Orientation of bib taps?

Near enough yes, wind on threads but multiple winds near to tap end of thread, makes a custom PTFE washer in effect..

Just to be clear, I'm talking about combining these two parts:

Compression Wallplate Elbow 15mm x 1/2"

Hose Union Bib Tap with Double Check Valve 1/2" DZR

I was under the impression that if you install the elbow so that supply pipe is coming straight down to it, the tap should screw all the way into it & end up pointing down. (I'm pretty sure that's what I did with the old ones, which were removed as part of a kitchen renovation, so I've installed new ones in a different place outside.)

In practice, however, I installed two of these the same way but they ended up pointing in slightly different directions, neither straight down. I ended up packing a couple of fibre washers in each elbow until I got the right direction. What am I missing?

Thanks.

. What am I missing?

Nothing - it is usual

I tried it with and without PTFE tape on the threads. Both ways, the tap went in farther than I expected, ending up pointing down and left rather than just down.

So experimenting with different combinations of fibre washers until the result is pointing the right way is really how you have to do this?

Your expectations of accurate threading of both parts is way too high. ;-)

I think this is probably a case for old fashioned hemp and some sort of plumber?s sealing compound. Fiddle with both until you?ve got it right.

PTFE tape will work if you use enough but it?s really too slippery and can squidge out as you tighten things up.

Tim

I believe Jim meant make your own washer with ptfe, not wrap it around the threads.

Wrap some hemp and plumbers mate around the threads, then you'll find that the thread tightens earlier and you can set it in any position without leaks.

Or you can wind the PTFE tap on the threads progressively thicker near the back of the fitting until the threads jam at the point you want them to.

On 16/05/2019 19:30, Roger Hayter wrote: .

That's the theory.

PTFE of course is like a woman. Smooth to the touch and easily wrapped around your fingers. But it will not actually do what you want it to do.

Loctite 55 Pipe Sealing Cord a modern PTFE alternative to old style hemp and plumbers mait.

I find that hemp is better for this sort of thing.

IME it works alright on brass. But Fernox LS-X will probably work on

I've always had that issue. I guess its the variability of the treads on both parts. Brian

Had this with a pair of Bristan 1901 bib taps and upstands. One was perfect; the other was >150 deg. out. I had nothing that would correct the bad one, so I swapped them over and found that nylon washers just did the job and made them both the same. Needed a bit more tape in on of them but it's not a noticeable difference. I was lucky to have the washers - in an Aldidl kit, IIRC.

Given the total price of the fittings, they should be correct to start with.

It is technically impractical with ordinary manufacturing to make the two brass parts and a (variable) standard washer do up to a precise predicted angle. And it is not what is expected by plumbers. Not least because the supply pipe can come from any quadrant (or any intervening angle if one is untidy enough).

Thanks (to everyone else too) for the tips. I'll keep fiddling with washers, hemp, and so on but...

...there ought to be a better way.

Looks interesting, thanks.

Also interesting, thanks.