Plumbing fittings questions ?

[mseries]

I need some help from someone who is knowledgable about fitting taps. I am going to fit a new monobloc mixer tap and in order to make it relatively straightforward to connect to the existing pipework would like to use flexible tails from the tap. The pipes are regular 15mm copper. I intend to fit an isolator into both the hot and cold and then would like to screw the flexi tails to the isolator. What specification flexible tail do I need ? The tap is M12 thread, so is 12 x 15 x 300 what I need or is does this have a compression fitting to fit a 15mm pipe ?

What about 12 x 1/2"x300, is this the one to attach to the isolator ? The 1/2" BSP thread is confusing me, since it's clearly larger than 1/2" diameter. Does anyone know where I can get these ? Screwfix and Toolstation don't seem to list them.

thanks

 

[DiscoStu]

I'm no expert but have done this. I put a small piece of pipe from the isolator and then use the compression fittings on the tails to connect to that as that was the fittings I had. However there should be no reason why you can't screw directly onto the isolator valve if you've got the compression "nuts" on the end of the tails as opposed to the whole compression fitting (which would accept a pipe and be facing the wrong way)

These should be what you want:

If you're going to screw fix you can ask them if they'll fit directly onto your isolators but they should do.


Sent from my iPhone using Tapatalk

 

[Phil Pascoe]

You can get flexible tap tails with inbuilt isolators.

 

[mseries]

thanks Discostu, adding a short piece of copper did occur to me, I was hoping to minimise the number of joints by screwing the flexi tail to the isolator (2 versus 4 per pipe) and also save some space.

 

[mseries]

You can get (iirc) tap tails with inbuilt isolators.

Yes' I've see those but they won't be much use if I want to change the tap in the future as I'll have to remove the isolator too rather than just the tail and refit a new tail.

 

[Phil Pascoe]

Just change the tap.. Why remove the tail?

 

[mseries]

Just change the tap.. Why remove the tail?

because you can't unscrew the tails from monoblock taps while they are connected at the other end

 

[Wuffles]

1/2 inch flexi tail to the isolator with the olive and nut removed is what you want. Go to a store, get them both on the counter and you'll see.

 

[mseries]

It's the nomenclature that is alien to me, is 1/2" BSP the term for the thread that a compression fitting for 15mm pipe, say an isolator valve, has.

 

[mseries]

1/2 inch flexi tail to the isolator with the olive and nut removed is what you want. Go to a store, get them both on the counter and you'll see.

one of these http://www.notjusttaps.co.uk/spares-flexitails-12mm.htm ? or cheaper here http://www.stevensonplumbing.co.uk/12mm ... rs-fi.html

 

[Wuffles]

That's the spirit.

What did the taps come with, 12mm non-flexi? You can build something like lego from what toolstation or screwfix have in stock.

 

[Wuffles]

If they did, fit the non flexi to the tap, then add these to the ends of the 15mm pipe coming out of the taps and connect the other end to the isolator coming off your tails.

Cheaper, gives you more wiggle-room, and it's over the counter in case it's not quite right. Possibly cheaper at Toolstation, not sure what's nearer you, but you get the idea.

I have had, in the past, flexi tails that go into the tap not be quite as well constructed and leak at the tap end. Probably cheap rubbish, that's what I normally buy anyway.

 

[Eric The Viking]

I was hoping to minimise the number of joints by screwing the flexi tail to the isolator (2 versus 4 per pipe) and also save some space.

You have to be fairly careful with that (i.e. what Wuffles said first about joining straight to Conex): ordinary compression fittings (with olives), such as in-line service/isolating valves, can be the same thread as the flexi, but usually come to a too-narrow rim on the outside end of the thread.

The ends of the flexi-pipes DiscoStu showed are probably intended for fibre washers, and the male thread they connect to (on the isolating valve) needs a reasonably wide flat rim to give some area for the sealing washer to mate with. If it doesn't seal well you risk leaks, especially on the hot side which expands and contracts in use. As above, the male end of a compression fitting will be too narrow and will be hard to make leak-proof.

