Gas Compression Fitting

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PhilipH

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So the gas on/off valve inside the boat is a bit dicky and full flow does not come when it is in line with the pipe - have to offset it slightly. Not happy so want to change. Got advice from Calor website on fitting one of these but it is not clear about replacing (http://calormarineshop.co.uk/boat_diy/compression_fitting.htm ). Having taken the old one off I find that the copper olives (brass is not recommended by Calor either) are, well, compressed on the pipe. The existing valve also has coupling nuts that are a different thread to the replacement valve coupling nut. So here's the question:

if I find another valve with the same thread as the existing one can I simply connect up with the in situ olive and coupling nut? Or, do I have to remove the existing olive because if I do it looks like I will have to cut the pipes or is there some CORGI secret method that allows the compressed olive to be removed.

If I have to cut the pipes I might as well fit the valve that I now have.

Help! and thanks for any advice.
 
Do not reuse the existing olive! Cut the pipe off as close to the olive as poss. and fit new complete valve.
 
I agree. It sounds as though the nuts on the existing valve have been overtightened.

Don't forget to leak test the new joints when done.
 
The olives are compressed onto the pipe because that is exactly what they are intended to do.......... you aren't meant to be able to remove them.

If you are able to get a replacement valve which has the same thread AND ALSO uses the same olives you can fit the replacement without cutting off existing nuts/olives. Unfortunately different manufacturers use several different olive types just to be unhelpful to us consumers...... nothing new there then!

To try and be slightly more helpful:
If you are aware of the correct "full-bore" position of the valve and it doesn't leak in that position then why change it.

I assume you are referring to the gas tap usually mounted just below the cooker. Personally I always leave this in the open position and just turn the gas on/off at the bottle in the cockpit locker.


Hope this helps,
Paul.
 
Yes the olive must come off. This willl enable you to fit the correct olive and nut. I would try removing the olive by filing or sawing through the olive. There is however a good chance you will damage the pipe itself and so have to cut the pipe back anyway. If you can get the olive off and the pipe looks smooth then use it. good luck olewill
 
SECRET METHOD!

Get a pair of toothed grips, do not squeeze tight otherwise you could disfigure the tube. Just tight enought to grip the olive. Twist forwards and backwards to loosen it and then start sliding the olive off the pipe whilst still shifting it forwards and backwards. They usually take about 5-10 seconds to remove.
 
You probably should do the "soundness test" in which the system is pressurised with air to 70 mb but to do that you need the wherewithall to pressurise it and a test point to connect a manometer. You could just test with the gas supply in which you burn off a little gas to lower the pressure to 20 mb (butane) but again you need a test point for the manometer. For either to be legally valid you need to be Gorgi registered of course! /forums/images/graemlins/wink.gif

At least do the soapy water test although the gas people have got you by the short and curlies again by saying that you should use a non corrosive leak detecting fluid! /forums/images/graemlins/wink.gif /forums/images/graemlins/wink.gif

I know what I would do. I'd use a few drops of washing up liquid in some water and rinse it away afterwards. Perhaps shower gel instead of the w'up liquid would be non corrosive. Having a keen sense of smell I would also use that!

If you have a leak detector in the system that'll confirm every thing is OK.

You'll find all the details of the tests on the Westerly O A forum where Philip Stevens has kindly posted them

BTW BES are much cheaper for gas fittings than calor shops
 
[ QUOTE ]
"non-corrosive leak detection fluid" is techno-speak for something very ordinary, but what

[/ QUOTE ] They want you to buy the sprays! I don't think soapy water is a particularly good choice unless you use soft water eg rain water, distilled water or water from a Brita Filter even then perhaps not that good. It is always said that washing up liquid contains salt thereby making it corrosive but I'm not so sure about that, however that is why I thought maybe shower gel or shampoo might be OK.
 
[ QUOTE ]
It is always said that washing up liquid contains salt thereby making it corrosive but I'm not so sure about that

[/ QUOTE ]

Oh come now, I tested all my joints with fairy and so far I am not left with mushed pipes in the bottom of the gas locker. If a little salt is a big problem, maybe we really should not use copper pipe on board. In fact any metal, in fact any material, it all rots or blisters, oh dear, I am going to buy a caravan.

Sometimes the perfection on PBO gets a little scary!
 
How do you clean the boat then ? remove all gas pipes first ? what about copper diesel pipes ?

When an apprentice I spent 6 months in engineering, went with fitter to the canteen to look into smell of gas, fitter used lighted match test to check for leak.

Brian
 
Well for the sake of using one product instead of another why not reduce the risks - I'm going with the shower gel.

Also, we really shouldn't knock people for offering good advice otherwise they may stop - I am grateful to VicS for his input.
 
Dog watch and halcyon,
[ QUOTE ]
test all joints with non-corrosive leak detection fluid.

[/ QUOTE ] is extracted from the Corgi Handbook.

It is not something I have made up or something PBO is being scary about and no where did I even imply that it was advice from PBO so on this occassion you can leave them out of it!
I don't believe a bit of w'up liquid is going to reduce the whole lot to mush any more than you do. If salt was the problem then copper pipe would be totally unsuitable on a boat any way. Some time ago I did test some w'up liquid for salt and found none so I believe the salt bit may be a myth anyway.

I merely repeated what the Corgi Bible says. I thought I had made it obvious that I did not believe it was necessary

As for testing for gas leaks with a match I hope any apprentice who sees that walks away for his own safety and reports the matter to his superviser, manager, or safety officer as approrpiate. It is highly irresponsible to even suggest it.

PhilipH,

Thanks for your support. I suppose I should know by now that whatever you say on here someone will challenge it.


Moonfire,

I think I said that somewhere.
 
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