Thomas Glover 2kg CO2 Extinguishers & 26/4/13 Update - Now on Chubb CO2's

[Psuedonym]

How are you getting on with PJ? They're our sole supplier of refurb Co2's too so it would be helpful to know of any issues. They provide good quality kit, so good our trained and qualified engineers lot put them in as "New"    I've not noticed any problems but I've only been back doing cans for a month now but no ones mentioned anything.

[lancsfirepro]

Have to wait for my client to contact the extinguisher maintenance company, who will need to attend site to swap over the cans and then approach PJ with them.  Just keep an eye out for oily gummy stains around the neck seal and have a close look; if you see bubbles you've got a problem.

[Psuedonym]

I found a PJ 2Kg Co2 yesterday with the same issues. Couldn't photograph it though it was on one of those "may we take you're mobile please sir?" sites. Anyway I was thinking, you probably saw the smoke on the M62 Eastbound yesterday, caused a bit of a queue apparently;
Is the brown material merely exposed threading grease used during installation? We've all seen PFTE in the past on refurbs, so why not a grease. I used it on Ansul pipework threading before jumping ship to assist threading the stainless steel pipe it's the same principal when applying a valve to the cylinder neck. Heat is generated therefore threads may not form correctly thus a threading material is required. This becomes liquefied in the process and then cools down perhaps leaving bubbles on the neck of a can.
Maybe observing specific Co2's is the answer. If they continue to bubble, they're leaking. If the threading material is solidified and does not increase then there's no issue.

The next question is therefore what is allowed to be used during valve installation? I've not took any courses for a while so don't have any up to date paperwork to refer to.

[lancsfirepro]

The extinguishers in question are Aluminium cylinders - the extinguishers you have seen with PTFE tape around the threads are steel cylinders.  Steel cylinders have valves with tapered threads and may use a sealing liquid or as you suggest, PTFE.  The actual sealing point of the valve to the cylinder is on the thread.  (You can see threads on the valves of steel cylinders.)  Extinguishers with Aluminium cylinders have valves with parallel threads and so require an o-ring to seal (you can't see valve threads fitted to an Aluminium cylinder).  See below, steel on the left.



Any cutting fluid that may have been used should be removed in the degreasing operation prior to powder coating.
Just to be clear, any CO2's I've mentioned as leaking were visibly producing bubbles.  Confirmation from TG suggest the o-ring is at fault and they have since been changed.

[Psuedonym]

Different metals and threading types eh? thanks for that. That's why I like these forums, they're a great source of information.

Seriously though, is there still a limitation the maximum threads visible above the neck - on the steel units obviously? Last I heard it was less than the number in the example  i.e. any more than two were not allowed.

Cutting fluid/grease is not a sealant and unknown to many, neither is PTFE never was and never will be. It melts under combined heat and pressure on the threads. Forms fluid and aids the reduction in friction or as in this case, by not allowing either valve nor unit threads to be damaged. The PTFE we see has not been subjected to these pressures and remains therefore a solid white tape that we all know.

I only offered a suggestion that the brown stuff could be a threading fluid. I'm as open to any suggestion or confirmation by the companies involved as anyone else.

Do we replace guilty units off site as a precaution until we get the all clear? Who will give written instructions for this?

 

ps I've a theory but physical problems, certainly not chemical. Co2 reacting with o rings??

[lancsfirepro]

CO2 reacting with certain types of rubber is a fact, not theory. 
For the avoidance of doubt, PTFE tape reduces friction when mating threaded parts together. It's not a sealant by design (although it helps to a degree), but aids sealing by allowing greater forces to be exerted on the threads which in turns creates the seal.

You can leave CO2 extinguishers with visible leaks in service if you wish; our clients will have them changed under manufacturer's warranty. I'm not really sure why this is causing too much confusion... it's pretty simple; faulty extinguishers get replaced under warranty.

[kurnal]

What is the manufacturers current angle on this Gareth? Their stance seems to have softened during the life of the thread, do we have any idea how widespread the problem is?

[lancsfirepro]

TG knew they had a problem, changed the o-ring and are exchanging leakers with new ones. Heard nothing from the FIA about the issue with Chubb. Still waiting to hear what PJ have to say but their MD is away on hols.

[Psuedonym]

U.I.G. CO2 MSDS:

Incompatible substances:   
Alkali metals.   
Chromium.   
Metal acetylides.   
Alkaline earth metals.   
Titanium above 550°C.   
Uranium above 750°C.

Oh, and now to save certain extinguisher manufacturers embarrassment for reducing the quality of their procucts : rubber o' rings.   
 

