Quality Control of Gas Cylinders

Robin

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Last year before we left on our summer cruise we replaced all 4 of our GAZ cylinders and all 4 were found to be overfull and wouldn't light the cooker burners. The gas blew too hard and the flame was beyond the flame failure sensor, this had happened once before so I knew we could overcome it by letting some gas out which we duly did. However it takes several goes each time to discover just how much to let out that it works without dumping too much of what must be the most expensive butane in the world.

This year we also left on our summer cruise with 4 full Gaz cylinders - same problem! We have had refills in between that were OK but on both occasions we had problems it was from the same delivery batch to our club marina. Another 2 friends had a similar problem with this years gas bought in July.

OK so I complained both via our marina and to Calor Centre in Poole who supply the club, I did this last year also. They just shrug it off and say it happens sometimes but they don't fill the cylinders (either Calor or Gaz) on site but it comes in from a 'depot'.

Now, being fed up with the price of Gaz I just altered our on board system and installed a Gaslow changeover set up that I can run off Calor, with 2 cylinders connected and just switch over when one runs out. Either or both of these cylinders could also be Gaz (for when we have no access to Calor like in France) by using adapters we have ready to use. We now carry 2 Calor 4.5kg(10lb) cylinders and 2 Gaz 907 (6lb) as well.

OK now last weekend SWMBO switched on the wrong (reserve) full Calor cylinder by mistake and it wouldn't work! The one she should have used was half empty and DID work. Fortunately her error means that we discovered a faulty cylinder before it mattered! The faulty one seemed full (spring balance weighed it as 22lbs with a cylinder weight of 12.5lbs as marked on it). I returned this yesterday and Calor Centre Poole replaced it with another full one, having opened the valve on the 'faulty' one and gas did come out. They tried to say it was too cold last weekend for it to work but that argument collapses because a half empty one worked OK and it wasn't cold anyway. So what is going on? Faulty cylinder valve? What about Quality Control????

Now we are apparently supposed to have a registered CORGI engineer do gas work these days rather than DIY. How does that ruling relate to the comments that you can 'just let some gas out if it's over full it happens sometimes'! It isn't so much hassle in our berth but just when does the gas run out that conveniently, changing and venting a faulty cylinder at sea heeled over and dying for a cuppa or a hot meal it is not so convenient!

BTW current butane price for Calor is £1.37 per lb of gas and the same gas in a Gaz 907 is £2.90 per lb of gas. Calor Gas UK are owned by Gaz and the same depot fills each cylinder with the same gas, the Gaz version is over double the price. Now I know we live here in Rip-Off UK but that surely is something the Office of (un)Fair Trading should look at!

[/rant over]
 
While you are having a rant about gaz incompetence and restrictive practices - how about the need for completely different regulators once you move from the standard calor to the next size up. (push on instead of screw on fitting.)
 
Yes, my thought too. Is this a regulator fault, rather than a bottle over-full? Or are the cooker nozzles incorrectly sized? or partially blocked?

Having bought obviously 'home-filled' Gaz bottles in Spain, Italy and Greece that have never failed in the way described, I would hesitate to blame UK factory filled bottles.
 
If the cylinder is overfilled OR allowed to tip so that liquid contacts the head / regulator - it will not pass gas - as author found out.
There must be a space above the liquid to allow vapour to be formed and ONLY vapour must hit the regulator.

It is one of the reasons that gas cylinders of any LPG form ---- Butane / Propane etc. must NOT be used straight after being rolled on side or tipped so that liquid hits valve head.

(We are LPG testers .......... /forums/images/graemlins/ooo.gif)
 
That must be some significant overfill then, I really can't see Gaz giving away that much extra on a regular basis - it would play havoc with profit margins. I would still be looking at the regulator.
 
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I really can't see Gaz giving away that much extra on a regular basis - it would play havoc with profit margins. I would still be looking at the regulator.

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or the cooker. None of this makes sense to me. In 20 years I havent once had this problemso my suspicion is that its a problem either with the regulator or the cooker.

Is the regulator on the bottle top or is it a remote one like all mine have been?
 
Unless things have changed recently, Colemans own Camping Gaz. Calor however have the contract to fill the cylinders at a central plant. Most cylinders in the UK are rental, but Camping Gaz, sell the cylinder to you.
 
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I really can't see Gaz giving away that much extra on a regular basis - it would play havoc with profit margins. I would still be looking at the regulator.


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or the cooker. None of this makes sense to me. In 20 years I havent once had this problemso my suspicion is that its a problem either with the regulator or the cooker.

Is the regulator on the bottle top or is it a remote one like all mine have been?

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OK so answering several comments and questions in one reply.

The cooker is a Force 10 designed for European use and has always worked well. Indeed it still does with the 'faulty' cylinders, once they have been vented to let out some gas.

