Leaky gas tank?

[John Russell]

We have a large underslung gas tank, factory fitted in 2001. I recently noticed that over four months, the fill level had reduced on the control panel from 20℅ to 10℅ whilst the tank was locked off.

The tank appears externally to be in good shape.

One niggling worry is that when we got the van it had an M10 to dish adaptor which we used on our return journey from Poland.

When we got home we took it to a motorhome repair shop for an MoT and to deal with a few issues.

I asked them what the thread on the adaptor was. For reasons best known to themselves, they fitted a UK filler and a set of adapters to attach to it without discussion. First they said they'd cut a matching thread, and when I asked about the thread, that they'd glued it in.

Whilst this is an awkward bodge, I'm wondering whether their approach might be connected to the apparent leak, and whether it's safe or good practice.

I'd like to get the installation checked out. Gas Safe have a register which includes local engineers, but I'm wondering where to find someone who's used to dealing with motorhomes in the Cambridgeshire-Suffolk-Peterborough area?

And any expert opinions on the setup?

 

[Abacist]

I tried a local gas safe engineer who had every qualification going but he didn’t feel qualified to check our MoHo over so get someone who knows what they are doing and can evidence relevant current experience!

 

[Jimbohorlicks]

You can check the bodge connection with a leak detector spray ,obtainable from screwfix or toolstation, to give you some peace of mind and an indication if you have a leak or not.

 

[MisterB]

You may find more LPG qualified people around seaside resorts than in towns or cities. Alternatively try to find a garage that undertakes LPG conversions for vehicle engines.

 

[MisterB]

You can check the bodge connection with a leak detector spray ,obtainable from screwfix or toolstation, to give you some peace of mind and an indication if you have a leak or not.

Great idea for an initial check but for peace if mind over a longer period I would then still find somewhere who will do the job to your satisfaction or check that it has been done correctly.

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[meanders]

CG Gas in Peterborough have a good reputation and are long standing. We have a guy in the next village who has had two cars converted by them. He doesn't know if they do leisure vehicles though. They may be able help/advise.

 

[Lenny HB]

2001! Tank should be tested and new valves fitted every 10 years, time for a new tank.

 

[Bessy765]

Given the age it needs either replacing on service thats quite old for a tank. The filller point is only used for filling the tank there is a non return valve in the actual tank itself to prevent back leakage. The isolator valve on the side of the tank only closes the supply. So you have a non return valve just inside the fill point and one in the tank so unlikely to fail. During the filling process the pressure from the pump forces both non return valves open and when the pressure drops a spring forces the closed. So if leaking from the fill side it would have to pass two valves. I would get some leak detector spray but given the adage of the tank service or replace. If not you may get into space before the space x from cornwall.

 

[John Russell]

Thanks for all the suggestions.

I may have a quick check with the leak detector spray, and see if I can spot a problem before I take it to a professional.

Can anyone recommend others in my area?

 

[John Russell]

2001! Tank should be tested and new valves fitted every 10 years, time for a new tank.

Lenny HB Good idea to change the valves if these are 20 years old, but when I get it tested, if the tank is in good shape, no reason to change that too afaik.

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[Bramidan]

MCE Herts are fitting a Gas it system for me next week. I’m not sure if they come out to your area but you might be able to arrange a half waypoint.
Check out their website for info.
They are good at answering the phone and replying to e mails.
If they cant help they might be able to suggest somebody nearer to you, worth a call.

 

[Lenny HB]

Lenny HB Good idea to change the valves if these are 20 years old, but when I get it tested, if the tank is in good shape, no reason to change that too afaik.

I don't think you can get tanks tested in the UK so probably a new tank and valves that old should be changed.

Basildog will know.

 

[Jev88]

Let someone like CGGas Peterborough take a look. Took him 30 seconds to find a leaking tank... You mention how old your LPG tanks are - unprotected they can rust and pinhole. Especially near any poorly fitted straps that hold the tank.

 

[John Russell]

Yes, all good points thanks - I will get it tested, CG Gas is handy, and if we do need a new tank it'll be an opportunity to upgrade it.

Any other suggestions welcome, maybe further afield, in case we need a new system.