I'm pretty certain you can get a version of flexi that has a compression fitting on the end - just make sure you get the right type. Otherwise you will need a stub of 15mm with a male tap spigot on the end (1" BSP, I think, but check). The end of a tap spigot is intended to mate with a washer.

I haven't done one for a while - some better-quality taps could be bought with flexi pipes - not any more?

Like you I hate the bend-once swaged-down copper pipes.

E.

PS: on leaking O-rings at the tap end, two things: (1) be VERY careful to tighten them well and not twist them when you do the 15mm end - it's really easy to loosten them off accidentally. (2) hard water seems to wreck black O-rings and washers. You can reduce the effect by lubricating the end of the pipe beyond the O-ring with Vaseline before you assemble it - it helps to seal and minimises the damage hard water does (it can't get to the crucial bit of the O-ring). It also makes the thread more slippery though so make sure you nip-up each pipe enough. Proper tap spanners can be very helpful for this, as access behind the sink is always awkward.

I'm nervous of using Bosswhite in this context as it doesn't do washers much good, and neither it nor PTFE goo (otherwise excellent) is very good for ceramic disk cartridges. Fitting those flexis to the tap really should be thought of as a one-time operation - you can't assemble and disassemble several times then expect it to be leak free.

Also check for brass swarf in the holes before you start! (DAMHIKT)

 

[Wuffles]

Forgot the link.

http://www.screwfix.com/p/wras-hose-15m ... 10mm/63404

These will be fine if you already have the rigid tails on the taps (and they're 15mm, which they should be). I've connected this kind of thing to the male output of an isolator many many times and not had a problem. If it leaked, add some ptfe between the metal connections, but it won't need it if the rubber washer sits well.

 

[mseries]

Thanks all for the help and advice. It's all a bit clearer now. The taps have 12mm copper tails, they are not expensive taps - which is why I want to make it easy to swap them in the not too distant future. I am changing the sink unit too so the new installation will be different to the existing one. The existing one has had the copper tails bent to avoid fouling the cabinet side and soldered to the feeds. I expect with copper tails in the new one the same thing will be required - I don't fancy my chances of bending them properly to meet the pipes. The feeds have a take off for the washing machine fairly low down and I am not sure there will be enough room for an isolator+flexi+copper tail above the junction - even if I could make the bends, it's something I'll take a look at when I get back to the house though.

 

[Phil Pascoe]

Just change the tap.. Why remove the tail?

because you can't unscrew the tails from monoblock taps while they are connected at the other end

Why not? You don't have to turn the whole pipe, just the nut. Fitting a flexible connector with an inbuilt isolator is no different to fitting an isolator then a flexible connector, just easier and neater (and one less joint to leak).

 

[mind_the_goat]

You could probably replace the copper tails with the flexi, if you can get a spanner in the confined apace. I wonder if wasting machine type isolators would be better than normal in-line types as these rely on washers to seal the joint and would not need to done up so tight. I have a box of flexi tails as they often come with the taps, but always seem to to be too short of have the wrong type of fitting.
If it was me I'd take the taps to my local (independent) plumbers merchant and ask there, but I'm lucky to have one that helps rather than looks at you like you are an idiot when you ask a question.

 

[mseries]

Just change the tap.. Why remove the tail?

because you can't unscrew the tails from monoblock taps while they are connected at the other end

Why not? You don't have to turn the whole pipe, just the nut. Fitting a flexible connector with an inbuilt isolator is no different to fitting an isolator then a flexible connector, just easier and neater (and one less joint to leak).

is there a nut at the tap end ? doesn't look like it to me, certainly isn't on the copper tails, hence I can't see how flexible ones could replace copper ones. They have a M12 male thread which screws into the matching threaded holes in the tap

 

[Phil Pascoe]

Ahh ... mine come down in larger pipe. I can't photograph mine or even remember how they connected other than that they're flexis with isolators - the clown who fitted my units fitted everything so tight that to get to the underside of the tap I have to lift the whole sink out. I can feel the compression fitting on the bottom, but that's it.

 

[Phil Pascoe]

Of course they should be 15mm. (I was thinking 12mm threaded = 12mm pipe. Tosh.) As Wuffles link or get push fits. You should be able to get them with inbuilt isolators.