Patent ID: 7438329

Claim:
A threaded pipe connection, comprising: a coupling body constructed of standard coupling stock and having internally formed coupling threads, first and second pins formed at the ends, respectively, of first and second tubular pipe joints, first and second pin threads formed, respectively, along the external surfaces of said first and second pins, said first and second pin threads adapted to mate with said coupling threads to form a structurally joining connection and pressure seal between said first and second pins and said coupling, said first and second pins having first and second annular pin faces, respectively, formed along the axial end surfaces of the axial ends of said pins, each said pin face having a radial thickness defined between the internal diameter and the external diameter of the tubular pin on which it is formed, said first and second pin faces being adapted to engage each other at the approximate axial midpoint of said coupling when said first and second pins are fully mated with said coupling, said coupling being free of any torque shoulders for engagement by said first and second pins, first and second pin noses formed on said first and second pins, respectively, extending axially away from their respective pin faces by first and second pin nose lengths, respectively, the axial length of each of said pin noses being equal to at least 80% of the axial length traversed by two turns of the threads on the respective pins on which they are formed, said pin noses being at least partially structurally unconnected with said internal coupling threads when said first and second pins are fully mated with said coupling whereby axial forces in said coupling at radial locations adjacent either of said pin noses are not directly transmitted between said coupling and said pin noses, and a negative load flank thread geometry in threads of said first and second pins and the mating coupling threads, whereby radially compressive forces are imposed between said first and second pins and said coupling following engagement of said pin nose faces during torque application in the make-up of said connection.