Leaky gas tank?

[Lenny HB]

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.

But unless you take the tank off how can they do a proper inspection?
There could be muck trapped above the tank causing corrosion most tanks are not fitted like you have done yours.

 

[CazPaul]

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.

I wonder why Germany dropped the gas test? Too difficult, not enough qualified people/companies around, not considered thorough enough to meet regulations etc ?

 

[jongood]

I wonder why Germany dropped the gas test? Too difficult, not enough qualified people/companies around, not considered thorough enough to meet regulations etc ?

I've been told by a fellow Clou liner owner, registered in Germany that a EU wide gas test was supposed to take its place but its not been agreed yet.

 

[John Russell]

Just to clarify, CG Gas did a leak test on the tank and connectors and a visual inspection. They couldn't do a pressure test.

Fwiw I had a good look at it when it was over a pit for its MoT - it's a 75L tank, mountings look good with plenty of clearance, and couldn't see any signs of damage either.

 

[jongood]

But unless you take the tank off how can they do a proper inspection?
There could be muck trapped above the tank causing corrosion most tanks are not fitted like you have done yours.

In the case of the Clou liners the side panel next to it hinges upwards so its quite easy to inspect. I take your point about some of these underslung PVC but surely no professional would agree that something they couldnt clearly see was ok and that would merit removal and testing or replacement.

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[JockandRita]

CG Gas in Peterborough have a good reputation and are long standing.

Very local to me John Russell, and it was Tori who checked over our underslung tank and gas system on the Hymer for security and leaks, and also certificated it to that effect.
He saved us a fortune from what was his opinion, "an unnecessary replacement".
Had we not managed with the 2 x Gaslow refillables we inherited with the Flair, as discussed with him, he would have been fitting an underslung tank for us

I'm glad he was able to sort you out in the end.

Cheers,

Jock.

 

[Basildog]

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.

Unfortunately whilst years ago a visual check and a guy who apparently has plenty of experience was considered by many to be good enough,I won’t take the risk for our company, staff or customers.
We are aware that the NCC has basically told all their approved workshop scheme members not to touch underslung LPG tanks at all .
We have been involved in producing a maintenance training course but this categorically states that it’s maintenance training only, it does not include installation and specifically excludes the 10 year maintenance / testing / valve replacement.
There is now a specific requirement for the tank to be removed in COP 32 .
There is not a single company in the U.K. that we are aware of that can or will carry out this recertification, so as a company the only sensible advice we can provide to our customers is replacement of the existing LPG tank .
Most 10 year old tanks would fail the corrosion inspection as the majority of owners have ignored the annual maintenance requirements.
We had one in not so long ago that was so badly corroded the owner had fibreglassed it up
At periods not exceeding 10 years from the date of installation the following shall be carried out:
Tank shall be removed from the vehicle ,stripped,subjected to a thorough examination (including a pressure test), and recertified by a competent person, if found to be satisfactory, it shall be stamped with test date of 10 year test undertaken and repainted.
The valves and regulator shall be renewed.
The hoses shall be renewed.
After re-assembly and re-installation, the installation shall be tested and recertified by a competent person.
When a tank is moved from one vehicle to another it is recommended that the opportunity is taken to carry out a thorough examination and recertification.

I should also add that anyone that operates an LPG pump is responsible legally to ensure that the installation is in certification and in good condition, as the pump operators are legally deemed to be the filler , self service operators might have a defence but as we operate an attendant service we don’t
For a few pence profit on LPG just not worth it.

 

[The Wino]

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.

I asked about a slow leak on our gasit cylinder on the filler. It can happen the shut off valve in the cylinder only operates when there's a significant leak ( happy to be torn to shreds if wrong!). The new filler sounds like a bodge to me especially if they had to glue it to get a seal

 

[Basildog]

Very local to me John Russell, and it was Tori who checked over our underslung tank and gas system on the Hymer for security and leaks, and also certificated it to that effect.
He saved us a fortune from what was his opinion, "an unnecessary replacement".
Had we not managed with the 2 x Gaslow refillables we inherited with the Flair, as discussed with him, he would have been fitting an underslung tank for us

I'm glad he was able to sort you out in the end.

Cheers,

Jock.

