Gas bubble leak tester - should I bother?

[Maree]

I have a US imported boat - currently has a permanent guage on the regulator which can be used to check for leaks (gas on, pressure stabalise, gas off wait for reading to change).
We need a new gas locker, and as the existing set up is unlikely to pass muster at the survey due next year we've decided to go for a complete new gas pipe from cooker to cylinder. The corgi bloke says that the bubble leak testers can be unreliable in a marine/salt environment (and with two 25mm vents required it really will be a salty environment), and says not to bother - he'll test when he's installed, and it should be OK after that.

What do you guys use to test your gas - or is it a case of 'fit and forget'? Seems a bit alien to me.....

I do have sniffers by the way.

 

[prescott56]

Dunno, how reliable they are, but i fitted one and find it usefull as a quick and easy check that no gas is leaking.
also fitted a gas alarm.
for the cost i would fit both again.

regards
roy

 

[doug748]

Had no trouble with my leak tester, fitted about eight years ago. I find it very useful for a regular check. Mind you I don't have the two vents...

 

[TiggerToo]

Funny you shodul write this: my surveyor recommended a bubble tester. The CORGI guy I had to draft in was against it. I am also confused.

 

[doug748]

Is it too cynical to suggest that with the bubble tester you can test the thing yourself; thus cutting out the middle man?

 

[Dave99]

Gas Check Marine do free check but I think they only operate on the south coast

 

[Malcb]

I use a Gaslow 2004 Range - 500 Butane Regulator Gauge which I think is what your boat is fitted with, or something similar. When I visit boat, turn on gas bottle to pressurise, turn off gas. Do other boat checks, then check that the gauge still shows green, no leaks /forums/images/graemlins/smile.gif It also tells me how much gas is in the bottle, well roughly it does.

 

[VicS]

Although i have no personal experience of bubble testers it would seem to be sensible to include one as that then tests the syetem for leaks eveytime the gas is turned on, rather sooner than a gas alarm would respond! I have no recollection of any suggestions on the forum that they are unreliable in a marine environment.

You might be interested in reading what the Boat Safety Scheme says about gas installations see Section 7 HERE The more you know the less chance there is of some corgi pulling any wool over your eyes!
The testing of the syetem should include two parts. Firstly the LP system, excluding the regulator, is pressurised with air to 70mbar (thats above the normal working pressure) Then the whole system is tested using gas at 20mb for butane or 30 mb for butane. In both tests there should be no discernable pressure loss, measured with a U tube manometer, in 5 minutes.

 

[whipper_snapper]

I fitted one to my last boat and found it very helpful and very reassuring. And it did once detect a very slow leak.

 

[Hardley]

I've found the Bubble Leak Tester very good and would not be without one.
I take my cooker out of the boat each winter for cleaning, when I put it back I tighten the connecting nuts, but often the Bubble leak Tester tells me that I have not tightened them up enough, but the leak is not enough to set the Sniffer off.

 

[Miker]

I had a gas leak that the bubble tester did not show. It turned out to be the outward connection of the bubble tester itself. I detected the gas in the gas cylinder box by use of a hand held tester, and located the leak itself by a gas leak spray on all the connections. I am not arguing against fitting one, only beware of Sods Law.

 

[Dipper]

I've also just fitted a bubbler and gas monitoring system (alarm and solenoid) along with new copper pipe. The bubbler only checks downstream of itself. The solenoid and new regulator are upstream so it doesn't check for leaks in this area. I will get the whole system checked by an ex-Corgi friend.

I can see why a Corgi engineer may say a bubbler is not necessary. My new regulator has a test point on it for the professionals to check the system for leaks which if used makes the bubbler redundant. Of course, the owner won't have the expertise or equipment to do this and the bubbler does allow a check to be made every time the owner goes on board. In todays legal climate, it also shows that the owner has shown due diligence in the unfortunate event of a gas leak or explosion.

 

[Maree]

Thanks for all the replies - the consensus seems to be what I was hoping for(!) that it's worthwhile to be able to test on a regular basis. Having got used to doing the pressure test, I was certainly concerned about not having any control over the testing.

Dipper raises a good point about due diligence which I hadn't considered.

I'm planning to have my existing solenoid plumbed in - I like being able to switch off the gas in the locker whilst standing in the galley.
/forums/images/graemlins/smile.gif

 

[whiteoaks7]

I looked at bubble testers and was amazed at the price. The cooker I'd bought had a gas test nipple but this had not been bored through (my post of a few weeks ago) so a bubble tester seemed a good idea. However, I wondered if they would show a slow seepage - which would still fill the bilge over time. So I bored through the test nipple and used the standard U tube manometer to test the installation - no drop over an hour so must be good. I have also fitted a gas alarm (home made using RS calibrated sensors and Maplin/Velleman kits) which I test with a whiff of a gas match every time I use the boat. I feel the alarm is more use than a bubble tester ever would be (pm if you want details).

Note that if you use the U tube you need to pressurise the line then turn the gas back off at the bottle - so many people leave it on!!!! The watch for a decrease in the pressure over time. None of the gas men I've spoken too seem to have a figure for what's acceptable (and I used to work for the gas council) so I look for no leaks over 30 minutes minimum - but don;t quote me.

Cheers - Dave

 

[VicS]

[ QUOTE ]
Note that if you use the U tube you need to pressurise the line then turn the gas back off at the bottle - so many people leave it on!!!! The watch for a decrease in the pressure over time. None of the gas men I've spoken too seem to have a figure for what's acceptable (and I used to work for the gas council) so I look for no leaks over 30 minutes minimum - but don;t quote me

[/ QUOTE ]
Read my earlier post which very briefly summarises the tests, but to add a little more detail to the second one. The cylinder valve is opened to pressurise the systm and then closed. A little of the gas is vented to allow the presure to drop to the values I have given. The pressure then must remain with no discernable fall for 5mins.

The reason for venting a little gas is prevent the pressure being maintained during the test by the reservoir of gas that would otherwise be trappped at bottle pressure upstream of the regulator. The 5 minute period does seem remarkably short, but that is all that is required for testing systems on boats and caravans.

What a pity none of the gas men you know have bothered to read the relevant section of the Corgi manual.