What size is the thread on a bog cistern ball valve (traditional ball and arm type, plastic inlet) ? Is it 3/4 BSP same as a tap fitting ? Need to fly into B n Q or somewhere quick at lunchtime to pick a fitting up for emergency leak repair at aging mother's later today (got called out at 11:30 pm last night ... :-\ )
Arfa
Yes - same as a tap. I had problems getting a good seal with mine - the pipework is copper. So used some Fernox LSX.
This is a side entry valve that is fed from a vertical copper pipe, using a right-angled connector. It has all been painted for many years. It has just suddenly started dripping from the connector. I pulled a further pinch up on it, but no help. As the ball valve itself is plastic, I guess it's got to be some kind of corrosion in the connector. Casting around in my plumbing bits, I have just come across a short flexi with a right-angled 3/4 BSP (I think) on one end and a 15mm push fitting on the other. It came as one of a pair with a replacement shower pump, but I did not used them, as the original pipes were still ok, so I just screwed them straight onto the new pump. If this little flexi fits the ball valve inlet ok, then I guess it will be a quick way of doing the repair, although I might take advantage of having the water off, to fit a service valve in the line.
Arfa
I'm guessing you have a 'standard' angled tap connector on the end of the pipework. Has a reduced diameter 'shouldered' end which just fits inside the end of the valve pipework, but which should have a fibre washer over the end of the stub of the tap connector, IYSWIM.
Could just be that fibre washer.
Think the problem with me was the tap connector wasn't exactly square to the valve pipe. And being plastic you can't exert much clamping force to the washer. A rubber O ring might have sorted it. When I redecorated, I took the opportunity to add a service valve and flexible pipe Which has slowed down the filling of the cistern by quite a bit - despite being a full flow type.
On Mon, 15 Jun 2009 13:04:58 +0100, "Dave Plowman (News)" had this to say:
You can, of course get a right-angle connector with a built-in service valve. It might be worth fitting this if you have to replace the connector anyway and there isn't a SV to start with.
Pound to a pinch of poop its either the fibre washer or the tap connector is not dead inline with the plastic inlet.
Overcome both by using a flexible (which has a big rubber washer). Don't forget to remove the paint from the old pipe before you connect the pushfit or whatever.
The pipe fitting will be 1/2" BSP (whose OD happens to be about 3/4" - so often leads to confusion).[1]
The bit of the fitting which connects with the plastic end of the ball-valve has a step which holds a fibre washer. The leak is almost certainly caused by the failure of the fibre washer. Replacing that should fix it, without any new fittings.
Incidentally, I wouldn't use a push-fit fitting on a pipe which has been painted - you'll have a hell of a job cleaning the pipe up sufficiently for the push-fit to seal properly. Also, if the pipe is more than a few years old, it may well be 1/2" Imperial size rather than 15mm. There's only a very slight difference (with compression fittings, 1/2" and 15mm are virtually interchangeable) but getting a 1/2" pipe into a 15mm push-fit fitting can present a bit of a challenge.
[1] With imperial pipe fittings - and copper pipe - the nominal size represents the BORE, so the OD is somewhat larger. The thread on a 1/2" BSP fitting is about 3/4", and the OD of a 1/2" copper pipe is pretty close to 15mm. Metric tube sizes, on the other hand, refer to the OD!
Yus
Assuming it is in line enough to screw together a smear of LSX sorts things.
As it turned out, it was 1/2 BSP, standard tap connector, and it did have a fibre washer, but there was so much corosion around the connector, that I renewed it anyway, and took the opportunity to fit a service valve, as the cistern is fed from the loft tank, so pain in the arse to drain down. Then the probs started. Same as you Dave, it was really hard to get the connector to go on square due to the slight slope on the cistern face, so I struggled to pull it all up enough to get a good drip free seal. Eventually, I did exactly as you had thought about doing, and nipped down Wickes and picked up a packet of O rings for a quid. Put one on in front of the fibre washer and screwed up again, and lo! - it all stayed dry as a bone. Great minds think alike, as they say ... d;~}
Arfa
Yep - I wanted to fit a flexi, but even the shortest one would have been too long for the space I had, so would have had to have been seriously 'curled up'. I sorted it all in the end, and yes, the alignment of the valve and connector was an issue - see my other post replying to Dave P elsewhere in the thread.
Arfa
Yep. Got to the bottom of the sizes in the end, and got the job sorted. Thanks all for valuable input, as always.
Arfa
LS-X is the answer to a maidens prayer....
Wonderful stuff!
Yup. It's one of those things I don't mind paying a high price for because it works.
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