Imperial thread for Pipe coupling & Fittings 1

[Santosh Ingale]

I need one technical question help related to Thread
While preparing MTC Dimensional Standard ASME B1.20.1
I mentioned 1/4" NPT - Class 2A For Coupling externally threaded is it wrong.
Please help out of this question

 

[3DDave]

I don't recall classes for NPT threads. In UN threads class govern precision and clearance, but neither really applies to pipe threads.

Apparently NPTF threads have Class 1 and Class 2 to cover inspection requirements, but the thread spec is the same.

Ref:

https://www.industrialspec.com/about-us/blog/detail/npt-nptf-tapered-threads-and-leakproof-seals

 

[Santosh Ingale]

Hi 3DDave,
I appreciate your response please find attachment.Generally 2A- External threads & 2B- Internal threads there specified.
Let me know your review as generall when we talk about Limits,Fits & Tolerances I think it's right.
Kindly interpret.I marked your post as great
Thank you.

 

[3DDave]

There aren't 2A and 2B for NPT pipe threads.

You need to add the attachment by pasting the link to the uploaded file into your post.

 

[Santosh Ingale]

Ok,
Have look now it's here attached.
Kindly submit authenticatic view as per standard please.
Thank you

 

[3DDave]

Those aren't NPT threads. That page is for NPSM (straight) threads, which aren't tapered.

I can't authenticate because you are providing conflicting information. There is no 2A and 2B for NPT threads.

 

[Santosh Ingale]

Ok, Noted it's standard conflict nothing.Just a confirmation out of the confusion thanks and regards.