tiny leak around union nut on new tap

[wrathkeg]

Hi all,

Fitted new bath/shower mixer yesterday. Despite putting PTFE tape round it, and tightening the nut as much as I dare, this morning I notice there is still a tiny drop of water seeping out at the top of the union nut. It's not running down the pipe or anything (but I do think it's sitting there laughing at me). Any views as to what I should do? Seems to me the options are

1. leave it alone and see if it gets better/worse

2. take the nut off, re-tape it, and connect it back up

3. cut back the copper pipe and fix e.g. a flexi hose so the connections are new (I am currently reusing the union nut on the copper pipe, which itself is sitting on a copper reducer to get from 22mm to 15mm (the pipework is all 15 mm). If this is the way to go, which kind of hose would I need?

Thanks in advance

wrathkeg

 

[Burnerman]

Use a new fibre washer on the tap connector together with some sealant (Jet blue or similar) and all will be well. You can use flexible connectors of course but expect a reduction in water flow....not ideal where a bath is installed!
John

 

[wrathkeg]

thanks for that, burnerman.

only issue is, there isn't currently a tap connector installed. at least, not this kind of thing:

http://www.wickes.co.uk/invt/194581

there is just a brass nut at the top of the copper pipe, connecting to the threads on the tap. would there be a washer in there, or just an olive? the nut won't slide back past the copper reducer, so there's no way I can look inside it.

 

[Burnerman]

If what you have is simply a 15mm copper pipe sticking into the brass base of the tap with only a compression nut on show, then there is an olive in there.
So, you'll have to remove or back off the pipe, some sealant and a couple of twists of ptfe tape around the olive only and pop it back together.
Sometimes access to drop the pipe down is pretty tight!
John

 

[wrathkeg]

that's the set up I have (copper pipe all the way to tap, and nut). I'll undo everything tonight and see if I can get some tape around the olive. thanks for the help.

wk

 

[Burnerman]

Always awkward to get a spanner up there....and the various wrenches available only work to a certain extent! Good luck with it.
John

 

[wrathkeg]

one more tiny thing. would regular sanitary sealant do, as well as the tape, or would that make it too much of a swine to remove later (i ask cos I already have that kind of sealant, but not the Jet Blue type)?

and i know about the restricted space-- I spent most of my Sunday afternoon down there.......

 

[Burnerman]

Believe me, I've used the silicone stuff before with no problems, but it isn't really kosher
One reasonable tip is to make sure the tap has a brass back nut and do it up tight when the pipe is off......if this is good and secure, there's much less chance of the tap twisting as you connect the compression nut.
Those plastic tap centralisers are good too, and I usually put a thin poly washer between the tap and the ceramic - this prevents the supplied rubber washer from squeezing out....but thats just my way!
John

 

[TicklyT]

Are your new mixer tails intended to accept a compression olive?

Most are intended for use with tap connectors. They have a flat or rounded end to seat against the fibre washer in a tap connector connector, and a parallel bore.

Compression fittings have a tapered bore to compress the olive as they are tightened. Likewise, the olive has tapered shoulders to seat in the fittings.

Put a compression olive into the end of a tap tail and at best you end up with a very narrow seating area around the olive, and virtually nothing compressing the olive onto the pipe.

Tap connectors with compression fittings at t'other end are commonly available to link copper pipe to tap tails. The variety of sizes available cater for most combinations of pipe and tap tails.

 

[wrathkeg]

thanks for this, tickly. to be honest, things ended up a bit tricky trying to reuse the existing connection at the end of the copper pipe, and i ended up not being able to move the nut one way or the other.....

So, I ended up cutting both pipes, putting on an isolation valve (none previously, though I wish there had been this weekend.....), and then a 15mm to 3/4 inch tap connector to the taps.

All *seems* to be fine now, though it's hard to tell whether there is a leak just yet as I had a bit of a flood in the course of doing this and the floorboards are still soaked

While I am sure that there will technically be a reduction in the flow due to the bore of the tap connectors, I must say: I can't really feel or see a difference.

one more thing: highly recommend this tool, small enough and sharp enough to cut neatly through pipes only an inch or so from the wall.

http://www.wickes.co.uk/mini-tube-cutter/invt/500529/

thanks all,

wk

 

[Charnwood]

Most are intended for use with tap connectors.

Actually, many manufacturers tap tails are chamferred to accept an olive. Pegler, Bristan and Deva are.