Leaking shut off valve.

[Jonzjob]

I had a problem the other day where the motor protection CB for the pool pump and solar control tripped. It was a lovely sunny day and I was allerted to it because I couldn't hear the pump running as I passed the pool house. When I reset it the solar control panel regestered 125ºC onn the panel and when the pump came on water shot everywhere because the union nuts on the stopcocks either side of the heat exchanger has loosened. This has happened once before, a very long time back, and there were no problems after I had retightened the unions.

The 3 stopcocks are arranged thus. 1 before the heat ex (call it 'A'), 1 after the heat ex (call it 'B') and one as a bypass. There is no problem with the bypass.

This time the leak is still there, but it seems very strange and I think I am going to have to replace the stopcocks? Hopefully with identical ones so that I don't have to do a MAJOR plumbing job[:(]

What is happening is that when everything is tightened up, hand tight + a tiny bit, and the 2 either side of the heat ex are closed there are no leaks.

If I open 'A' there is a slight leak from it but not from 'B'. There is now pressure on both sides of 'B' so it can't be leaking from either flange.

If I now open 'B' it leaks like a sieve! Even if I just crack 'B' open a tiny bit!

I have removed and stripped 'B', removed the ball and inspected and throughly cleaned everything, including the seal on the adjusting ring. Everything was coated in silicon grease and reassembled. It still leaks and I believe that the leak is getting through the internal seal as soon as the ball is not sat completely on the neoprene seal around it and water can get into the main body of the stopcock.

A photo of the setup may help? Any ideas anyone please!!![+o(]

[IMG]http://i47.photobucket.com/albums/f180/Jonzjob/Johns/IMG_4798.jpg[/IMG]

[Théière]

By the look of it valve B is different to the others so this one due to temperature of the water must have been changed already for a similar problem?

Swop it out again for reliabilities sake, fortunately the difference in valve bodies is very little so it makes changing much easier.

[Jonzjob]

Ta for the info TP. They were all fitted at the same time by me when I

put the solar heating in. I have no idea as to why 'B' is different?

I went to the place that I got 'B' from and they still have the same

make BUT would you believe that the threads are different!!! How sick is

that. I think that the clowns who 'made' them had just bought a job lot

and badged them. Next job lot different threads!

I think that I have solved the problem though. I have been out this morning and bought all  of the fittings and am changing the lot from the horizontal pipes up! I could chase me bum all round Carcassonne and not find what I need so this seems the obvious way..

When I'm done I'll let the glue cure overnight before seeing how many other leaks I now have![8-)]

Thanks again[:D]

[Anton Redman]

Self annealling tape / auto vulcan.. worked for me

http://www.mocap-france.com/ruban-autoamalgamant-xtrem.html

[Jonzjob]

I doubt it would do any good on this one Anton because the leak is inside the valve. It's all been cut out now and partly replaced. I will finish it this afternoon after lunch..

Ta for the idea though..

[Jonzjob]

Problem fixed. 3 new stopcocks, 3 elbows, 2 'T's and an inline fitted. Didn't even need a drink after. With the smell of that plastic glue it could well have been 'high as a kite land'!!

Left the glue to cure overnight and switched it on this morning. NO leaks[8-|][8-|][8-|][B]

I even have a neater layout now. Well, I think so anyway[:D]

[IMG]http://i47.photobucket.com/albums/f180/Jonzjob/IMG_4801.jpg[/IMG]