replacing rigid gas pipe

[Jeff J]

It's just a normal hob & grill the taps used to turn the gas on & off for each burner are the same as isolation valves aren't they?
In my personal experience leak detection fluid has not been successful, but I have had no problem using a u-tube gauge. I agree with you about unqualified people not doing it, but in our area it appeared that no gas safe engineers could be ar*ed to do the small alteration I wanted doing on mine, so I had no alternative than to do some some research & do it myself & I think the original poster might have had a similar problem.

[lloydy]

no, the knobs to turn the gas on for the burner are not isolation valves, neither is the push button on your fridge. An isolation valve is a fitting fitted directly on the gas inlet to the appliance and enables the appliance to be isolated and removed/serviced without turning the complete gas supply off. All the knob on the front does is stop gas coming out the burner. This is nothing personal, just general comment but this is where a little knowledge can be dangerous as there is big difference between the two.
Also can't really comment on how you found leak detection fluid not to work, i use it maybe 30 times a day on disturbed joints and test points while servicing boilers. it does what its meant to.

To be honest, as a proper paid job i wouldn't bother with taking on install work on a camper. Its not worth my time, better money can be earned elsewhere in a shorter time. Obviously helping friends is a different matter.

Glad you sorted your own one out though, its a good feeling when you fix your own van

[Oldiebut goodie]

Calor used to have a very good website, sadly no longer up, which detailed how to fit appliances in boats. They stated that compression fittings were to be used throughout, no gunk on joints and copper olives to be used. I have had joints leak using brass olives but never with the copper ones. Calor never once mentioned using corgi, as it was, registered fitters/engineers in fact the whole site was geared to diy. ( it was http://www.calormarinegas.co.uk" onclick="window.open(this.href);return false;)
It is far more vital to have good joints in a boat as lpg vapours sink to the bottom of a boat and cannot drain out as in a van, following their guidance I have never since had a joint leak upon 1st making.
It is a funny sight watching someone bailing out a boat that has had a gas leak though! It looks as though they are doing nothing but miming the action.

[lloydy]

yep, I've done the bailing out on a narrow boat. You don't half feel stupid

[Jeff J]

Lloydy, thanks for the info.the hob does have one isolation valve in the gas line to it but I thought it better to test up to the taps on the hob so I regarded them as being the same thing. After fitting a compression joint I could detect a slight smell of gas but spraying fluid on the joints did not produce any bubbles.I think the leak was so small that it ran off the fitting before it had chance to indicate a leak. As oldie but goodie suggest it was a brass olive that was causing the problem( I'm not sure if I had overtightened it or undertightend it) but I could easily confirm there was a slight leak using the U tube. Replacing the compression fitting again cured the problem, which incidentally also had a brass olive but for what ever reason did not leak the second time.

[lloydy]

A drop test inc the appliances is fine, the isolation valves you have a probably a little manifold with a couple ISO valves on them? There is no point testing with them closed as there is often as much pipe work after them as there is before. Again though, they aren't really appliance isolation valves as they are not right on the appliance.
The use of a brass olive is not right, even if it's now not leaking. They are a harder material than the copper pipe and when tightened they deform the pipe rather than deform themselves.
If your using a brush on leak fluid, then you need to give the bottle a good shake so it foams up. You then apply it with the brush as a foam, it doesn't run off then.

[Jeff J]

So should I be replacing the 2 new compression joints that I used. There has been no smell of gas for over 2 years now but I would rather be safe than sorry. Yes you guessed right I had a double manifold which I wanted to change for a triple one, this necessitated adding a couple of elbows to the system one of which leaked after installation. I used ptfe tape on them do you think that is also a no no,as people seem to disagree on that one too.

[lloydy]

Ideal world they should be copper, your choice if you replace them. I wouldn't fit brass ones.
Personally I don't have an issue with jointing compounds or ptfe if used right. I would not use ptfe on lpg, would rather a smear of rated joining compound or nothing at all. Where exactly did you put the ptfe? On the olive or the thread of the compression joint?

[Jeff J]

Around the threads of the elbows.

[lloydy]

Right ok.. The threads is not where a compression joints seals. Putting ptfe there does absolutely nothing other than making it harder to do the nut up. Find and hold a compression fitting in your hand, remove the nut and olive. Look at the end of the joint where the male threads are, on the very end on the INSIDE you will see a slight shamfer, this is where it seals. When the nut and olive are tightened the olive is forced against this part. So if you want to use ptfe (remember to use a gas rated one not the normal stuff) you would put one wrap around the olive while it's on the pipe, then tighten down. Jointing compound you would put a smear on the shamfer.

[Jeff J]

Thanks

[kevtherev]

Autosleepers fitted isolation valves as standard Lloyd.
I know scottbot has a sleeper.