American Pipe Threads (NPT) Stress
American Pipe Threads (NPT) Stress
(OP)
I am trying to determine stresses in NPT threads. I need to design a 6-8NPT threaded connection capable of withstanding 2000 PSI. The preferred material is a cast brass. I have been unsuccessful in locating any formulas or technical data to help determine stress in NPT threads. I expect to find a hoop stress component and a shear component acting on the connection due to stress induced by tightening the tapered connection together, hydrostatic pressure inside the connection, and axial forces pulling the components apart.
Initial testing on a prototype has shown failure due to both shearing of threads, and increased thread diameter of the internally threaded component.
Initial testing on a prototype has shown failure due to both shearing of threads, and increased thread diameter of the internally threaded component.





RE: American Pipe Threads (NPT) Stress