Results 1 to 12 of 12

Thread: Anyone know about BSPP pipe fittings?

  1. #1

    Anyone know about BSPP pipe fittings?

    I have a power washer unloader (General Pump ZK1) that has an "3/8 BSPP-M" outlet. I understand that BSPP is a parallel thread that requires a washer to seal, but this fitting doesn't have a flat face for a washer to press against; rather, it has a concave flare that would seem to be the sealing surface.

    So what's this called? Is there such a thing as a BSPP-M fitting that seals with a flare instead of a washer? I just can't seem to find the right term to describe this. I'm ultimately trying to connect a 3/8 NPT-M hose to it...
    Attached Images Attached Images

  2. #2
    You need to look for British standard parallel pipe swivel. BSPP stands for British standard parallel pipe but that's a straight thread fitting with the cone seat in the center. It's not alive swivel. But the style of fitting you need is called a swivel

  3. #3
    Thanks, Mark.

    I bought a fitting like this, but it's just a straight BSPP female coupler, so while it screws on just fine, it doesn't have any sealing surface (no cone or o-ring):
    https://www.mcmaster.com/4936K949/

    Are you saying I need something like this? It's hard to tell from the drawing if this has the mating cone:
    https://www.mcmaster.com/4936K376/

  4. #4
    I didnt find a female in a quick search but I believe you need to be looking for something like this:

    https://www.new-line.com/fittings/or...x-fbspp-swivel

    and the part number N9023-06-06 in that list would be a -06 (3/8") male npt to -06 (3/8") female bspp swivel.

    N9023-06-06

    I dont see any of those in McMaster. Your best bet would be a full service local hydraulic shop like a Parker Store if there is one in your area. That fitting above doesnt get you to female, you'd have to use a 3/8" NPT coupling to get to female but nothing pops up in female on a quick search.

  5. #5
    These are europe but you can click on the diagram and see the cone seat.

    https://www.customfittings.com/bspp-...t-male-adaptor

  6. #6
    Quote Originally Posted by Dan Friedrichs View Post
    Thanks, Mark.

    I bought a fitting like this, but it's just a straight BSPP female coupler, so while it screws on just fine, it doesn't have any sealing surface (no cone or o-ring):
    https://www.mcmaster.com/4936K949/

    Are you saying I need something like this? It's hard to tell from the drawing if this has the mating cone:
    https://www.mcmaster.com/4936K376/
    Dan, is it possible that the fitting seals the face of the fitting (outer end of the threads), rather than sealing against the shoulder...?? Much like a hose bib and hose connection. A (rubber) flat washer 'inside' the receptacle then might be the resilient seal.

    (Just scatter-shooting based on the design - - I'm not sure I've ever had a BSPP fitting in my hands other than as an accident perhaps.)

    *************
    I got curious, and I should have looked first....

    This is a description of the 'seal mechanism':
    BSPP pressure gauges have a longer male thread and use a copper crush washer that is squeezed in between the bottom of the male fitting and the bottom of the female BSPP hole forming a pressure tight seal. No thread sealant is needed to form a seal.
    So it sounds like it does seal against the thread face.

    Maybe search for "BSPP bonded seal" - it looks to be a steel washer bonded to inner flex 'gasket' intended for sealing in this manner, but not copper based.

    Or there does appear to be a shoulder sealing option: This might be a source or maybe this - - or at least narrow your search terms?
    Last edited by Malcolm McLeod; 11-25-2020 at 10:12 AM. Reason: curiosity kills

  7. #7
    Join Date
    Jul 2007
    Location
    Inkerman, Ontario, Canada
    Posts
    1,389

  8. #8
    Join Date
    Jan 2014
    Location
    Elyria, Ohio
    Posts
    45
    Dan,

    I think Mark is on the right track. The shop I work for makes some British Pipe fittings, but not like these. Incidentally. British Pipe threads are basically identical to ours, except the thread form is 55° instead of 60°. Male BSPP threads are "not suitable for pressure tight joints", so they need some other form of mechanical seal, like a gasket or flare seat.

  9. #9
    https://www.adaptall.com/info-tutori...ng-methods.php

    Handy little tutorial on identifying tube fitting seal types.

  10. #10
    Quote Originally Posted by Malcolm McLeod View Post
    https://www.adaptall.com/info-tutori...ng-methods.php

    Handy little tutorial on identifying tube fitting seal types.
    Right, nice link pertaining to the fitting show in his original post. BSPP cone seat.

  11. #11
    Join Date
    Feb 2010
    Location
    Mt Pleasant SC
    Posts
    721
    Northern tool probably has it.

  12. #12
    Quote Originally Posted by Mark Bolton View Post
    I didnt find a female in a quick search but I believe you need to be looking for something like this:

    https://www.new-line.com/fittings/or...x-fbspp-swivel

    and the part number N9023-06-06 in that list would be a -06 (3/8") male npt to -06 (3/8") female bspp swivel.

    N9023-06-06

    I dont see any of those in McMaster. Your best bet would be a full service local hydraulic shop like a Parker Store if there is one in your area. That fitting above doesnt get you to female, you'd have to use a 3/8" NPT coupling to get to female but nothing pops up in female on a quick search.
    Thanks, Mark - that's what I need! Looks like the term is "BSPP swivel". I found the same on a different site for $8 with free shipping, so I guess you can't beat that. Surprised McMaster doesn't seem to have it. Thank you!

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •