Gas leak

[Alan de Enfield]

21 minutes ago, Tracy D'arth said:

I don't understand the brass sleeve bit, especially if the pipe is loose in the sleeve. Its a BSS fail and I have never seen it done this way.

 

 

It would appear in fact to be a BSS requirement that it is done this sort of way ;

 

8.2 Is the LPG pipe protected where it passes through metal bulkheads or decks?  R

 

Check the protection of LPG pipes passing through metallic bulkheads or decks that can be seen or reached.

 

LPG pipes passing through metallic bulkheads or decks must be protected by the use of sleeves, grommets, or bulkhead fittings.

 

But I would have thought that using a 'brass' sleeve is not gaining much over going directly thru a steel bulkhead - although it doesn't say it, I'd have thought it means a 'rubbery' sort of sleeve or grommet.

Edited April 16, 2021 by Alan de Enfield

[plumbob]

I would concur with Patron that is the correct fitting drill through or cut, regs say the pipe should be secured within 500mm of a fitting, to stop vibration working the joint.

[blackrose]

1 hour ago, Loddon said:

I have always used proper gas bulkhead fittings drilled out so the pipe can pass straight through but tightened up as normal with olives etc. Possible overkill but not had one fail.

 

If you can cut the pipe at the bulkhead then you could just fit a proper gas bulkhead fitting, provided the hole in the pipe is in the correct place.

 

 

I fitted a bulkhead fitting on the gas locker bulkhead but that's a joint as I couldn't pass the pipe though in one. I didn't think of drilling a fitting out for the cabin bulkhead.

1 hour ago, Tracy D'arth said:

If the pipe is not cut, there is nothing to fail, best way.

 

I don't understand the brass sleeve bit, especially if the pipe is loose in the sleeve. Its a BSS fail and I have never seen it done this way.

 

The pipe is loose in the sleeve but goes right through the sleeve. There is no joint. It can't be a BSS fail if there's no joint.

Edited April 16, 2021 by blackrose

[blackrose]

1 hour ago, David Mack said:

So the answer to Blackrose's problem is to replace his existing sleeve with such a fitting, and with a bit of luck he will not need an intermediate joint or to replace the whole 12m length. As the fitting is designed to have separate pipes attached, no BSS inspector can claim this is an unnecessary joint.

 

But in my case I wouldn't drill the fitting because I have to cut the pipe and have a joint at the bulkhead? Or should I drill the fitting and slide it down the pipe and into place and just tighten it up on both sides assuming the chafed hole is in the middle and I'll be sealing it up?

 

1 hour ago, Alan de Enfield said:

But I would have thought that using a 'brass' sleeve is not gaining much over going directly thru a steel bulkhead - although it doesn't say it, I'd have thought it means a 'rubbery' sort of sleeve or grommet.

 

Well you might be right. I would have argued that a brass sleeve orientated in the same plane as the pipe and which protrudes on both sides of a 5mm steel plate bulkhead is less likely to chafe the pipe than the vertical steel plate which is on a 90 degree plane. However, given what seems to have occurred I guess I was wrong.

Edited April 16, 2021 by blackrose

[GUMPY]

1 hour ago, blackrose said:

But in my case I wouldn't drill the fitting because I have to cut the pipe and have a joint at the bulkhead? Or should I drill the fitting and slide it down the pipe and into place and just tighten it up on both sides assuming the chafed hole is in the middle and I'll be sealing it up?

I have drilled one out before and slid it along the pipe to get it into position, sometimes there is no other way. You will need to fix it into the bulkhead as well.

Just make sure the hole in the pipe is inside the fitting you may have to try the fitting both ways round to achieve that.

Edited April 16, 2021 by Loddon

[blackrose]

Thanks Julian and everyone else.

 

 

[plumbob]

I would concur with Patron that is the correct fitting, drill through breaks the regs as that is not how the manufacturer made it. regs say the pipe should be secured within 500mm of a fitting to stop vibration at the joint.

 

 

[blackrose]

Ok, sorry to waste everyone's time but I'm beginning to think that this electronic gas sniffer isn't such a great bit of kit after all.

 

I think I had the sensitivity set too high so although the buzzer was going off with the sensor near that bulkhead fitting, I didn't realise that it would also go off if I placed it in any random corner of the boat including up near the ceiling! 

 

I've calibrated it first in fresh air outside and then using my oven, letting out a bit of gas as it doesn't have auto ignition. When I go back to the bulkhead fitting I'm getting nothing on the sniffer.

 

I've checked every joint on the system using the same sensitivity setting and also the underside of the hob, the knobs, the top of the oven including joints and I'm getting nothing. Either the sensor sensitivity is too high and it goes off anywhere or too low and not at all.

 

I still have a leak showing on the bubble tester.

 

 

Edited April 16, 2021 by blackrose

[GUMPY]

20 minutes ago, blackrose said:

I still have a leak showing on the bubble tester.

