Getting rather confused about compression fittings and thread sizings.

Take a 15mm straight coupler, e.g.

http://www.screwfix.com/app/sfd/cat/...88231&id=14921

The internal diameter if the fitting is obviously 15mm, to take
naturally 15mm pipe. But what is the thread size on either end?

Now take something like:

http://www.screwfix.com/app/sfd/cat/...12341&ts=05907

This is described as Female Iron Coupler Compression Fittings 15mm×½"

The 15mm must relate to the internal diameter and I guess the thread
size is the same on one end as the stright coupler. But what does the
1/2" relate to? The internal diameter on the other end or the thread size?


Help!

Graham

On Sun, 16 Jan 2005 20:09:41 +0000, Graham Jones
strung together this:

Getting rather confused about compression fittings and thread sizings.

Take a 15mm straight coupler, e.g.

http://www.screwfix.com/app/sfd/cat/...88231&id=14921

The internal diameter if the fitting is obviously 15mm, to take
naturally 15mm pipe. But what is the thread size on either end?

1/2"

Now take something like:

http://www.screwfix.com/app/sfd/cat/...12341&ts=05907

This is described as Female Iron Coupler Compression Fittings 15mm×½"

The 15mm must relate to the internal diameter and I guess the thread
size is the same on one end as the stright coupler. But what does the
1/2" relate to? The internal diameter on the other end or the thread size?

Thread size. For some reason all the pipes have gone metric but
anything threaded is still imperial. 15mm fittings = 1/2" threads.

Go figure.
--

SJW
Please reply to group or use 'usenet' in email subject

Graham Jones wrote:
Getting rather confused about compression fittings and thread sizings.

Take a 15mm straight coupler, e.g.

http://www.screwfix.com/app/sfd/cat/...88231&id=14921

The internal diameter if the fitting is obviously 15mm, to take
naturally 15mm pipe. But what is the thread size on either end?

Now take something like:

http://www.screwfix.com/app/sfd/cat/...12341&ts=05907

This is described as Female Iron Coupler Compression Fittings 15mm×½"

The 15mm must relate to the internal diameter and I guess the thread
size is the same on one end as the stright coupler. But what does the
1/2" relate to? The internal diameter on the other end or the thread size?


Help!

Graham

The reason for all this is that I am trying to determine whether this:

http://www.screwfix.com/app/sfd/cat/...12341&ts=05907

is the same as this:

http://www.screwfix.com/app/sfd/cat/...76620&ts=07117

but without the flexible hose. Do both items have the same diameters and
threads?

Thanks,

Graham

On Sun, 16 Jan 2005 20:26:38 +0000, Graham Jones
wrote:



The reason for all this is that I am trying to determine whether this:

http://www.screwfix.com/app/sfd/cat/...12341&ts=05907

is the same as this:

http://www.screwfix.com/app/sfd/cat/...76620&ts=07117

but without the flexible hose. Do both items have the same diameters and
threads?


Yes.

DG

Derek * wrote in message ...

On Sun, 16 Jan 2005 20:26:38 +0000, Graham Jones
wrote:



The reason for all this is that I am trying to determine whether this:

http://www.screwfix.com/app/sfd/cat/...12341&ts=05907

is the same as this:

http://www.screwfix.com/app/sfd/cat/...76620&ts=07117

but without the flexible hose. Do both items have the same diameters and
threads?


Yes.

DG

Well very nearly Derek. The flexible connector will be designed to fit on a
basin tap with the seal being made with a fibre washer (very likely to be
supplied in the pack) onto the annular end surface of the tap thread.
The 15mmx 1/2"female iron fitting will screw on a tapered male thread on a
pipe or other fitting and will be sealed by the thread jamming augmented by
PTFE tape or bosswhite &hemp.

Hope this helps

Bob

Graham Jones wrote:
Getting rather confused about compression fittings and thread sizings.

Take a 15mm straight coupler, e.g.

http://www.screwfix.com/app/sfd/cat/...88231&id=14921

The internal diameter if the fitting is obviously 15mm, to take
naturally 15mm pipe. But what is the thread size on either end?

Now take something like:

http://www.screwfix.com/app/sfd/cat/...12341&ts=05907

This is described as Female Iron Coupler Compression Fittings 15mm×½"

The 15mm must relate to the internal diameter and I guess the thread
size is the same on one end as the stright coupler. But what does the
1/2" relate to? The internal diameter on the other end or the thread size?


