New Pipework and Tightness Test

[jaydebruyne]

So I overheard a conversation today at a plumb centre and I wanted to know if it was true or not - it doesn't seem feasible to me but I'm new so what the hell do I know! Lol

So the guy was saying, when you TT after you've amended or extended any domestic gas pipework, if the pipework is still hot the reading on the gauge will fluctuate. So the reading may say there's a drop when in fact there isn't.

In my head it's an excuse cos he prob gets leaks and justifies it to himself.

So before I thank badly of him, I wanted to check out the facts.... Is this true?? Do you get readings that fluctuate if the pipework is still warm? I thought that's what the stabilisation minute was for?

 

[Geyser]

Yes it will. Same effect as when the sun comes out and warms an external pipe, you can see the reading go up.

 

[jaydebruyne]

Yes it will. Same effect as when the sun comes out and warms an external pipe, you can see the reading go up.

So say you're doing internal work, is it best to wait til the pipe has cooled before you test? As he was saying he got a 1mbar drop but put it down the the pipe cooling...

 

[ShaunCorbs]

as above expansion of internal gas

 

[Scott_D]

You can make a digital gauge go up and down by putting your hand on the gas pipe.
Wait tils its cooled before testing

 

[jaydebruyne]

as above expansion of internal gas

Question on post #3?

 

[ShaunCorbs]

Question on post #3?

to no 2 you were to fast

and just purge before you test wont rise as much as if it was full of air, but still except some movement

 

[tamz]

As he was saying he got a 1mbar drop but put it down the the pipe cooling...

Well he shoulda tested it again