30 years ago that approach was perfectly acceptable for most industries and exactly what our fitter has done hundreds of times over the years.
He won’t put himself or the company in a position where we haven’t explicitly stated the current situation , there are now plenty of Codes of practices and relevant regulations, standards, manufacturers recommendations etc now .
Anyone who chooses to ignore them in a professional capacity is taking totally unnecessary risks.
We even have insurance against us as directors being prosecuted for negligence etc whether directly caused by us , the staff etc .
We give out what we know is the responsible advice , what customers then choose to do is up to them , there are plenty of LPG businesses out there run by people from other countries who will happily sell anything for any purpose and have absolutely no idea about the existence of any codes of practice, probably don’t have a single leisure industry gas qualification either.

 

[Basildog]

I asked about a slow leak on our gasit cylinder on the filler. It can happen the shut off valve in the cylinder only operates when there's a significant leak ( happy to be torn to shreds if wrong!). The new filler sounds like a bodge to me especially if they had to glue it to get a seal

Not that common to get a leak on the filler and as said there are 2 non return valves, normally the problem is not having a filler cap in place so dirt / debris can and does lead to both valves sticking open .
Another problem can be old pump hoses where they allow what looks like black worms to again hold the valves open .
Worst case scenario is a major liquid state LPG leak on a garage forecourt, we have a customer who will never use his local LPG pump again as they police cordoned off the road and fire brigade was in attendance for the duration

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[DuxDeluxe]

Unfortunately whilst years ago a visual check and a guy who apparently has plenty of experience was considered by many to be good enough,I won’t take the risk for our company, staff or customers.
We are aware that the NCC has basically told all their approved workshop scheme members not to touch underslung LPG tanks at all .
We have been involved in producing a maintenance training course but this categorically states that it’s maintenance training only, it does not include installation and specifically excludes the 10 year maintenance / testing / valve replacement.
There is now a specific requirement for the tank to be removed in COP 32 .
There is not a single company in the U.K. that we are aware of that can or will carry out this recertification, so as a company the only sensible advice we can provide to our customers is replacement of the existing LPG tank .
Most 10 year old tanks would fail the corrosion inspection as the majority of owners have ignored the annual maintenance requirements.
We had one in not so long ago that was so badly corroded the owner had fibreglassed it up
At periods not exceeding 10 years from the date of installation the following shall be carried out:
Tank shall be removed from the vehicle ,stripped,subjected to a thorough examination (including a pressure test), and recertified by a competent person, if found to be satisfactory, it shall be stamped with test date of 10 year test undertaken and repainted.
The valves and regulator shall be renewed.
The hoses shall be renewed.
After re-assembly and re-installation, the installation shall be tested and recertified by a competent person.
When a tank is moved from one vehicle to another it is recommended that the opportunity is taken to carry out a thorough examination and recertification.

I should also add that anyone that operates an LPG pump is responsible legally to ensure that the installation is in certification and in good condition, as the pump operators are legally deemed to be the filler , self service operators might have a defence but as we operate an attendant service we don’t
For a few pence profit on LPG just not worth it.

After our meeting on Friday afternoon and your inspection, I will be replacing the tank in the autumn although still technically in test as a bit less than 10 years old. Thanks for the very good advice

 

[jongood]

Not that common to get a leak on the filler and as said there are 2 non return valves, normally the problem is not having a filler cap in place so dirt / debris can and does lead to both valves sticking open .
Another problem can be old pump hoses where they allow what looks like black worms to again hold the valves open .
Worst case scenario is a major liquid state LPG leak on a garage forecourt, we have a customer who will never use his local LPG pump again as they police cordoned off the road and fire brigade was in attendance for the duration

no disrespect to anyone, but surely there would have been warning signs before it got to that stage, that a responsible owner would have picked up and taken it to a company to have it rectified or replaced, as indeed the OP did.

 

[Basildog]

But unless you take the tank off how can they do a proper inspection?
There could be muck trapped above the tank causing corrosion most tanks are not fitted like you have done yours.

There’s no point in trying to explain it to some people, they will just go to a different fitter / company until they hear what they want .
Personally I know it’s not correct and hasn’t been subjected to the recommended testing and inspection, it hasn’t even had the most important valve changed (PRV)
I have also shown the picture to our fitter who has around 40 years experience and just as I thought he believes that the take off valve is either modified or incorrect.

