - Don't send your good brewers to heaven, as heaven knows we need them here !

Dave

 

[Leigh]

It astonishes me that people in this thread are annoyed when they come home to an empty CO2 extinguisher...do people realise that this is a lethal recipe? An extinguisher discharging in a small can lead to CO2 concentrations at levels that can cause asphyxiation...people may have a "high danger level", but should they be exposing the rest of their family/housemates/guests to this danger?

Sometimes I think homebrewers are tightarses, this thread goes a long way to proving that!

 

[mje1980]

Don't want to jump on the bandwagon, but playing around with pressurised containers is a bit crazy if you ask me. I rent one, it's 100 bucks a year, or 2 bucks a week, no big deal, and every 18 months i replace it with a full one for 40 bucks.

Obviously if you are miles from a gas place, it might make it difficult, but it's a bit of a risk.

 

[quincy]

QUOTE (bigfridge @ May 19 2009, 08:25 AM)
Hi Peter,

Thanks for your very detailed post - it really tells the story.

I would suggest that you can easily buy a valve from someone like kegs-on-legs (available from your local brew shop) and you will find that the valve comes with a free, fully tested, new cylinder attached as a bonus.



It really concerns me that people are taking a device designed for occasional use and using it for gassing kegs on almost a daily basis. If fire extinguishers need to be inspected on a yearly basis when they haven't been used, how often do you think that they should be inspected if they are used regularly.

HTH
David


Gotta agree with bigfridge.

I hire a D size "beergas"cylinder from BOC. Costs me $10.87 per month and refills are around $35. I refill about every 18 months.

Advantages:

1. Refills are completely hassle free.
2. I don't risk anyones safety - hate to think what might happen with a dodgy setup
3. If your concerned about cost, based on my circumstances, it's about $3 per keg. A small price to pay given the above 2 points.

Cheers
Q

 

[crundle]

It astonishes me that people in this thread are annoyed when they come home to an empty CO2 extinguisher...do people realise that this is a lethal recipe? An extinguisher discharging in a small can lead to CO2 concentrations at levels that can cause asphyxiation...people may have a "high danger level", but should they be exposing the rest of their family/housemates/guests to this danger?

Sometimes I think homebrewers are tightarses, this thread goes a long way to proving that!

My equipment is in an open area, so no issue with CO2 concentrations for me, but I get the point you are making, and it is valid. However, you can just as easily have a leak from the hoses or fittings with a commercially available cylinder, so both can be dangerous in regards to gas leaks.

Homebrewers tightarses? I would think most were in some regard, or many would never have started making their own beers. Sure, as they go along most learn to spend a bit more on better equipment or ingredients so as to make better quality beers, but there is still the incentive of making better beers for less money driving many people in homebrewing to this day.

In all the years that people have been using fire extinguishers to gas their kegs, I have not heard of any fatalities or near fatalities on this forum. The worst that seems to occur is that the extinguisher loses gas, and as this is a very real possibility, precautions such as location of the extinguisher and ventilation must be taken into account, but these are precautions that surely one would also take for a commercially available CO2 cylinder also if they were prudent.

I see no reason why people shouldn't experiment within reason to adapt an object to another use to make beer with. Safety concerns are the reason that I am hesitant to fit a type 30 valve to my extinguisher until I can be shown that it is at least no more dangerous than the existing fire extinguisher head for flying off. If it wasn't for such experimentation, we would not have BIAB or no chill cubing.

cheers,

Crundle

 

[claymen]

It astonishes me that people in this thread are annoyed when they come home to an empty CO2 extinguisher...do people realise that this is a lethal recipe? An extinguisher discharging in a small can lead to CO2 concentrations at levels that can cause asphyxiation...people may have a "high danger level", but should they be exposing the rest of their family/housemates/guests to this danger?

Sometimes I think homebrewers are tightarses, this thread goes a long way to proving that!

If you have a leak then you haven't done it properly in the first place, regardless of whether its a fire extinguisher or not if your seals are not done properly you will have the same issue.

Don't want to jump on the bandwagon, but playing around with pressurised containers is a bit crazy if you ask me. I rent one, it's 100 bucks a year, or 2 bucks a week, no big deal, and every 18 months i replace it with a full one for 40 bucks.

Obviously if you are miles from a gas place, it might make it difficult, but it's a bit of a risk.

Starts to add up over the course of a couple years.

Hi Peter,

Thanks for your very detailed post - it really tells the story.

I would suggest that you can easily buy a valve from someone like kegs-on-legs (available from your local brew shop) and you will find that the valve comes with a free, fully tested, new cylinder attached as a bonus.



It really concerns me that people are taking a device designed for occasional use and using it for gassing kegs on almost a daily basis. If fire extinguishers need to be inspected on a yearly basis when they haven't been used, how often do you think that they should be inspected if they are used regularly.

