4-ROUND THREAD FORM

摘要

An apparatus is disclosed that forms a piping thread form of four threads per inch pipe (TPI). The thread form is configured to have a load flank, a load flank angle, a stab flank, a stab flank angle, a crest, and a root. Hydrostatic pressure tests using the 4-round thread form at pressures of 4,500 psi and greater resulted in failures due to thread leaks. Tensile tests using the 4-round thread form at loads of 187,400 lbs. and greater resulted in shearing at forces of 3,535 psi and greater.

主权项

1. A thread form comprising:
a predetermined number of threads per inch; a load flank having a load flank angle; a stab flank having a stab flank angle; a crest portion between the stab flank and the load flank; and a root portion between the load flank and the stab flank, wherein the load flank angle is approximately between 2.4 and 4.0 times the stab flank angle in the root portion.