 

[ChrisL]

In my days (many years ago) welding in the petrochem industry, pressure testing of vessels would be done by filling the vessels with water and pumping them up to usually twice the working pressure, they were held at pressure for a period to check for leaks and also the circumference was measured to check for deformation, if the working and test pressure are known I don't see why an engineering company that does petrochem work couldn’t do that for you, certainly ones that I have worked for would have done, look for companies that advertise non destructive testing. Cost wise ofcourse it might be better to replace but it doesn't hurt to enquire. It would ofcourse be better if their was an industry standard procedure for this but whilst there isn't this may be a solution. On a slightly different note scuba tanks are inspected and tested regularly and test dates are stamped on the bottle.

 

[Basildog]

In my days (many years ago) welding in the petrochem industry, pressure testing of vessels would be done by filling the vessels with water and pumping them up to usually twice the working pressure, they were held at pressure for a period to check for leaks and also the circumference was measured to check for deformation, if the working and test pressure are known I don't see why an engineering company that does petrochem work couldn’t do that for you, certainly ones that I have worked for would have done, look for companies that advertise non destructive testing. Cost wise ofcourse it might be better to replace but it doesn't hurt to enquire. It would ofcourse be better if their was an industry standard procedure for this but whilst there isn't this may be a solution. On a slightly different note scuba tanks are inspected and tested regularly and test dates are stamped on the bottle.

We are currently looking into the possibility of testing but I am pretty certain that it’s completely economically unviable.
Time alone to remove the tank, remove the valves, strip the paint (no mechanical operations can be used ) carry out a corrosion inspection that most would fail .
Treat and repaint the tank that would technically have to go away for powder coating then revalve and test ?

So now does the customer want to pay for a failed test and a replacement tank ?
They are basically mass produced relatively cheap tanks , most customers understand this and accept that they require replacement at 10 years.

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[ChrisL]

So now does the customer want to pay for a failed test and a replacement tank ?

Interestingly scuba tanks that fail test have to be destroyed by the test centre so they don't have a choice. Scuba tanks are visually inspected every 2.5 years and pressure tested every 5 and these are legal requirements. LPG tanks work at much lower pressure though so testing wouldn't need to be that stringent.

 

[Basildog]

Interestingly scuba tanks that fail test have to be destroyed by the test centre so they don't have a choice. Scuba tanks are visually inspected every 2.5 years and pressure tested every 5 and these are legal requirements. LPG tanks work at much lower pressure though so testing wouldn't need to be that stringent.

I don’t think it’s financially viable to test them but can you imagine telling some people you have destroyed their tank
I love seeing the posts from the Leisure gas fitters bragging how they have capped off or disconnected a customer’s gas without any questions.
I am Gas Safe Registered and we cannot disconnect or cap off any gas supply or appliance without permission from the owner / responsible person.
All we can do is advise and then report to the gas supplier who does have the power / authority to disconnect a customer from their supply .

 

[Kannon Fodda]

Testing scuba tanks is more practical than an lpg underslung. For a start scuba is intended to be portable and there is only the valve itself to remove. Most scuba cylinders fail testing on the neck thread. It's something generally done at small scale, often in one or two man type workshop facilities, alongside other servicing of scuba kit.

Even the portable refillable lpg cylinders intended to replace or replicate calor type bottles would present an issue for testing. For a start, what size vessel is needed for any containment in case of failure during a pressure test when you have so many overall different capacity and shapes.

However, I suspect the testing bit alone would be economic for lpg cylinders, especially the bottle types, if there was a suitable facility. What makes it uneconomic is the cost of time to disassemble and later reassemble, and get it to that facility (what happens to the motorhome whilst the cylinders are away for the test). Many of the bottle type refillables are kept in lockers so probably aren't in as bad a condition, but underslungs probably mostly do have corrosion and related issues. I suspect even the bottle types would desire some internal cleaning adding to costs (not unusual for scuba cylinders to have internal shot blasting) If the associated pipework, regulators and such like also needs to be tested / checked, then chances are you are already half way towards the cost of replacement. In today's society when we should be looking to reuse rather than throw out that does seem wrong, but it's not always going to be practical to extend lifespans.

Bottom line we whinge, but accept, that things on our vans need replacement or preventative maintenance at certain service intervals. Timing belts being a prime example. Perhaps we need to accept lpg system also have a lifespan?