HTH
David

From memory the fire extinguishes are checked every year to make sure they have pressure so that in the event of an emergency they are actually usable. It doesn't hurt that they test them every year but its not because they are concerned of the tank exploding but more that they work when there is a fire. With that said I don't remember them ever taking the ones from our work away, they simply did a routine check onsite and stamped the tag which has 5 years of date stamp space on it.

In any case I picked up a CO2 tank 3.5kg for $160 from a local cylinder testing place. Looks like it might have been a fire extinguisher tank once upon a time but in any case it had all the correct fittings to suit your standard CO2 reg and is stamped and within code. He sells a lot of them to the homebrew guys so he knows what they are being used for and said its not an issue.

 

[Leigh]

Yes the risk is less when in a large or open area, but people consider this route need to understand the potential issues. Likewise a leak after the regulator will be much slower and much less dangerous than one before the regulator...it's a rate thing leading to a concentration thing...

I have no issue with a certified tester making a CO2 cylinder out of whatever is available that he knows is safe, it is the home tinkerers above that worry me...

So there are 10,000 members of this forum, how many have been injured by bottle bombs? How many have burned themselves severely while brewing? How many have electrocuted themselves while brewing? How many have died while brewing...Who tells us abouty the non fatal accidents? What happened to all those forum members that no longer post? Can you be certain you know the answers?

That said I'm sure it would make the news somewhere had someone died, but a lack of deaths does not reduce the risk. Having seen with my own eyes the aftermath of pressurised vessels letting go, I wouldn't take the risk of modifying a fire extinguisher myself...

 

[claymen]

Fair enough, its hard to tell whether people are against using fire extinguishers at all or whether its just the DIY aspect of it. Honestly I thought most people were smart enough to get the modifications done by a cylinder place such that its safe, then again really so long as the bottle itself isn't modified and correct adapters are used I don't see there being too much issue (assuming the fittings are suitable for pressurized gasses).

 

[MHB]

Being a refiller this is a subject that I have a vested interest in.
Workcover NSW has just put out some interim rulings, soon these will be finalised and adopted Australia wide.

Where it gets really interesting form my point of view is that the onus is being placed squarely on the shoulders of refillers to insure compliance with the relevant Australian standards (in this case AS 2030 and AS 1777C). Work Cover only has control/oversight of what happens in the "Work Place" so effectively selling non-compliant bottles to domestic users isn't illegal, refilling them is.

If you want all the details you can read the two Australian Standards referred to above, with particular reference to AS 2030.1-2009 Gas Cylinders Part1: General requirements (if you don't want to buy it most large municipal and educational libraries have access).

Where it gets really interesting is that Occupational Health and Safety Act 2000 and OHS Regulation 2001 must be adhered to, failure to comply can lead to penalties up to $27,500 that's just for filling noncompliant cylinders.
The following is an extract from an email I received on this topic:-

The above legislation sets out the minimum requirements for gas cylinders before they can be legally filled i.e. put under pressure these being:

1) The gas cylinder design must have a current design registration number from WorkCover (clauses 136 and 107)

2) the requirements of AS 2030.1-2009 Gas Cylinders Part1: General requirements must be adhered to ( clauses 129 and 140 ), one of the most relevant requirements regarding your question is stated at clause 6.1 Initial test station inspection and marking AS 2030.1 2009 that each gas cylinder shall be inspected by a certified gas cylinder test station prior to filling for the first time in Australia

and

the requirements of AS 2030.1 -2009 Part 5: Filling, inspection and testing of refillable cylinders clause 6.2 Verification of cylinder markings that each gas cylinder prior to filling, the filler shall verify that the gas cylinder carries a current , legible test mark of a certified test station.

Note: Because AS 2030 is a mandated stated standard called up in the OHS Regulation 2001 the word "shall" is to be taken to mean that it is a legal requirement.

In regard to penalties there are a wide range of compliance and enforcement actions that can be applied and these are spelt out in the relevant sections of the Occupational Health and Safety Act 2000 and OHS Regulation 2001. Both the OHS Regulation 2001 and the OHS Act can be accessed via the WorkCover website www.workcover.nsw.gov.au
Engineering Team WorkCover NSW
(NB, i have made some changes to formating, not content)

Further reading of point 1 indicates that no pressure vessel may be used for any purpose other than that for which the certificate was issued.
My reading of this clause leads me to believe that modifying a fire extinguisher for any other use is illegal.

Sorry, I'm not trying to be a nark, just remember that when you ask a refiller to top up your "illegal" bottle you are asking us to risk a $27,500 fine because you are too tight to spend a few hundred dollars on a proper bottle, don't be surprised if someone laughs in your face.

Mark
Marks Home Brew

MHB