NPT connections per API 6A

[toriche]

Does anybody know why API 6A designates NPT threads acceptable only up to 10,000 psi (Section 4.4.4.2.a)?

Are these not safe at higher pressures?

for 15k ansd 20k applications, API 6A recommends coned-and-threaded connections (Section 4.4.4.2.b).

Thank you.

 

[JStephen]

"Not safe at higher pressures" sounds like a reasonable guess. Either that, or can't be consistently sealed at those pressures.