Talk:British Standard Pipe

External links

• Georgefischer Co.

The above link no longer works. Peter Horn 19:58, 28 August 2006 (UTC)

Odd sizes

Where do the sizes 5/8, 7/8, 1 3/4, and 2 1/4 that are currently listed in the table come from? None of the British, German, European or ISO standards that I checked mention them. If nobody can provide an authoritative source for these sizes (e.g., some national standard), I'll remove them from the table. Markus Kuhn 10:11, 3 September 2006 (UTC)

Now removed.

Outer pipe diameter

Could you please provide a reference for the recently added outer-diameter inch figures? An ISO or BSI document preferably. BS EN 10226 does not contain any pipe dimensions, only thread dimensions. Therefore, also the term "Pipe size" is misplaced here, the standard says "Thread size". Markus Kuhn 16:36, 5 September 2006 (UTC)

Parallel/tapered

I want to know if it's possible to screw a tapered male thread into a parallel female thread, or vice versa. Someone must know this?IMacThere4iAm 09:35, 26 October 2006 (UTC) In the article:

Jointing threads: These are pipe threads for joints made pressure-tight by the mating of the threads. They always use a taper external thread, but can have either parallel or taper internal threads.

This means a male BSPT (tapered) fitting will seal happily onto a female BSPP (parallel).

It is preferable to insert a tapered male fitting into a parallel female fitting. This means that thread engagement increases progressively from front to rear and sealing occurs towards the end (rear) of the male thread. If a parallel male is inserted into a tapered female, the sealing point occurs at the front (start) of the male thread, and all the threads behind it have progressively less and less engagement thus making a leak more likely. — Preceding unsigned comment added by 83.105.6.114 (talk) 12:10, 7 July 2011 (UTC)

Letter code

Any idea, where the letters G for parallel and R for tapered thread (as well as Rp and Rc) come from? Are these derived from some word in some language? Markus Kuhn 14:01, 10 February 2007 (UTC)

I'm not sure - we use BSPP and BSPT for _P_arrallel and _T_apered. 212.108.17.165 10:20, 2 April 2007 (UTC)

-- It's G for 'Gas', R is 'Rohr'(german for pipe), P is 'Parallel', C is Conisch (tapered) —Preceding unsigned comment added by 212.178.148.98 (talk) 14:39, 2 November 2010 (UTC)

Add link

I later found the long and useful Wiki article on Screw Threads, which should be linked here. Clwydd (talk) 18:55, 21 July 2009 (UTC)

It is in the first sentence. Wizard191 (talk) 20:22, 21 July 2009 (UTC)

inch v. mm nomenclature

An authoritative comment should be made about the following:

Strictly speaking, BSP threads should only be referred to using the fractional inch-based numbers, eg, 3/8, 1/2, 3/4, 1, etc. Neither the word inch, nor the symbol " should be used, because no such references are used in the Standards.

In particular, the commounly accepted metric (mm) equivalents of these inch sizes, eg, 10mm, 15mm, 20mm, 25mm should not be used because again, the Standards contain no such references.

Also, the equivalent metric pipe sizes, eg DN10, DN15, DN20, DN25 (where DN means nominal diameter of the pipe) etc should not be used because again, the Standards contain no such references, and at any rate, these sizes refer to pipe sizes, not thread sizes or forms.

However, in practice, the mm sizes of 10, 15, 20, 25, etc are very commonly used, so perhaps the discussion should acknowledge this, and if so, the mm number for every thread size should be listed, and a determination made as to whether DN or mm should be quoted. My own view is that DN is preferable because this refers to the pipe size, and any given pipe size can only be threaded to the same thread size, whereas mm is an exact mm dimension but one which has no direct relationship to the thread size, eg, 1/2" is 12.7mm not 15mm, and 3/4" is 19.1mm not 20mm, etc. —Preceding unsigned comment added by Jgrahamssmith (talk • contribs) 02:51, 22 April 2010 (UTC)

Nominal size

Why isn't the nominal size givne in fractions eg 3⁄4? In my umpteen years of working with threaded fittings I have never seen a part advertised as 0.375 always as 1⁄3/8. Dash sizes are seldom seen either. Dash sizing could do with an explanation, though it appears to be the nominal size expressed as sixteenths this is not stated. GraemeLeggett (talk) 15:30, 6 September 2011 (UTC)