As far as regulators are concerned, when the problem first arose I suspected a faulty regulator and even though I had got it working by venting gas, I bought a new regulator (in France, sold by Gaz themselves) and fitted this. The problem reappeared when the next cylinder was installed. These regulators were bottle mounted ones.

After using the rest of the batch of Gaz cylinders in August 2006, we bought at least 2 more that were quite OK, no venting needed.

We then bought 4 refills for use in July/August this year, all from the same source. All four of these behaved as before and needed venting.

Last month I fitted a Gaslow wall mounted brand new butane regulator and changeover system and switched initially to using one Calor and one Gaz cylinders. Firstly we ran the Gaz cylinder on outlet 2, this was a part cylinder left over and one that had been vented when in use on the old regulator setup, it worked perfectly. When the Gaz cylinder ran out we changed to the new full Calor Cylinder on outlet 2. The system worked fine with this Calor cylinder and no venting was needed. I then obtained another full Calor cylinder (same local source) which replaced the empty Gaz one on outlet 2. SWMBO mistakenly turned this one on last weekend instead of No1 - it lit at first on Friday night but on Saturday morning (temp about 8 degs C) it wouldn't light even when shaken. We switched to No1 Calor and it worked fine, no shaking needed. I later tried No2 again and it lit briefly then went out, so back to N01 which is fine. I've just traded No2 for another but confirmed that it WAS a full, not an empty supplied in error. Maybe dirt in the valve???

As for this not happening to others we have another club member who had the same problem from the same timeframe this year. Like me he suspected the regulator and bought a new one which didn't work either. He vented some gas and hey presto it worked. Another member has had the problem several times and just accepts it and vents some gas. Yet another has had the same problem but knew from my ranting last year what to do and vented some gas.

I've been using gas on boats for 35 years, mostly Calor but have always carried Gaz backups when cruising France. I have had occasional problems but never on the scale of these and of course we were using very few Gaz then versus Calor. Our current boat came however set up with Gaz alone, until I changed it last month.

As for Gaz worrying about margins since they are charging over double the price for theirs I think they are still quids in!!!

Oh and our cylinders are always stored upright on board and I do know not to allow liquid butane to get into the regulator.

The Calor Centre in Poole acknowledged that it happens, but pass the blame up the supply chain to the filling depot. They did promise this time to pass on my complaint, but I saw a pig preparing a flight plan and I doubt they will.

Just to repeat what I said before, Calor and Gaz are the SAME company in the UK and fill both Gaz and Calor bottles at the same depots with the same gas. A 6lb 907 Gaz cylider costs £17.40 and yet a 10lb Calor one costs £13.70. Our 4 907 refills cost therefore nearly £70, the same weight of gas in Calor bottles would have been around £33 - a huge difference.

I don't like being ripped off and especially when the quality control is apparently pretty well non-existent, at least from the filling plant that supplies The Calor Centre in Poole from where all our cylinders at our club come from.

[/rant.continued.]
 
I'm not sure what the inside of the regulators look like. Is it possible that liquid is getting in during fitting or replacing in the locker?
Also, is there some way to vent the excess into an empty cylinder? That way you would benefit from getting more gas than you have paid for.
Allan
 
The original bottle mounted regulators both had on/off valves that were of course 'off' when changing cylinders, but in any case I was careful not to tip the bottle when fitting them. As for venting the excess into another cylinder it isn't an option nor would it be worthwhile let alone safe. The excess is let off by sticking a small screwdriver into the ball valve where the regulator screws in and letting the gas off for 4 or 5 secs, occasionally it needs a second go. If it were caused by liquid getting into the regulator it would still not work surely after venting some gas off and trying again.
 
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Never happened to me. The only problem I've had is when a distributor has put red collars on empty bottles.

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That would be very annoying!

As I said before I've used gas on board a variety of boats for 35 years and the number of incidents has been very small, maybe just 4 times all told over 20 years, prior to that I only used Calor alone. The thing that made it a bigger deal is that it happened 2 years running and each time with multiple Gaz cylinders (4 each time) as we stocked up prior to a summer 5/6 week cruise. In between these 2 occasions we had several other Gaz cylinders that were fine and Calor bottles have always been OK until the one last weekend which was a different problem anyway.

Also The Calor Centre admit that it happens and seem unconcerned about it although they did understand my point that sorting it out (maybe taking 2 or 3 attempts) at sea was not quite so easy as doing it in a caravan park or marina berth.
 
On my gaslow you need to be gentle turning it on after any longish period. The leak protection seems to kick in quite readily if you just turn the tap to full in one.

A gentle twist, just so the indicator goes green and then slowly turn to full. Once there is gas in the pipe at pressure you can turn it on and off all day to your hearts content.

Should you have turned it on too fast, the cure is to turn it off, and lift the bottle a few inches, then the technical bit, bang it back down, repeat until safety valve resets. This is how I am awoken in the mornings, not by a hot coffee, but by the clunk clunk clunk as she has forgotten the trick of opening the valve slowly.

