Screw thread compatability - NPT & LP 1

[dyn11]

I have an application where a 1/2 " NPT male thread on an instrument is to be screwed into a 1/2" LP tapped hole. Apparently the LP and NPT threads are essentially the same however not exactly the same. Will this coupling be safe at a gas pressure of 6000 psi?

Does anybody know of a source of LP to NPT adapters?

 

[Hush]

LP thread form and pitch is identical to NPT. The difference is in the L4 dimension. The 1/2 NPT external thread is about 3/16" shorter than 1/2" LP.

Pressure rating depends on material used. API rates the 1/2" LP thread at 10,000 psi when using 60,000 psi minimum yield material.