Maybe the bubble tester is faulty

 

[blackrose]

6 minutes ago, Loddon said:

Maybe the bubble tester is faulty

 

 

I hope so! Perhaps I'll just buy a new one and fit it.

[Tracy D'arth]

I hate bubble testers! Now you know why!

[Tacet]

5 hours ago, David Mack said:

So the answer to Blackrose's problem is to replace his existing sleeve with such a fitting, and with a bit of luck he will not need an intermediate joint or to replace the whole 12m length. As the fitting is designed to have separate pipes attached, no BSS inspector can claim this is an unnecessary joint.

Good idea in principle but it might be tricky to thread the fitting from the end, as the pipe has probably been shaped.  And Blackrose might have fun passing the lock nut from the other end too.

[Ex Brummie]

If I understand the situation, then there is a brass sleeve through which the gas pipe passes. If so, then you might just as well let it pass through the cabin side. A loose pipe will chafe on brass as well as it will on steel. Whether the leak is there or not, it really should be rectified. The best way would be, if it is sound, to remove the brass sleeve and replace it with some close fitting rubber sleeve, clamped to the pipe so that it forms a grommet. However, given that you don't just have 5mm of steel to pass through, but insulation and internal panelling. As all joints should be visible for BSS,  a bulkhead fitting may not comply. I got over a similar problem after deciding to 'upsize' my gas pipe from 10mm to 15mm, by using a long brass nipple, held by locknuts inside and  out, with compression fittings at each end. The joints are visible both inside and outside.

Looking back through the thread, I can't see that you have sought to confirm a leak with a manometer. This would prove/disprove your bubble tester without having to spend another £50 on another bubble tester.

[ditchcrawler]

I am not surprised the bubbly leak fluid didn't show it up. You probably cant even see where the leak is coming out of the pipe and as its a sliding fit there is nothing to direct the gas though the liquid 

[blackrose]

1 hour ago, Tracy D'arth said:

I hate bubble testers! Now you know why!

 

Not really. Nothing lasts forever. That bubble tester is now 15 years old. If it's malfunctioned (and we don't know that yet) then it's had a reasonable innings and allowed me to test for leaks on a regular basis during that time.

 

What other peice of equipment would you recommend people who aren't gas engineers use to check their gas systems? 

19 minutes ago, Ex Brummie said:

 

Looking back through the thread, I can't see that you have sought to confirm a leak with a manometer. This would prove/disprove your bubble tester without having to spend another £50 on another bubble tester.

 

Ok. How much is a manometer?

7 minutes ago, ditchcrawler said:

I am not surprised the bubbly leak fluid didn't show it up. You probably cant even see where the leak is coming out of the pipe and as its a sliding fit there is nothing to direct the gas though the liquid 

 

And we're not actually sure there is a chafing leak.

[blackrose]

21 minutes ago, Ex Brummie said:

If I understand the situation, then there is a brass sleeve through which the gas pipe passes. If so, then you might just as well let it pass through the cabin side. A loose pipe will chafe on brass as well as it will on steel. Whether the leak is there or not, it really should be rectified. The best way would be, if it is sound, to remove the brass sleeve and replace it with some close fitting rubber sleeve, clamped to the pipe so that it forms a grommet. However, given that you don't just have 5mm of steel to pass through, but insulation and internal panelling. As all joints should be visible for BSS,  a bulkhead fitting may not comply. I got over a similar problem after deciding to 'upsize' my gas pipe from 10mm to 15mm, by using a long brass nipple, held by locknuts inside and  out, with compression fittings at each end. The joints are visible both inside and outside.

 

 

If it's not chafing and it's a faulty bubble tester then I'll ask the BSS inspector what he thinks of the brass sleeve next time he visits next year.

 

 

 

[Ex Brummie]

11 minutes ago, blackrose said:

 

 

 

Ok. How much is a manometer?

If you look back through the post, you will see how to make one, otherwise a 24" manometer. Otherwise, about £35 + vat, plus another £5 or so for manometer tube, from BES   https://www.bes.co.uk/flexible-manometer-24-60-mbar-water-gauge-20342/

 

[ditchcrawler]

22 minutes ago, blackrose said:

 

 

And we're not actually sure there is a chafing leak.

I thought you found a leak with your sniffer where it went through the bulkhead 

[Tracy D'arth]

6 minutes ago, Ex Brummie said:

If you look back through the post, you will see how to make one, otherwise a 24" manometer. Otherwise, about £35 + vat, plus another £5 or so for manometer tube, from BES   https://www.bes.co.uk/flexible-manometer-24-60-mbar-water-gauge-20342/

 

https://www.zoro.co.uk/shop/measuring-and-test-equipment/manometers/wm10-24"-manometer/p/ZT1017793X?utm_source=google&utm_campaign=pla%2B|%2BMeasuring %26 Test Equipment&utm_term=ZT1017793X&utm_medium=pla_css_2&targetid=pla-394793316945&loc_physical_ms=1006912&dev=c&gclid=Cj0KCQjw6-SDBhCMARIsAGbI7UisHcwdPaIO_VmspElwIUYuX23fGtWDVED8htwxbFukK40zGUsUlF4aAgNPEALw_wcB

 

£15.99  inc VAT.