To be honest, it is not such a bad thing, it is as annoying as the smoke detectors going off when you forget to cover them or close the kitchen door at home when using the grill, it at least confirms that the safety feature is still working.

I think the problem is the length of the gas run on the boat, on a caravan or under the table in a tent it is only a few feet. We have a pipe run of probably 16ft, that is a lot of pipe to fill and hence a large pressure change when the pipe is empty. [/supposition]

<span class="small">p.s. asda are selling miniature smoke alarms that come in two parts, a clamp that you screw to the ceiling and the detector. On the boat this means you can just take it down when cooking with a quick twist, replacing when done. They are about 1/4 the size of standard detectors, using penny cells. Just thought I would give a heads up as they are ideal for the saloon. Packs of 2. No connection etc etc.</span>
 
I have the same problem as Robin except I have a Plastimo Neptune Cooker.

New cylinders always give me grief - they settle down after about 1/2 an hour of use as does my wife !

I have trouble keeping all 4 sectors alight, then of course the flame failure device cuts in and the whole thing stops.

In some ways this is good because the flame failure devices get tested but it does delay that nice hot cuppa !

Its only in the last few years I've noticed the problem. I fitted new regulator which made no difference.
 
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On my gaslow you need to be gentle turning it on after any longish period. The leak protection seems to kick in quite readily if you just turn the tap to full in one.


[/ QUOTE ]

I think we both have different Gaslow systems, but also the problems we have had with the Gaz cylinders all arose before we fitted the Gaslow. The Gaz cylinder at the time was connected by a regulator that screwed directly onto the bottle, initially the one that came with the boat and then a new one that I changed to after having problems.

The Gaslow changeover system we have just installed is this one where the on/off is done at each cylinder, either with the usual Calor screwdown valve or if using Gaz on one side via a screw on Calor/Gaz adapter with it's own on/off valve.

1645.gif


The Gaslow setup works fine and allows you to switch easily between two bottles, just open the valve on the new one and close the one on the old one. The problem we had last weekend with a new Calor cylinder was not the same, it wasn't over pressure there was just no gas coming through, suggesting either the cylinder was empty or was nearly so and cold temperature affected it. However the other Calor cylinder worked fine even though it wasn't full and also the duff cylinder check-weighed as being full, neither should have been affected by cold at 8 degsC outside (probably more in the gas locker). I now have another full Calor refill supplied FOC so will see what that does this weekend, I suspect there may have been something in the valve that didn't clear itself when connected but did when disconnected and opened up to test at the Calor shop. This I think was a one-off as I've never had problems with Calor bottles before, only with Gaz.

Again, because it seems that some people think the Gaz problem is at our end and not caused by overfilled cylinders, I will say that after each Gaz cylinder had some gas vented off by a screwdriver in the top ball valve for just a few seconds (or occasionally done twice) they worked perfectly all the way to empty on both the original and the new regulators. Also others at our club have had the same problems (with same source of cylinders) AND The Calor Centre admit it sometimes happens.
 
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I have the same problem as Robin except I have a Plastimo Neptune Cooker.

New cylinders always give me grief - they settle down after about 1/2 an hour of use as does my wife !

I have trouble keeping all 4 sectors alight, then of course the flame failure device cuts in and the whole thing stops.

In some ways this is good because the flame failure devices get tested but it does delay that nice hot cuppa !

Its only in the last few years I've noticed the problem. I fitted new regulator which made no difference.

[/ QUOTE ]

Finally some independent confirmation! I wonder if the cylinders come from the same filling depot that supplies Poole?

Anyway now you know that the 'solution' is to vent off some gas and reconnect, just don't do it where the gas can get below.
 
Robin,
On a charter boat we probably get through more cylinders per year than most and never experienced your problem.

Can I suggest that when it happens next you take the cylinder to anothr boat and see if that cooker lights.

If it does then process of elimination between your regulator or cooker.

You are a sensitive soul and I think your cooker/regulator is reflecting this!!
 
My suspicion is that it may be a gas quality issue rather than a simple over pressure issue. It would be very difficult to over pressure a gas bottle as the internal pressure is simply a function of the temeprature, and not how full it is, unless, there is absolutely no gas volume left. This will be next to impossible to achieve.

I suspect that there may be a contaminant gas in the bottles, probably nitrogen, which will preferentially fill the gas volume in the bottle. In some cases bulk supplied LNG/LPG will have other gases in it, which will "gas" out of the bulk liquid. If you get a supply of this into your bottle, the nitrogen in the top of a new bottle will mess up the stoichiometry of your flame, essentailly reducing the flame speed and producing the behaviour you describe. Venting the gas of the top of the bottle will draw off most of the nitrogen build up and restore the composition to normal.
 
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