Sorry Rod, but this is not correct. Some sizes of BSP may be the same pitch as
NPT, I think, but not all, or maybe not any. The ones I know are different are
only 1 thread / inch different, but the biggest error here is that BSP comes in
two forms, straight and tapered. Most of the oil fittings we deal with on
British cars use the straight form. Thats why on oil coolers you see the
tapered seat to mate with the hose end. The threads are not doing any function
to seal, as a tapered pipe thread would. Even British banjo bolts on the oil
circuits, such as the ones on the side of your B series BMC block, are straight
BSP, not tapered. Note that the double ended male fittings screwed into the
block or filter head have a crush washer under the hex, to perform the seal.
Yes, many times, the pitch is only 1 thread off and you can jam them into each
other, but they are not the same and for reliable seal, the threads must match
and be the same form.
Also, there are American, or straight NPT threads, commonly found on the tube
through the center of a lamp which holds it together and which the wires pass
to get to the lamp base. It is straight 1/8 NPT. By the way, some catalogs
refer to BSP as British Straight Pipe, although this is probably a misnomer.
Roger
>>> <RodsINTOMG@aol.com> 08/21/00 10:17AM >>>
Brian has it right, BSP (I believe stands for British Standard Pipe) and NPT
(National Pipe Threads) have the same threads per inch and are both tapered
threads (as all pipe threads are). The NPT seals on the tapered thread,
whereas the BSP seals on a flange. Can you mix them? I have on my MGB with
great success. Earls and Aeroquip fitting that convert pipe threads to AN
should do the job. Use lots of teflon tape and tighten joints well.
It's also highly recomended that you get an Earl's or Aeroquip catalog and
explore your options. The mfg's catalogs show much more product than say a
Summet or other sale catalog.
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