 

or there are rentals.

 

Or make one.

Its only 4ft of clear plastic tube, clipped to a bit of wood and a bit of 8mm rubber tube to connect to the nipple. ( you do have a nipple don't you? )

1 minute ago, ditchcrawler said:

I thought you found a leak with your sniffer where it went through the bulkhead 

It seems that it was false reading on the gas sniffer, not unusual.

[ditchcrawler]

36 minutes ago, Tracy D'arth said:

 

It seems that it was false reading on the gas sniffer, not unusual.

That is why the ones we used cost 10 times as much. Dragar

[blackrose]

1 hour ago, Tracy D'arth said:

https://www.zoro.co.uk/shop/measuring-and-test-equipment/manometers/wm10-24"-manometer/p/ZT1017793X?utm_source=google&utm_campaign=pla%2B|%2BMeasuring %26 Test Equipment&utm_term=ZT1017793X&utm_medium=pla_css_2&targetid=pla-394793316945&loc_physical_ms=1006912&dev=c&gclid=Cj0KCQjw6-SDBhCMARIsAGbI7UisHcwdPaIO_VmspElwIUYuX23fGtWDVED8htwxbFukK40zGUsUlF4aAgNPEALw_wcB

 

£15.99  inc VAT.

 

or there are rentals.

 

Or make one.

Its only 4ft of clear plastic tube, clipped to a bit of wood and a bit of 8mm rubber tube to connect to the nipple. ( you do have a nipple don't you? )

It seems that it was false reading on the gas sniffer, not unusual.

 

Ok thanks. I'll buy one and watch a YouTube video on how to use it. My regulator has a test nipple.

 

I think the sniffer is reacting to an area of cut sprayfoam around the brass sleeve on the inside of the boat. I tried it on another area inside a cupboard where there's some sprayfoam showing and also on a piece of broken polystyrene packaging and it did the same thing. With the sensitivity set right on the edge that's what it does. At lower sensitivities/calibration it needs a bit more gas like my oven to set it off. So in short I'm not sure it's very good at detecting small leaks.

14 minutes ago, ditchcrawler said:

That is why the ones we used cost 10 times as much. Dragar

 

Yes probably.

So before I buy a cheap manometer, is that going to work, or is everyone going to say I need a more expensive one when it doesn't? To be honest I don't really want to see a reading on it. I want the bubble tester to be faulty.

Edited April 16, 2021 by blackrose

[Machpoint005]

8 hours ago, Loddon said:

I have always used proper gas bulkhead fittings drilled out so the pipe can pass straight through but tightened up as normal with olives etc. Possible overkill but not had one fail.

 

If you can cut the pipe at the bulkhead then you could just fit a proper gas bulkhead fitting, provided the hole in the pipe is in the correct place.

 

A snotty bss inspector could get arsey about the "unnecessary joint"

 

If the joint is there to prevent a failure due to chafing, it's not unnecessary! But I do agree with your sentiment.

[blackrose]

I don't think there is any chafing. I think that either there's a small leak I haven't found or the bubble tester is faulty. 

 

Edited April 16, 2021 by blackrose

[blackrose]

2 hours ago, Tracy D'arth said:

https://www.zoro.co.uk/shop/measuring-and-test-equipment/manometers/wm10-24"-manometer/p/ZT1017793X?utm_source=google&utm_campaign=pla%2B|%2BMeasuring %26 Test Equipment&utm_term=ZT1017793X&utm_medium=pla_css_2&targetid=pla-394793316945&loc_physical_ms=1006912&dev=c&gclid=Cj0KCQjw6-SDBhCMARIsAGbI7UisHcwdPaIO_VmspElwIUYuX23fGtWDVED8htwxbFukK40zGUsUlF4aAgNPEALw_wcB

 

£15.99  inc VAT.

 

or there are rentals.

 

Or make one.

Its only 4ft of clear plastic tube, clipped to a bit of wood and a bit of 8mm rubber tube to connect to the nipple. ( you do have a nipple don't you? )

It seems that it was false reading on the gas sniffer, not unusual.

 

Does anyone know what tube I need to buy?  I don't think you can buy any old 8mm tubing. Some of them say "not suitable for LPG". Why don't these things come with suitable tubes? It's like buying a bicycle without tyres and then you have to work out which ones will fit.

Edited April 16, 2021 by blackrose

[blackrose]

I'm sending the gas sniffer back to Amazon to pay for the manometer. If there is a small leak I don't think the cheap sniffer is very useful. 

 

What about a digital manometer? Can I use one of these? It's not much more expensive and much easier to store.

 

https://www.amazon.co.uk/dp/B078YDFX4R/ref=cm_sw_r_cp_apa_glc_fabc_BXJC2SQC3REA1CG8Z9YG?_encoding=UTF8&psc=1

 

Edited April 16, 2021 by blackrose