[lancsfirepro]

What's your point?

[TFEM]

I think pseudonyms point is that o rings cannot possibly react adversely with CO2 and lists those products that do react with CO2.
I understand that PJ have their own factory so how can TG/Chubb have the same problem?
And what's changed? Why now? Its not a problem that's been about for years.

John

[Psuedonym]

Sorry I wasn't clearer guys, thanks John.

On the same subject, I serviced one site today with 14 2007 TG parallel thread 2Kg co2's.
All serviced since 2007 by 4 differing companies, all responsible companies whose standard of work I've been aware of for years and would trust.

Each extinguisher weighed exactly the same today (digital scales) since the install date and the stamped weight and the same weight on each years' service.

Importantly, each extinguisher had the same brown substance around the neck of the unit below the valve.

So...my point to this post is, despite the substance, there appears to be no weight loss i.e. content loss from the units based upon reports from competent engineers continued servicing and thus this material is only overflow from the unit production.

So the kit stayed in situ as no fault was found.

Now then, if a manufacturer say they are aware of a fault and have now rectified it yet not issued a previous product recall and thus have knowingly sold faulty kit and left faulty fire protection products without recalling (which I seriously doubt as the company in question strives for  global quality company/product perception) : That's a problem.

[lancsfirepro]

Hmmm, it seems that you are having a hard time believing what I am putting forward.  For what reason, I am unsure.

Surely the list of incompatible materials is a list of what materials (and conditions - high temps) that the substance is unsafe at/with?  Not what it may react with slowly over time?  As in Material SAFETY data sheet.

Have a look at a data sheet for an o-ring here - note point 10 (Hazardous decomposition) http://www.edwardsvacuum.com/uploadedFiles/Resource/MSDS/O%20Rings%20-%20Nitrile%20&%20Rubber%20Tubing.pdf
It is a fact that carbon dioxide will attack certain rubbers.

The explanation that TG have put forward to certain trade bodies is that the o-rings they have used absorbed CO2 but then sealed; they state that the absorbed CO2 leaches out over time which may give the appearance of leaking.  Their stance is that they insist that any initial leak should very soon after stop and so there is no issue.  They have also said that they have looked into a number of returned extinguishers and found them not to be leaking, but that any client may return their extinguishers for investigation.  They say they have since changed the offending o-ring to one that does not absorb CO2.
None of this I am buying; they state the problem affects extinguishers dated the end of 2011 and early 2012.  This short window strongly suggests the wrong o-ring has been used and the o-ring continues to be attacked - why should it stop being attacked once started?
I wish to add that when I suggested looking for the brown oily substance around the valve to identify these extinguishers, this is the easy way to identify a potential leaking extinguisher - you would further need to determine whether signs of leaking are evident - i.e. bubbles.

[TFEM]

Gareth.....this is not a case of suggesting that lancsfirepro talking rubbish. I believe what you're saying, I've seen the evidence. I can see the problem. I just don't understand why its happening now all of a sudden.
We as a company survive by providing a quality service at competitive rates without the pressure selling that many of the brand names seem to earn millions from. I'm currently advising customers that, in accordance with the latest 5306 Part 8, they should be replacing their powder extinguishers because of visibility/contamination problems, that they should be having an extra wet chemical extinguisher because somebody has decided that the surface area of a deep fryer is more relevant than the quantity in it and now I've got to tell them that they've got to replace their CO2's because of some gunk round the neck.
I just need to understand what the problem is exactly, why its happening all of a sudden and what the manufacturers are doing about it so I can say "look Mr Customer, its not me ripping you off all the time".
Why are they leaking all of a sudden? Are the manufacturers trying to save a penny per product by using an inferior seal? Will the manufacturers replace the unit FOC?
John

[AnthonyB]

It is odd that we have had aluminium CO2 extinguishers in the UK since Kidde introduced them in the 60's, rapidly followed by the founder companies that became Chubb and not had a problem like this before. Cracked necks were all the rage at one time, now it's O-rings.

There must be a connection, it can't be coincidence - 2010 saw the Jactone leakers, shortly followed by the TG/Chubb gunky leakers and even PJ.

Manufacture and assembly for these was both in China and UK dependant on company, but where did they all get their O-rings from?

Perhaps it could be traced as far back as a certain batch of rubber used by a certain handful of o ring manufacturers?

Without a consistent industry wide statement from all the relevant players it's going to be a pain.

I can see the issue with dealing with the Customer as a lot of the latest BS5306-8 seems very purely sales driven as oppose to scientific (about the only bit I agree with is the powder clause)