Newly fitted isolation valve keeps leaking

[zenonithus]

Hi all,

I fitted some new isolation valves on my bathroom sink pipes in order to screw in my new basin tap flexi-hoses.

Hot water one is fine, though been having trouble with the cold one. It seems to pool over time in the olive/nut area shown in the picture. I tried several olives after a few attempts to redo it and even ptfe taped the olive. Seems dry for a while, then I go back to it and it has pooled up in this area a little, so it's a small slow leak but very annoying.

I did fit a new 15mm copper pipe (connected to the previous isolation valve) so not sure if that has anything to do with it? The hot water fitting was to the original older pipe.

Any suggestions as to what to do next? The ptfe tape around the olive was about the only solution I could find. Could it be something up with the valve?

 

[ShaunCorbs]

Are you overtighting it ? Should be approx 1/2 a turn of the nut

It’s not condensation is it due to the cold incoming mains ?

 

[Gasmk1]

Is it leaking from the isolation screw itself rather than the nut

 

[Chuck]

From the photo, it looks as through the casting of the isolator valve is poor quality so there may be a void or fissure causing the leak. Replace it with a decent quality branded one, e.g. Pegler. Follow the manufacturer's instructions for tightening when installing.

 

[RBG]

It also looks like (and it may just be my eyes lol) that the fitting isn't "square" onto the pipe. Looks a bit wonky to me

 

[zenonithus]

Are you overtighting it ? Should be approx 1/2 a turn of the nut

It’s not condensation is it due to the cold incoming mains ?

I may be over tightening it as I did read copper olives don't need tightening. I think it just leaked when I tried it just over half but I will try it less next time.

Is it leaking from the isolation screw itself rather than the nut

You know I was thinking that. I'll check the screw with a tissue

From the photo, it looks as through the casting of the isolator valve is poor quality so there may be a void or fissure causing the leak. Replace it with a decent quality branded one, e.g. Pegler. Follow the manufacturer's instructions for tightening when installing.

It's a little rough casted yes, could be a faulty one as the other is identical and works fine. If I still cant fix it I may well need to get another

It also looks like (and it may just be my eyes lol) that the fitting isn't "square" onto the pipe. Looks a bit wonky to me

Yes it does look that way from the pic, though it is definitly flush to the pipe otherwise it would be leaking loads.

I thought it could be collected condensation as its the cold pipe, but it feels like the water pools in the nut too quickly for that. Ok thanks for your replies, I'll have another crack at it tomorrow and see if I get anywhere 🙂

 

[MikeJhn]

I think it's indicative that more threads are showing on the bottom nut than the top, did you use the correct olive on the bottom of the isolation valve, way forward is to change the fitting with the respective correct olive's, will be difficult if you have necked the copper pipe by over tightening, but not impossible if the taps are on flexible's.