 

[ChrisL]

Testing scuba tanks is more practical than an lpg underslung. For a start scuba is intended to be portable and there is only the valve itself to remove. Most scuba cylinders fail testing on the neck thread. It's something generally done at small scale, often in one or two man type workshop facilities, alongside other servicing of scuba kit.

Even the portable refillable lpg cylinders intended to replace or replicate calor type bottles would present an issue for testing. For a start, what size vessel is needed for any containment in case of failure during a pressure test when you have so many overall different capacity and shapes.

However, I suspect the testing bit alone would be economic for lpg cylinders, especially the bottle types, if there was a suitable facility. What makes it uneconomic is the cost of time to disassemble and later reassemble, and get it to that facility (what happens to the motorhome whilst the cylinders are away for the test). Many of the bottle type refillables are kept in lockers so probably aren't in as bad a condition, but underslungs probably mostly do have corrosion and related issues. I suspect even the bottle types would desire some internal cleaning adding to costs (not unusual for scuba cylinders to have internal shot blasting) If the associated pipework, regulators and such like also needs to be tested / checked, then chances are you are already half way towards the cost of replacement. In today's society when we should be looking to reuse rather than throw out that does seem wrong, but it's not always going to be practical to extend lifespans.

Bottom line we whinge, but accept, that things on our vans need replacement or preventative maintenance at certain service intervals. Timing belts being a prime example. Perhaps we need to accept lpg system also have a lifespan?

Further to those excellent points, LPG tanks would also need to have residual gas reclaimed and be purged with nitrogen or other inert gas before testing adding further to the cost, the scuba example was just to show it could be done but as has been said it may not be financially viable.

 

[2GB Racing]

Scuba breathing air cylinders as stated are much much higher pressure and either alloy or mild steel welded construction, and usually refilled at a local dive store with a compressor and in a water tank to help remove the heat generated with the high pressure.
So are easy to have a visual inspection of the outside at every fill between required tests.
lpg mild steel tanks are basically a few pounds to fabricate run at a very low pressure so pretty thin steel and in an underslung situation in a hostile situation with stones, mud, and running aground always a risk so can not see an issue with replacement at 10 yrs as standard practice or immediately with a grounding issue.
To do the required testing would never never be viable remove from vehicle, transport to test station, test, refit, paperwork etc. Just weigh them in for scrap.
Bit tough on those with LPG in an on board locker as a less hostile environment etc.

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[CazPaul]

Testing scuba tanks is more practical than an lpg underslung. For a start scuba is intended to be portable and there is only the valve itself to remove. Most scuba cylinders fail testing on the neck thread. It's something generally done at small scale, often in one or two man type workshop facilities, alongside other servicing of scuba kit.

Even the portable refillable lpg cylinders intended to replace or replicate calor type bottles would present an issue for testing. For a start, what size vessel is needed for any containment in case of failure during a pressure test when you have so many overall different capacity and shapes.

However, I suspect the testing bit alone would be economic for lpg cylinders, especially the bottle types, if there was a suitable facility. What makes it uneconomic is the cost of time to disassemble and later reassemble, and get it to that facility (what happens to the motorhome whilst the cylinders are away for the test). Many of the bottle type refillables are kept in lockers so probably aren't in as bad a condition, but underslungs probably mostly do have corrosion and related issues. I suspect even the bottle types would desire some internal cleaning adding to costs (not unusual for scuba cylinders to have internal shot blasting) If the associated pipework, regulators and such like also needs to be tested / checked, then chances are you are already half way towards the cost of replacement. In today's society when we should be looking to reuse rather than throw out that does seem wrong, but it's not always going to be practical to extend lifespans.

Bottom line we whinge, but accept, that things on our vans need replacement or preventative maintenance at certain service intervals. Timing belts being a prime example. Perhaps we need to accept lpg system also have a lifespan?

The point is all these should be explained in full before sale/fitting which they certainly are not, only the benefits were explained.

 

[Basildog]

The point is all these should be explained in full before sale/fitting which they certainly are not, only the benefits were explained.

We actually do tend to explain to people that they can realistically expect to replace their tanks / cylinders in 10 years .
Do car dealers explain that a new car has a limited life expectancy, your household central heating boiler isn’t going to last 20 to 40 years like they used to , I personally wouldn’t repair one at 8 years old now .
Unless you buy a Miele domestic appliance they are all pretty much junk at 5 years today .
I doubt if Fiat actually expects a Ducato van to be still in service at 10 years.
Regulators , hoses and valves all need replacement at 10 years too according to manufacturer recommendations and the relevant standards.

