Hello,
My new boiler is due to arrive soon and the oil filters at BES are available in 1/4 inch or 3/8 inch BSP taper connections. I understand there are BSP taper and BSP parallel but never having seen the two side-by-side I don't know what is the difference. Can anyone tell me?
They will be connected with 10mm copper so if I have the choice should I go for the 1/4" or the 3/8" connection, or won't 1/8" make much difference?
Thanks, Stephen.
Sorry to add to my own post but I have re-read the BES web site and it doesn't say anything about whether they are taper or not so I have emailed them to ask which they are. However, it would be nice to know the difference anyway ;)
Just get 1/4" bspt male to 10mm od copper stud couplings.Some people call them adapters but stud coupling is their proper name.Wade are my preferred manufacturer.Bsp is sized by nominal bore so the 1/4" refers to bore rather than od.
The taper ones are tapered and the others are not!
Most threads are parallel - the bolt does not get thinner as you go alog it.
The taper thread tapers at a ratio of 1:16 so a bolt cut with a taper thread will get thinner.
I assume you're connecting the oil filter into a run of pipe work. As long as the connectors on the pipe work and the filters match then you'll be OK.
Guy
-- -------------------------------------------------------------------- Guy Dawson I.T. Manager Crossflight Ltd snipped-for-privacy@crossflight.co.uk
Parallel Male Fitting fitted into a Parallel Female Port will need a sealing washer on the face.
Tapered Male Fitting fitted into a Tapered Female Port will need a PTFE Tape or Sealing Compound on the Threads..
Tapered Male Fitting fitted into a Parallel Female Port will need a PTFE Tape or Sealing Compound on the Threads.
Parallel Male Fitting fitted into a Tapered Female Port is a Bodge but can be made to work.
1/8" BSP = 10.3 mm OD 1/4" BSP = 13.8 mm OD 3/8" BSP = 17.2 mm OD 1/2" BSP = 21.4 mm OD 3/4" BSP = 26.6 mm OD 1! BSP = 33.5 mm OD
Taper threads seal on the actual threads (usually with PTFE tape wrapped round them). You just screw them in until you get to a wide enough part of the taper to make them a tight fit in the threaded hole. Radiator tails are a good example.
Parallel connections do *not* seal on the threads - but have a flange which comes into contact with a face (usually with a flat washer in between) when you screw them right in.
Thanks for the replies. It seems the filters are have parallel threads and the fire valve thread is tapered, so a real mixture.
I did look at wikipedia before posting but I never saw that page.
What washers would you use with oil, and why can't I find any on the BES web site?
Finally, I am confused that the firevalve is 1/4" but the filters are
3/8". Does 1/8" really make any difference and why are the fittings mixed? Why aren't they all of the same size?Thanks, Stephen.
than you think.
Post edited :)
I was told by an old plumber to put at least 15 turns of PTFE onto a tapered fitting used with oil.
He was right.
Cheers,
Paul.
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