old and new nuts

malvo · Posted: Tue May 22, 2007 4:34 pm Post Subject: old and new nuts

Hi, Ive just fitted a new cistern inlet valve, but the nut from the old pipe (connecting the water pipe to the new one, under the cistern)will not seal completely, perhaps it\\\'s imperial and new metric. How do I solve this problem please?

chr15 · Posted: Tue May 22, 2007 4:42 pm Post Subject: Re: old and new nuts

malvo wrote:

Hi, Ive just fitted a new cistern inlet valve, but the nut from the old pipe (connecting the water pipe to the new one, under the cistern)will not seal completely, perhaps it\\\'s imperial and new metric. How do I solve this problem please?

Make sure the fibre washer is in good condition-if not change it-failing that fit a flexi pipe which would mean cutting the pipe below the cistern and fitting the flexi connector-you can get a pushfit or compression for the copper pipe end.

malvo · Posted: Wed May 23, 2007 3:49 pm Post Subject:

Thanks, problem is really between the plastic screw pipe coming from the bottom of the inlet valve joing to the metal water pipe (small U bend), the nut is metal, it does not seem to make a complete seal, is there a sealing compound on something such?

Breesey · Posted: Wed May 23, 2007 5:20 pm Post Subject:

malvo wrote:

Thanks, problem is really between the plastic screw pipe coming from the bottom of the inlet valve joing to the metal water pipe (small U bend), the nut is metal, it does not seem to make a complete seal, is there a sealing compound on something such?

The threads should be the same. Make sure you aren't getting the nut cross threaded on the inlet, if you are it won't seal; and you could b*****r it beyond use. Also ensure your fibre washer is in good nick (ie use a new one).

malvo · Posted: Thu May 24, 2007 7:39 am Post Subject:

sounds as if my problem is this fibre washer, I don't have one, where should it be?

chr15 · Posted: Thu May 24, 2007 7:48 am Post Subject:

malvo wrote:

sounds as if my problem is this fibre washer, I don't have one, where should it be?

It sits on the end of the fitting where your brass swivel nut connects to your plastic valve inlet--if the nut cross threads you won't get it to seal properly so make sure the nut goes on dead straight-and if threads get chewed up and you can't get it to connect straight then you'll be wanting a new valve..

dal5band · Posted: Thu May 24, 2007 2:51 pm Post Subject:

The point where the water is sealed off is the where the washer is - the nut just presses and holds the joint together but the threads do not seal.

An old trick is to wrap some ptfe tape around over the washer if you can pull the nut back out of the way - it seals any weak points.

malvo · Posted: Tue May 29, 2007 7:48 am Post Subject:

I've wrapped a little and then a lot of tape around the screw but to no avail, less of a leak but still there. Not cross threading and as tight as i can go.

dal5band · Posted: Tue May 29, 2007 7:59 am Post Subject:

Did you pull the joint apart and wrap the tape around over the washer ? (wrapping around the screw threads is not the place). Do not over tighten - you will damage the screw threads on the plastic and need a new valve.

malvo · Posted: Tue May 29, 2007 8:30 am Post Subject:

don't have a washer!

dal5band · Posted: Tue May 29, 2007 8:56 am Post Subject:

is the connector something like this :

http://www.screwfix.com/app/sfd/cat/pro.jsp?id=92656&ts=28655

See the black bit inside the nut, that's the washer. The washer may be black rubber or red fibre stuff.

malvo · Posted: Tue May 29, 2007 8:59 am Post Subject:

yep although a more rounded top, can't remove the nut.

dal5band · Posted: Tue May 29, 2007 10:58 am Post Subject:

you can move the nut a little way along and get at the washer - fit new washer. Buy the washer first - "1/2 inch tap connector washer "

or as someone suggested cut the pipe and put in a flexi-connector.

TicklyT · Posted: Tue May 29, 2007 11:45 am Post Subject:

The nut is captive on the fitting, so it can't be removed. The washer sits over the spigot on the end of the copper pipe inside the fitting.
I would recommend replacing the washer any time the connector gets disturbed - they only cost a few pennies each.

After use they can get squeezed out of shape and wedge in the threads of the nut, and need digging out with a small screwdriver or similar. Sometimes they just fall out when the joint is dismantled.

These washers seem to be photophobic recluses - Drop one on the floor, and it immediatly makes off for the darkest remote corner it can find

You are trying to make a seal between the end of the threaded part of the ball valve and the flat area around the central spigot in the connector, not seal the nut to the thread of the connector.
The end of the ball valve spigot should be smooth and free of any nicks and dings or chewed bits of plastic that may be left from previous attempts.

Soak a new fibre washer in water for a while to soften it, clean any remains of the old washer out of the connector, push the new washer over the spigot in the connector and re-assemble. There should be no need for any PTFE tape or any other sealants. The nut should run up the threads easily by hand, and just need a tweak with a spanner to compress the washer. If it binds, check the threads are not 'crossed'

If the thread or end of the ball valve looks like something the dog has been chewing for a week, then you may need another ball valve

__________________
If it isn't broken, keep fixing it until it is

malvo · Posted: Wed May 30, 2007 7:43 am Post Subject:

SUCCESS FOLKS, many thanks to all for their advice, I have no drips, the washer was a success. I am no longer flushed with embarrassment.
Particular thanks to TicklyT also for your sense of humour, tickled mine.
Thanks again all