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What is this pipe thread?

ChrisJ
ChrisJ Member Posts: 11,970
Hi all,

I need to make this part and I have no idea what the thread is yet.   It's 1" sch 40 pipe 1.05" ID but the thread is much finer than NPT.   The nipple next to it, is supposed to be 1" BSPT which I got from McMaster but it looks just as course as NPT.


Any ideas what this could be?  It does appear tapered.


Single pipe quasi-vapor system. Typical operating pressure 0.14 - 0.43 oz. EcoSteam ES-20 Advanced Control for Residential Steam boilers. Rectorseal Steamaster water treatment

Comments

  • Dave0176
    Dave0176 Member Posts: 1,172
    edited September 2020
    Electric straight threads
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  • Zman
    Zman Member Posts: 6,980
    What is it off of?
    If it is American, it may be national pipe tapered fuel (NPTF).
    The most likely import would be, British Standard Taper Pipe Thread (BSPT)
    "If you can't explain it simply, you don't understand it well enough"
    Albert Einstein
  • ChrisJ
    ChrisJ Member Posts: 11,970
    Dave0176 said:

    Electric straight threads

    NPS is the same thread pitch as NPT, no?
    Single pipe quasi-vapor system. Typical operating pressure 0.14 - 0.43 oz. EcoSteam ES-20 Advanced Control for Residential Steam boilers. Rectorseal Steamaster water treatment
    mattmia2wyo
  • pecmsg
    pecmsg Member Posts: 2,321
    There is NO taper on the upper thread!

    Is that an O-Ring on the right?
  • ChrisJ
    ChrisJ Member Posts: 11,970
    Zman said:

    What is it off of?
    If it is American, it may be national pipe tapered fuel (NPTF).
    The most likely import would be, British Standard Taper Pipe Thread (BSPT)

    Sadly in the world I work in it's not that simple.
    I can't say what it's from, but it could literally be anything, including custom.

    I'm hoping there's a fine pitch tapered thread for pipe, though. BSPT looks way too course.
    Single pipe quasi-vapor system. Typical operating pressure 0.14 - 0.43 oz. EcoSteam ES-20 Advanced Control for Residential Steam boilers. Rectorseal Steamaster water treatment
  • ChrisJ
    ChrisJ Member Posts: 11,970
    pecmsg said:

    There is NO taper on the upper thread!

    Is that an O-Ring on the right?

    That's thread locker that is left behind.
    It's very clearly a tapered thread in person, the camera messes it up.

    I work in a machine shop, if I can't tell tapered from straight I need to just go home. ;)
    Single pipe quasi-vapor system. Typical operating pressure 0.14 - 0.43 oz. EcoSteam ES-20 Advanced Control for Residential Steam boilers. Rectorseal Steamaster water treatment
  • Zman
    Zman Member Posts: 6,980
    Hmm,
    Do you have a pitch count? You may need to break out the gages and look through countless charts...
    "If you can't explain it simply, you don't understand it well enough"
    Albert Einstein
  • ChrisJ
    ChrisJ Member Posts: 11,970
    Zman said:

    Hmm,
    Do you have a pitch count? You may need to break out the gages and look through countless charts...

    That's what I'm hoping to avoid.
    Luckily it doesn't need to be exact as I'm making both pieces but I was hoping it was a common thing.

    Oddly enough I count 14 TPI by eye, which is the same as 3/4 NPT but not 1".

    Single pipe quasi-vapor system. Typical operating pressure 0.14 - 0.43 oz. EcoSteam ES-20 Advanced Control for Residential Steam boilers. Rectorseal Steamaster water treatment
  • Jamie Hall
    Jamie Hall Member Posts: 17,049
    I just have to wonder... is it metric, by any chance?
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
  • mattmia2
    mattmia2 Member Posts: 3,957
    Is it an adjustable die for 1/2 and 3/4" that was made to cut 1" thread?
  • mattmia2
    mattmia2 Member Posts: 3,957
    It doesn't look like the angle or geometry of the groove is the same as NPT either. There was some sort of fine pipe thread in the US as well I think. BSPT is a different angle than NPT if I recall, but this is probably neither. Is there any reason to believe it wasn't something someone just cut on a lathe to connect the 2 parts?
  • Matt_67
    Matt_67 Member Posts: 197
    My guess is metric taper - maybe M33 x 2.0?
  • Steve Minnich
    Steve Minnich Member Posts: 2,674
    NPS is a straight thread.
    Steve Minnich
    Minnich Hydronic Consulting & Design, LLC
    [email protected]
  • ChrisJ
    ChrisJ Member Posts: 11,970

    NPS is a straight thread.

    It's straight and as far as I know it's the same pitch as NPT.
    Single pipe quasi-vapor system. Typical operating pressure 0.14 - 0.43 oz. EcoSteam ES-20 Advanced Control for Residential Steam boilers. Rectorseal Steamaster water treatment
  • EBEBRATT-Ed
    EBEBRATT-Ed Member Posts: 10,268
    I know what it isn't and it's not a conduit thread.
  • BillyO
    BillyO Member Posts: 274
    lets see die you used to thread it. why are we guessing at this?
  • ratio
    ratio Member Posts: 2,923
    BillyO said:

    lets see die you used to thread it. why are we guessing at this?

    Hmmm…
    CanuckerZman
  • psb75
    psb75 Member Posts: 463
    BSPT-- British Standard Pipe Thread is straight, not tapered.
    NPT-- NationAL Pipe Thread is tapered.
    In the picture: the top pipe looks like straight thread.
    The bottom fitting from McMaster (close nipple?) looks like tapered NPT.
  • ChrisJ
    ChrisJ Member Posts: 11,970
    psb75 said:
    BSPT-- British Standard Pipe Thread is straight, not tapered. NPT-- NationAL Pipe Thread is tapered. In the picture: the top pipe looks like straight thread. The bottom fitting from McMaster (close nipple?) looks like tapered NPT.
    BSPT is British Standard Pipe Taper
    You're thinking of BSPP which isn't tapered.


    Single pipe quasi-vapor system. Typical operating pressure 0.14 - 0.43 oz. EcoSteam ES-20 Advanced Control for Residential Steam boilers. Rectorseal Steamaster water treatment
  • psb75
    psb75 Member Posts: 463
    You are correct. My bad. BSPT is British Standard Pipe Taper and BSPP is British Standard Pipe Parallel (straight threads).
    I've encountered BSPP threads on Myson panel radiators. I've even used NPT fittings on them with pipe dope and MANY wraps of tape. They did seal.
  • mattmia2
    mattmia2 Member Posts: 3,957
    I'm guessing this is the die that was used to thread it:
    https://i.ytimg.com/vi/sYfHedtUsCs/maxresdefault.jpg
    Zman
  • ChrisJ
    ChrisJ Member Posts: 11,970
    mattmia2 said:
    I'm guessing this is the die that was used to thread it: https://i.ytimg.com/vi/sYfHedtUsCs/maxresdefault.jpg
    That's a cute little thing :)


    Single pipe quasi-vapor system. Typical operating pressure 0.14 - 0.43 oz. EcoSteam ES-20 Advanced Control for Residential Steam boilers. Rectorseal Steamaster water treatment
    mattmia2