Service valves, advice needed?

Ive just fitted a new toilet and basin, and ive put in service valves in-case i change tapes at a later date, at the end of the copper pipe i cut of the end and cleaned it up with wire wool, then put on the locking nut and then the olive and then tightened it all up, but there's a slight bit of wetness under the locking nut, its not a drip, but when i touch the pipe there's a little water on the top of the pipe, im not sure how much more i should tighten the nut up.


any tips or advice.Service valves, advice needed?
first i would check that the pipe has been cut square with a pipe cutter not hacksaw and the fitting is pushed as far as it can go.





in the past i have put a bit of PTFE tape on the olive a few rounds and tightened it and it solves the problem.





check the joint above the pipe sometimes the leak above might be the source of the leak.





if for some reason you overtighten it will leak but its not a major issue to undo cut the pipe and replace with a new olive and few rounds of ptfe tape on the olive





tighten slowly check dry it with a tissue or cloth and check again after few minutes if its still leaking tighten a bit more





http://www.ukcopperboard.co.uk/literatur鈥?/a>





follow the advice aboveService valves, advice needed?
Hello Andrew G.


Barry B. Has steered you right especially with the use of Boss White smeared on the olive to seal and lubricate.


After this you only have to nip the nut up onto the olive.


However be careful.


On the basin 9 times out of 10 if the moisture is on the top of the valve then the leak is above it, on the tap connector %26amp; running down the pipe.


On the toilet cistern it could be the same or even condensation running down the pipe. ( cold water coming into a warm room when the toilet is flushed ).


Finally, over tightening a compression joint will make it leak just as much as not tightening it at all.


BB.
A rough guide is hand tight then half to three quarters of a turn. If the pipe was undamaged, cut square and fully inserted into a fitting it shouldn't leak at all. Just tighten it a little more. If it just weeps it may settle in and/or seal with lime anyway. The only othe way is to use some 'Boss White' on the olive as this assists bedding in and sealing when tightening. Also if you cleaned it with wire wool along the tube rather than round it you may have created mini grooves which can bypass the olive.
Just tighten slowly a part turn at a time until the drip/leak stops...





I take it you have used compression joints -





Failing that, if that does not stop the leak - you may need to remove the compression joint and put a new olive in - you can also use something called Plumbers Mait - spread a little in the joint and tighten - it dries solid and seals small leaks
A little dampness is normal once tightened up. It is after you dry it off very thorough and re check for leaks. If it appears to be leaking the olive could have debris on it or worst case be defective. Oh. the cut on the copper needs to be a nice even round cut too.With this being said be careful not to over tighten the nut. Snug is the word.