 

[Mike800966]

Don't forget that the volume will change with temperature, that might be a reason for some of the change. But a 2001 is due a change
Mike

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[Basildog]

Interesting topic for me actually.
Not sure where to start but here goes , unfortunately there has been some very bad information about user owned refillable cylinders and tanks put out there by certain suppliers.
The basics are that any pressure vessel requires a test and replacement valves at 10 years no matter who owns it .
Now here comes the fun bit , the likes of Calor and Flogas can get an exemption to extend the lifespan of their cylinders to 15 years as they are inspected by them at every refill and valves changed if required.
The crazy bit now is that the NCC has actually told all their so called approved workshop members not to touch underslung tanks as they don’t have the necessary training, but you won’t find a Gas Safe Registered operative who has a clue about underslung tanks either
I have been involved along with others helping to approve a training course for NCC guys but don’t hold your breath as it’s already 20 years too late in my opinion.
Interestingly the industry trade bodies like Liquid Gas etc are now just realising that there are now thousands of user owned cylinders and tanks out there with no test
We are now starting to get serious when filling customers systems as the moment we start to fill a system we are liable for it and should have inspected it to ensure it’s within test and in good condition etc .
I will start another thread on this topic but the long and short of it is at 10 years all cylinders and underslung tanks require testing or replacements.

 

[John Russell]

Basildog Thanks for the explanation of the system.

So as well as testing the system, valves should automatically be replaced at 10 years, or can valves be tested/inspected and dealt with accordingly?

Presumably there's the shutoff valve and the one-way inlet valve to the tank.

 

[meanders]

Of course there have been many incidents where 11 year old tanks and fittings have caused serious issues! That said, while inspection and test on a regular basis makes an awful lot of sense, replacement of steel and brass items purely on age is, to anyone with an engineering background, overkill if there is no corrosion or damage.

 

[RandallC]

first off I'd get a very soapy solution of water and washing up liquid splash it around fittings and tank etc, and find the leak.

Secondly when found (fix or prevent leakage) wash off the soap solution as it contains lots of salt.

Thirdly you have to check what the regulations/recommendations are for tank/hose/equipment inspection/replacement and mange accordingly.(insurance get out if not done)

Always remember Propane is heavier than air and will find the lowest area to collect in, waiting for an ignition source (unless well ventilated)

Edit, Garage pits are one and any enclosed space. I.E an enclosed space could be your MH!!!!

 

[Odd job]

you won’t find a Gas Safe Registered operative who has a clue about underslung tanks

That is so true I had the ACS element for leisure accommodation vehicles there was nothing about underslung tanks

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[funflair]

Interesting topic for me actually.
Not sure where to start but here goes , unfortunately there has been some very bad information about user owned refillable cylinders and tanks put out there by certain suppliers.
The basics are that any pressure vessel requires a test and replacement valves at 10 years no matter who owns it .
Now here comes the fun bit , the likes of Calor and Flogas can get an exemption to extend the lifespan of their cylinders to 15 years as they are inspected by them at every refill and valves changed if required.
The crazy bit now is that the NCC has actually told all their so called approved workshop members not to touch underslung tanks as they don’t have the necessary training, but you won’t find a Gas Safe Registered operative who has a clue about underslung tanks either
I have been involved along with others helping to approve a training course for NCC guys but don’t hold your breath as it’s already 20 years too late in my opinion.
Interestingly the industry trade bodies like Liquid Gas etc are now just realising that there are now thousands of user owned cylinders and tanks out there with no test
We are now starting to get serious when filling customers systems as the moment we start to fill a system we are liable for it and should have inspected it to ensure it’s within test and in good condition etc .
I will start another thread on this topic but the long and short of it is at 10 years all cylinders and underslung tanks require testing or replacements.

That begs the question, how do you test a cylinder? in my chemical plant fitting days we would blank off all entry or exit pipes and then fill it with water and then put a pressure test on it, the test figure would be given to us by the registered "pressure vessel inspector".

 

[Basildog]

That begs the question, how do you test a cylinder? in my chemical plant fitting days we would blank off all entry or exit pipes and then fill it with water and then put a pressure test on it, the test figure would be given to us by the registered "pressure vessel inspector".

I can’t remember the exact standard but we have had one customer that works in the engineering department of the National Grid that did strip , shot blast powder coat , revalve and test his cylinder with Nitrogen to the required pressure.
His conclusion was it was a mistake and would just replace in future

 

[Basildog]

Of course there have been many incidents where 11 year old tanks and fittings have caused serious issues! That said, while inspection and test on a regular basis makes an awful lot of sense, replacement of steel and brass items purely on age is, to anyone with an engineering background, overkill if there is no corrosion or damage.

Luckily I am not an Engineer so tend to follow industry standards and technical advice.
But working with LPG every day and seeing more and more leaking underslung tanks and tanks that have fallen off the vehicle, what I know for certain is the importance of good maintenance.
I have seen plenty of rusty tanks that eventually go pourous and leak .
Pressure relief valves , take off valves and gauges alll require replacement @ 10 years as do most filler hoses and regulators.
Possibly the tanks and valves of 40 / 50 years ago were serviceable ,but today’s lightweight tanks and modern steel aren’t designed for refurbishment.
The rubber seals , diaphragms and non serviceable brass valves with nylon valve seat faces definitely need replacing.

