Getting rather confused about compression fittings and thread sizings.
Take a 15mm straight coupler, e.g.
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:
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?
The 1/2" refers to 1/2"BSP (British Standard Pipe) thread. This is the
thread that would have been cut on old style thickwall water or steam pipe
that was 1/2" bore.
Looking at modern pipe which is thinner wall and indeed the fitting you
have, there is nothing you can measure which will be 1/2"
It is all designed to confuse the beginner - so don't worry.
Yes, but gues what Frenchy stuff is turning up. Mostly the toile
inlets with Foreign thread come with an adapter (USA USE SAME FOREIG
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 b
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
Very often parallel threads are made with parallel threads, just use
lot more ptfe than usual. Of course for gas the only parallel threa
allowed is the Long Screw, but for water parallel threads ar
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
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.
Please reply to group or use 'usenet' in email subject
The reason for all this is that I am trying to determine whether this:
is the same as this:
but without the flexible hose. Do both items have the same diameters and
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
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
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