Help!

Graham

Thanks for everyones replies, a lot clearer now.

In an earlier contribution to this discussion,
Graham Jones wrote:


The reason for all this is that I am trying to determine whether this:

http://www.screwfix.com/app/sfd/cat/...12341&ts=05907

is the same as this:

http://www.screwfix.com/app/sfd/cat/...76620&ts=07117

but without the flexible hose. Do both items have the same diameters
and threads?

Yes, they both have a 15mm compression fitting one end and a 1/2" BSP female
thread at the other end.

However, I'm not sure whether the sealing arrangements of the 1/2" BSP bits
are the same as each other.

There are two different ways of sealing threaded joints. One uses parallel
threads and a washer - as in a tap fitting. The other uses a long parallel
female thread, and a slightly tapered male thread. The second sort actually
seals on the threads when the tapered bit is far enough in, using PTFE tape
or Boss White and hemp wound round the threads.

I suspect - but am not sure - that your first reference is designed to screw
onto a tapered thread. The second one (the flexible tap connector) is
definitely parallel, and seals against a face, using a fibre or neoprene
washer.

--
Cheers,
Set Square
______
Please reply to newsgroup. Reply address is invalid.

Thread size. For some reason all the pipes have gone metric but
anything threaded is still imperial. 15mm fittings = 1/2" threads.


Wonder why that is? What if you get a french threaded coupler? Would
that really confuse a UK plumber? :-)

M.

[Paul Barker]

Originally Posted by Markus Splenius

Thread size. For some reason all the pipes have gone metric but
anything threaded is still imperial. 15mm fittings = 1/2" threads.


Wonder why that is? What if you get a french threaded coupler? Would
that really confuse a UK plumber? :-)

M.

Yes, but gues what Frenchy stuff is turning up. Mostly the toilet inlets with Foreign thread come with an adapter (USA USE SAME FOREIGN SYSTEM) to 1/2". I haven't found a way to purchase them seperately.

15mm compression fittings all have 1/2" male threads on so these can be used without the nut and olive for certain jobs.

The same is not true for 22mm, these do not have a 3/4" thread. What a missed oportunity?

Very often parallel threads are made with parallel threads, just use a lot more ptfe than usual. Of course for gas the only parallel thread allowed is the Long Screw, but for water parallel threads are commonplace.

The message
from Paul Barker contains these words:

15mm compression fittings all have 1/2" male threads on so these can be
used without the nut and olive for certain jobs.

The same is not true for 22mm, these do not have a 3/4" thread. What a
missed oportunity?

They did once. I thought they changed decades ago but at Xmas I had to
replace an inline valve that had been bought only about 3 years
previously and found that to be 3/4" bsp while the replacement had the
finer thread.

--
Roger

On Tue, 18 Jan 2005 23:50:43 +0000, Lurch wrote:

On Mon, 17 Jan 2005 06:14:35 +0000, Markus Splenius
strung together this:

Thread size. For some reason all the pipes have gone metric but
anything threaded is still imperial. 15mm fittings = 1/2" threads.

Wonder why that is? What if you get a french threaded coupler? Would
that really confuse a UK plumber? :-)

Confused me first time around, had some turn up on some Armitage
toilet cisterns, bloody annoying!

It's not so much the thread that is frogified but the size.
It's 3/8 BSP which is not a common size in UK plumbing.

The 15mm-3/8"F couplers are becoming more widely available.


--
Ed Sirett - Property maintainer and registered gas fitter.
The FAQ for uk.diy is at www.diyfaq.org.uk
Gas fitting FAQ http://www.makewrite.demon.co.uk/GasFitting.html
Sealed CH FAQ http://www.makewrite.demon.co.uk/SealedCH.html

On Wed, 19 Jan 2005 21:27:01 +0000, Ed Sirett
strung together this:

It's not so much the thread that is frogified but the size.
It's 3/8 BSP which is not a common size in UK plumbing.

I sussed that eventually, unfortunately I'd already positioned the
15mm x 1/2" angled service valves accordingly before plastering the
wall up! The proximity of the male thread to the edge of the rear of
the pan cased a few difficulties too, I thought that was the problem
to start with then realised that the thread wasn't 1/2" BSP.
--

SJW
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