 

[John Russell]

I visited CG Gas in Peterborough this morning and Tori checked the gas tank and connections. He pronounced it to be in good condition and no leaks.

Remarkably the control panel shows 30% full gas, compared to 0% in December. Tori suggested the December reading could have been caused by low temperatures.

He did a nice job of fitting an external fill point, removing three adaptors fitted to convert M10 to UK bayonet, and connecting the fill point to the tank.

I'd wondered how to handle any remaining gas in the tank before opening the inlet valve.

The answer was to burn it off, but luckily mine had a valve.

 

[Lenny HB]

Tori checked the gas tank and connections. He pronounced it to be in good condition and no leaks.

If he didn't do a pressure test on it there is no way of knowing its in good condition.

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[Basildog]

I visited CG Gas in Peterborough this morning and Tori checked the gas tank and connections. He pronounced it to be in good condition and no leaks.

Remarkably the control panel shows 30% full gas, compared to 0% in December. Tori suggested the December reading could have been caused by low temperatures.

He did a nice job of fitting an external fill point, removing three adaptors fitted to convert M10 to UK bayonet, and connecting the fill point to the tank.

I'd wondered how to handle any remaining gas in the tank before opening the inlet valve.View attachment 728675View attachment 728676 The answer was to burn it off, but luckily mine had a valve.

Whilst you are obviously now thinking that’s all sorted , unfortunately it’s not what all the current standards and codes of practice say .
I can stick my head under any van and say your tank looks In great condition.
To be honest with you I am am actually totally disillusioned with the current situation in the leisure industry.
It’s a complete joke , even the big names haven’t got a clue when it comes to technical issues regarding gas installations.
We actually had a van in the other day with over 30 gas leaks and the idiot owner said he had gone this far he couldn’t afford to do it properly

 

[Basildog]

If he didn't do a pressure test on it there is no way of knowing it’s in good condition.

I actually despair at the current state of the leisure industry.
I saw an idiot proposing that a camping gaz 907 cylinder was capable of providing gas in a van with a possible maximum off take at 10.85 kw
You would be lucky to get 3 kw out of a 907 .
Even a 7kg butane is only capable of producing around 5 kw and that’s providing the temperature is above 15° C

 

[CazPaul]

I actually despair at the current state of the leisure industry.
I saw an idiot proposing that a camping gaz 907 cylinder was capable of providing gas in a van with a possible maximum off take at 10.85 kw
You would be lucky to get 3 kw out of a 907 .
Even a 7kg butane is only capable of producing around 5 kw and that’s providing the temperature is above 15° C

So basically every underslung tank and refillable needs either proper pressure testing or dumping after 10 years?
But no one can realistically pressure test them in this country?

That needs to be on the front of yours and every website page that fits them, it needs to be the first thing you say to people when they enquire.

We had our underslung fitted by your company 4.5 years ago, no one said that to us. Not a mention of it needs replacing after 10 years, maybe it’s in the associated paperwork?

As long as it’s all up front beforehand then there can be no complaints.

 

[Lenny HB]

So basically every underslung tank and refillable needs either proper pressure testing or dumping after 10 years?
But no one can realistically pressure test them in this country?

Yep, our Alugas cylinders are dated 2013 bought them in March 2014, been in use 9 years so we will do a trip via Germany within the next 12 months and get them tested & referbed or exchanged, probably exchanged as it's only €20 more.

 

[jongood]

Whilst you are obviously now thinking that’s all sorted , unfortunately it’s not what all the current standards and codes of practice say .
I can stick my head under any van and say your tank looks In great condition.
To be honest with you I am am actually totally disillusioned with the current situation in the leisure industry.
It’s a complete joke , even the big names haven’t got a clue when it comes to technical issues regarding gas installations.
We actually had a van in the other day with over 30 gas leaks and the idiot owner said he had gone this far he couldn’t afford to do it properly

You do have my sympathies, people like that must be really frustrating and its pretty shocking that there is no legislation prevent it, this guy could be in a tunnel next to anyone of us.

What the OP has done seems entirely reasonable to me. In the absence of a formal test the tank has been inspected by a gas professional who presumably is satisfied that it isnt leaking and doesnt show any apparent signs of falling off.

I have a very similar setup that is almost certainly more than 10 years old that was put on decent brackets with a good coating of a stonechip paint and a big plate to protect it from stones and appears to be working perfectly. I treasure my mh, it would be very difficult to replace and I'm not averse to spending money on it, if there was a test then I would have it tested but I'm not about to have something replaced for no apparent reason for something likely to be inferior.

Interestingly, Germany used to have a gas test for leisure vehicles that was widely respected but they have now dropped it.

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