Straight service valve to toilet cistern: replacing with 150mm flexible hose

[MM]

The cistern service valve is very slightly weeping and so will have to be replaced. But in order to remove the valve I shall have to cut off the ferrule at the compression joint end. As it is unfeasible to actually saw through the ferrule, the usual approach is to saw through the pipe just past the ferrule. But then the gap between the cistern inlet and the new service valve is likely to be too large.

So what about fitting a 150mm flexible hose instead? There are several available, on eBay, on Amazon etc. These have a compression joint at one end and the usual coupling at the other end to screw onto the cistern inlet. They are available with or without an integral isolation valve. I would only choose the latter kind.

I've fitted compression joints successfully before, but have never used the flexible hoses for anything, so have no experience with them.

But surely the compression joint end is just like any other compression joint? Should just be the case of using a pipe cutter to cut the existing copper pipe, then fitting the hose? The only complication is that the builder painted the copper pipe white to match the bathroom! But paint stripper should remove it. Plus wirewool perhaps.

I assume one would attach the hose to the cistern inlet first, in order to gauge the right distance to cut the copper pipe for the compression end?

Am I on the right track here?

Thanks.

MM

[Fredxx]

Ferrule? Do you mean olive?

It is normal to simply connect the new onto the old pipe with the old olive, or if using a fibre washer, same nut with a new fibre washer.

After seeing a flexible hose fail I tend to avoid them with the exception of taps.

Or stainless steel scourer.

I'm wondering why you can't make a more direct replacement.

[newshound]

I am a big fan of using flexible hoses for things like this, only I would get one with an isolation (also known as service) valve. This is exactly what I just did when I had to replace a cistern recently.

I find the best way to deal with painted pipes is to scratch the paint off with a stanley knife blade, held perpendicular to the pipe and slid axially so that you take off longitudinal strips. When you have most of it off, finish off with steel wool. You don't want to make deep gouges in the copper, but superficial scratches are OK especially when finished off with wire wool. The point about olives is that they deform, and deform the pipe, when done up tightly, which is why they are tolerant of surface roughness and pipe tolerances. The female threaded end should come with a rubber washer to make the seal on the ball valve inlet.

And yes, whether using flexible or solid pipe, fit the pipe to the cistern first and then "cut and shut" to the existing copper.

[MM]

Yes. But I've seen it called ferrule elsewhere.

I thought one wasn't supposed to use the same olive again? Will it seal ok? If so, then I don't need a hose connection.

After what you said above I will probably attempt it.

MM

[MM]

Thanks. I've seen the short hose with integral isolation valve for around £3.50 on eBay or Amazon, but my local DIY merchant may actually have one on the shelf. I note your comments about scratching the paint off, but do you not rate paint stripper? Or is it corrosive on copper?

MM

[Harry Bloomfield, Esq.]

MM has brought this to us :

It will seal absolutely fine, if in doubt - wipe some Plumbers Mait around the olive.

[Harry Bloomfield, Esq.]

newshound wrote on 20/05/2021 :

Fibre!

[Harry Bloomfield, Esq.]

MM used his keyboard to write :

No need for stipper, just scrape it with a blade then finish with wire wool/ emery cloth or similar.

[Fredxx]

Unless it was leaking around the olive then it should be fine. There is no issue in reusing an olive if it's not being moved. If it looks good then best well left alone.

I have used one of these where the olive must be removed because of thread or other differences:

I would replace direct, and then check afterwards. Least effort and least disturbance.

[MM]

Good to know. I think I've still got a tin of that stuff somewhere, but it might have dried out by now. No worries, I'll get a new tin.

MM

[MM]

My goodness, people think of everything!

Yep. But I may just get me a 150mm hose connection as a fall-back if it goes pear-shaped. It's ony £3.50 and if I don't need it I can give it away on Freegle.

MM

[Harry Bloomfield, Esq.]

on 20/05/2021, MM supposed :

It should be fine, it's none setting and keeps a very long time.

[alan_m]

Do you mean the olive?

If so put a ajustable spanner behind it and hit the spanner with a hammer to gradually knock it up the pipe until it falls off the end.

I have done just that.

Think about not using the flexi with integral valve. The valve cannot be used if in future the flexi fails and needs to be replaced.

I also found that fitting the flexi to a vertical pipe is not idea. I found that fitting a 90 degree bend to the pipe from my floor and a short horizontal pipe before the flexi allowed the excess flexi to be routed a lot easier with bends that don't stress the flexi.

[newshound]

It's just fiddly to do on an in-situ pipe. The modern stuff is not quite as quick as old fashioned Nitromors too.

[newshound]

Might be, but rubber will work fine if it is a plastic valve (just like dishwasher or washing machine). Only a problem if it is overtightened.

[Brian Gaff (Sofa]

When you say flexible, is it one of those with a plastic overlay and is really bendy, or those terrible convoluted ones with ribs down them that are more bendable but not very strong. I fitted one of the latter to my hot tap in the kitchen and a little while later it got a pin hole in it and I had to get the more expensive nice pliable ones. It was the slight flexing of the sink that did the damage. In a loo setting, I guess one needs to be sure its in a place where it won't get knocked about by cleaners and the like. What about the aesthetics though, flexible does tend to look a little odd. Brian

[Roger Hayter]

If the joint has previously been waterproof it is much better to use the old olive (assuming it is a modern fitting and has the same thread as the new one) than to try to put a new olive on the same pipe. They usually seem to work well in the new fitting, and you can always use your sealant of choice, *on the distal end of the olive* not the thread, (PTFE tape and Fernox LX have worked for me) if necessary or for reassurance.

[MM]

It would look like this:

MM

[MM]

Turned out that a new fibre washer was all that was needed. I bought a packet of 10 for about 50 pence from local DIY store. I'm going to keep checking it all afternoon, but so far no drip after an hour.

MM

[Fredxx]

The beauty of fibre washers is they swell. One good reason to replace them if the joint is disturbed.

If it's not leaking now it probably won't in the future too.