Finding a small gas leak

Magic_Sailor

Magic_Sailor

Well-Known Member
Joined
7 Dec 2002
Messages
2,552
Location
Marchwood
Visit site
I think I've got a tiny gas leak in the pots and pans locker beneath the cooker on the boat.

The pipe appears through a bulkhead and has a number of "nut and olive" connections for isolation taps and "branches".

I'm not too worried as it is so small but I would like to get to the bottom of it.

How can I check these joints for leaks?

Magic
 
no such thing as a small gas leak, it will collect in your bilges waiting for the day it can blow you and your boat to the great boatyard in the sky.

soapy water on the joints will show up a leak, if theyre compression fitting a gentle tightening will usual seal it. You can get aerosol leak detectors which you spray on the suspected joint, You could also open the leaking joint if tightening doesn't do it and use 'gastite' thread sealer.

good luck with your leak detection.
 
Yes, use a bubble solution. Best to get the proper stuff from a plumber merchant than use 'washing up liquid'

Although the cheap stuff can work the proper stuff has bubbles that stay together and will show smaller leaks than ordinary soap solution.

If you do use washing up liquid then make sure that you rinse everything with plenty of fresh water afterwards to wash away all of the salt that is in the stuff. I know it sounds silly on a boat but it can cause corrision of the pipework if you are not careful.
 
I agree any gas leak should be taken seriously.

If its a loose joint vibration might loosen it further. If it is the beginning of a crack in the pipe one day a bit of vibration might fracture the pipe completely. Far better to find it now than wait until it suddenly gets worse when it might find you with a bit of a bang! Ever see the pictures of the Lord Trenchard a few years ago?

Never tried one of the aerosols but a few drops of washing up liquid in some water works well (Don't use soap unless the water is soft eg distilled or rain water). It might also be a good excuse for buying a portable gas detector which will be handy if any of the joints are difficult to see.
 
[ QUOTE ]
all of the salt that is in the stuff.

[/ QUOTE ]
I've heard it said before that w'up liquid contained salt but when I tested some in the lab it didn't. Sensible to wash it away though.
 
Use a soapy water solution and a small brush.If you find the leak on one of your olive compression fittings dont put anything on the threads as these only pull the fitting together not making the seal.

Wrap a bit of ptfe tape around the olive and onto the pipe slightly then reassemble it .Dont overtighten it.Then carefully check for leaks again.

Testing for gas leaks with a flame is only recommended if you use safety matches /forums/images/graemlins/grin.gif
 
I agree about the threads but I'm not so sure about PTFE tape on the olive. If the leak is between the pipe and the olive that might not work anyway. Better to use a joining compound sparingly that might just penetrate betwen the two IMHO. There is one for LPG I think called Calortite. It is still not recommended see here:
http://www.calormarineshop.co.uk/boat_diy/compression_fitting.htm

Also I believe there is a special grade of tape for gas installations where its use is appropriate.
 
Any gas leak can be dangerous. LPG (butane and propane) is heavier than air and sinks in to the bilges. If it is a joint best to clean up and remake. Testing with wash up liquid works well though clean and rinse afterwards. I have used a jointing compound in the past such as hawk white ? that is ok for gas but compression joints should not require it.
 
M/Sailor

Call a reg gas fitter, He will test with a hand held electronic gas detector so no mess or fuss, leave it to him to repair or replace as necessary as he should have the correct fittings with him.
Though there`s nothing to stop you doing it yourself it`s not advisable.
And please DON’T check with a naked flame, you might start something you cant stop.

…………..
 
In theory an olive type compression fitting should be assembled dry with no further sealing neccessary.

In practice due to cheap imported fittings sometimes this doesnt work.

The Gas approved ptfe is 10 times thicker than normal stuff as it is only intended for use on threaded joints where the thread is the seal.

In practice two wraps of the normal thin stuff overlapping the olive onto the pipe at both ends will cure it.Or use a smear of Gastite ,calortite or suchlike in the same place.

check that the pipe protrudes out of the olive about 2 mm at the end.If the pipe doesnt protrude out of the olive ,possibly it slipped as the fitting was being tightened ,then dont try to reuse the pipe ,olive or the fitting
as it will have been distorted during tightening.
 
[ QUOTE ]
I would never trust my own DIY capabilities with something so dangerous.

[/ QUOTE ]

i agree with you Jim,it is dangerous stuff.In some areas it is impossible to get someone to work on a boat and if you can find someone the bill is likely to be horrendous .

All he is going to do is find the leak undoe the fitting and retighten it with a sealing agent ,tape or paste.

At the end of the day your nose will smell gas as well as anyones and your eyes will spot the bubbles coming through a bit of soap solution.
 
[ QUOTE ]
M/Sailor
Though there`s nothing to stop you doing it yourself it`s not advisable.


[/ QUOTE ]

How do you get on with the insurance angle? I'm not allowed to fiddle with gas, not even allowed to connect up the stove, theoretically. (Commercial vessel, MCA certificate)
If it came down to a claim and you had no cert from a Corgi installer, would the insurance company be awkward?
 
different rules for commercial vessels.

IIRC inland waterways impose other rules.

I was always taught to keep ptfe tape away from the olive, but a smear of calortite eitherside and on the threads was acceptable. I did my own system that way, and the pressure guage on my system (permanent installation) shows that it is fine.
 
As a registered gas fitter I hate to say this but the fact is at the moment there is no legislation to stop DIY on a gas installation on boats or caravans that are privately owned, used only for pleasure and do not need a boat safety certificate. Although it does make my blood run cold when I see advice dished out like p.t.f.e. on an olive, smell with your nose and use matches to test, unfortunately I can only recommend that any such work be done professionally.
However in the case of Industrial, domestic installations or caravans and boats that are hired out or used in a commercial environment as is yours any diy work is illegal.

On the insurance angle I can only give an opinion but I would think it`s pretty safe to say that following a gas related claim any loss adjuster would be looking to see who carried out the gas work.

……..
 
That remark is downright irresponsible.You have to use safety matches /forums/images/graemlins/mad.gif
 
Agree with Uncle Albert 100%.

Do not mess around with LPG, its heavier than air & will collect at the lowest point & go BANG... /forums/images/graemlins/shocked.gif

Check the age of your pipework & unless its a brand new installation, I would install all new kit. Test with air & a U tube or get a bubble leak tester in line.

Lots of info here /forums/images/graemlins/wink.gif

poter.
 
You must log in or register to reply here.

Share this page

Top