Nipple threads

[peter_sm]

I have a couple of plumbing nipples protruding from the wall that I have taken the hardware off to do some plastering. I have noticed the new shower head and bath spout that I have are a fairly loose fit on the nipple thread.

Now when I say loose I mean they are not getting tighter like a normal tapered thread, as they are not tapered.

What is the standard seal required to make sure they do not leak when I put them back on. Teflon tape only? A type of sealant? Lots and lots of Teflon tape?

They also will bottom out I have noticed, and this then leaves the hardware fitted pointing in the wrong direction. What to do with this situation? Cut the nipple back the required amount of thread?

[journeyman Mick]

Peter,
if your new fittings have a clean, square shoulder machined inside them you could get around your problems by getting the right sized "O" ring to sit in the fitting and seal against the end of the nipple. Thos will only work if both the nipple and the fitting have clean square mating surfaces.

Mick

[Metal Head]

Hi Peter,

Now when I say loose I mean they are not getting tighter like a normal tapered thread, as they are not tapered.

I couldn't quite grasp what you are saying but if they are not getting any tighter then are you matching the correct diameters together. I know from past experience it is easier to match a tapered item with a parallel one and vice-versa. I also had the problem when I came to put the new fittings (bath spout & shower head) on the existing nipples that both nipples were too short (the items didn't bottom out on the nipples). Thus, I placed some washers (stainless steel) to fill up the gap and then placed the "O"ring in last before tightening the items up with the correct sized spanner. I also had put teflon tape on the nipples. Remember to put the tape on in a anti clockwise direction. You can when using larger threads use hem and sealing paste.

I hope this helped.

Regards
David

[pawnhead]

I also had put teflon tape on the nipples. Remember to put the tape on in a anti clockwise direction.

I'm no plumber, but I've always put it on clockwise. The same direction that you're screwing the female on, to stop the tape unraveling as you screw.
I've had the same dilemma, but after I'd put on at least fifteen layers of teflon, there were no leaks. It didn't bottom out, and I didn't use an O ring.
Silicone around the nipple before you screw on the shower head as well. You may get a bit of water behind the flange that gets inside your wall otherwise.

[peter_sm]

Aha. I didn't know about the O rings. There was none on there. There was massive amounts of teflon on the shower head. It makes a lot of sense, as you can get it sealed without having to turn it like crazy to get it to seal the hardware in an 'upright' position.

I am used to automotive applications where the fittings into the engine block for water are all tapered and seal with just a smear of silastic, the taper does the sealing.

[journeyman Mick]

Peter,
the O rings aren't "supposed" to be there, it's just a way of getting round certain problems.

Mick

[Tools]

Plumbing fittings aren't tapered, and all you should be using to seal the joint is teflon.You can dry fit the tap without tape to see how many turns you get so that you can leave the tap in the correct position.Then remove it, tape it up clockwise, and tighten the correct number of turns.

Tools

[journeyman Mick]

Tools,
"iron" threads are parallel (male iron, female iron)
BSP are tapered (British Standard Pipe).
The two are partly compatible as the thread pitch is the same but obviously a female parallel thread isn't going to go very far onto a male BSP. By the sound of it, Peter has parallel thread stubs that he's trying to fit tapered fittings onto. Or possibly he has tapered stubs that haven't been cut as far down as the tapered fittings he's trying to fit.

Fun isn't it, this plumbing business.

Mick

[Tools]

I stand corrected on the threads.

Tools

[Metal Head]

I stand corrected on the threads.

Tools

It didn't bother me if you were right or wrong because I had Swaglok fittings in mind which maybe not classed as plumbing fittings. However, I have used them on aircraft as well as for scientific equipment which can be fatal if they leak (not tightened up enough) without the correct OH&S safety equipment in place (or being worn by the operator).

In regard to applying the teflon tape to the thread Pawnhead is correct. I was also correct because I was looking at it from behind as the male nipple enters the female threaded hole.

Regards
David

[Tools]

What are swaglok fittings? I tried to google them but can't see what they are.

Tools

[Metal Head]

What are swaglok fittings? I tried to google them but can't see what they are.

Tools

Sorry Tools - it is spelt SWAGELOK

Here are a couple of links

http://www.swagelok.com/

http://www.swagelok.com.au/

[bricks]

All you need to do is...

go to store
buy pink thread tape ( teflon)
wrap it around ' bout 6-8 times
put your spout, showerhead ( insert plumbing do-hiky here) on

it wont leak because its not under pressure ( it has a big massive hole in one end)

if the teflon keeps slipping on the thread, scratch the thread arcoss using a hacksaw blade on edge

Do not use o-rings, washers, or anything else they may wreck your tapware.

[Skew ChiDAMN!!]

For std. parallel fittings, teflon tape and... the plumber's secret helper: Hawkin's Paste. Available at any good plumber's supplies.

Just a bead of it, smeared onto the thread. A can of it is cheap and will last the average home handyman a lifetime.

[bricks]

Hawkins paste wont actually make a seal it is only an oil based lubricant and tho will probably do no harm and make the nipple turn easier, it aint goona help.

If you have trouble with getting a seal do this..

Roll the teflon in between your thumb and fore finger so it becomes a thin rope, lay the rope in one thread about 3/4 of the way down the nipple and wrap it round like an o-ring only one or two times to fill up the thread. Then wrap flat tape round 2 or 3 times to hold it in place , when you put it in it will not leak.I am a plumber and this is what i do when putting new fittings into old fittings which are worn out.