 

[Odd job]

we can do is advise and then report to the gas supplier who does have the power / authority to disconnect a customer from their supply .

Not as easy with LPG as the supplier is not always known.
I have had several conversations with customers who didn't want their boiler shut off, telling them that I can only do it with their permission but if they refuse permission I can arrange to have the gas shut off by the gas emergency service. I never did need to call, although a few customers became aggressive but they all calmed down in the end.

 

[Lenny HB]

What is the pressure scuba tanks are filled at?
I know when filling from a pump LPG is around 140psi.

 

[ChrisL]

What is the pressure scuba tanks are filled at?
I know when filling from a pump LPG is around 140psi.

There are different pressure tanks but the average would be 200 bar.
Out of interest with a 15 ltr cylinder that would give you 3000 ltrs of air at the surface.

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[Lenny HB]

There are different pressure tanks but the average would be 200 bar

Blimey that's like having a bomb on your back.

 

[ChrisL]

Blimey that's like having a bomb on your back.

I haven't dived for a long time, my first cylinder pumped to 175 bar then I had a twin set that pumped to 200 bar, nowadays I think they may go as high as 240 bar but i'm not up to date on the latest spec.

 

[Basildog]

Not as easy with LPG as the supplier is not always known.
I have had several conversations with customers who didn't want their boiler shut off, telling them that I can only do it with their permission but if they refuse permission I can arrange to have the gas shut off by the gas emergency service. I never did need to call, although a few customers became aggressive but they all calmed down in the end.

Yes sorry I meant the main gas network not LPG .
I was just using the example that as you know we can’t disconnect any gas systems without specific permission.

 

[Kannon Fodda]

In resorts using aluminium scuba they tend to be about 200 bar (2900 psi). This also reflects that these cylinders can get some seriously heavy use. Steel cylinders are normally about 232 bar (3360 psi). I have seen some high pressure smaller steel scuba at 300 bar (4350 psi), but many stores wouldn't have compressors that could serve those.

Of course this pressure needs a lot of material. A standard 12litre cylinder can be 14Kg +. Put a pair of those on your back, filled you are over 30Kg, interesting for your back when being bounced around on a boat pre-dive. Gets worse when in a drysuit so you still need lead around your waist so you can sink, and many who are doing the deeper dives will have added cylinders hung under their arms to reduce the decompression stop time. No wonder I had frequent visitor tickets to the osteopath ....

Filling scuba tanks is a bit interesting, as you should ideally have a blast wall between the tank and operator, but that's rarely achievable, especially on liveaboard and similar environments. And if you are mixing gas (only the shallow dives are made on compressed air, go deeper and you try and reduce the nitrogen as that can cause narcosis - a feeling of drunkenness underwater - or even use a helium blend), usually adding pure oxygen first, the heat of the compression process increases the risk of ignition. I actually think the LPG, at lower pressure is probably a lot easier to handle.

 

[funflair]

lt all looks like a bit of a dogs dinner to me, the COP 32 seems to be a code of practice for gas installations in park homes as it keeps mentioning connected to external bottles and caravan sites for more than 4 weeks while connected to an external cylinder, and then right at the end it says to me that it is not applicable to vehicle tanks for non propulsion purposes and Liquid Gas UK code 11 applies, what is in that I am not sure yet as you have to pay for it,


FROM COP 32

Guidance is included on maintaining appliances and the installation pipework in a safe condition. It includes details of a standardised procedure and check report, which should be followed by a competent person to verify the safety of the gas installation. This includes checks on the appliances, gas tightness of the system, ventilation and flueing.

This includes leisure accommodation vehicles (LAVs) such as:
• Holiday caravans
• Touring caravans and trailer tents that are connected to an external LPG supply not incorporated in the original manufacturer’s design
• Touring caravans that are used for more than four weeks while connected to external cylinder supply
• Other vehicles with or without aftermarket conversion incorporating accommodation for habitation.

Code of Practice 32 does not cover the installation of tanks on vehicles for non-propulsion purposes. Where tanks are being installed in vehicles for non-propulsion purposes, the requirements for installing tanks and their fittings (including filling pipework and connector) are set out in Liquid Gas UK Code of Practice 11.

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