Patent ID: 11965611
Assignee: UNITED STATES STEEL CORPORATION
Field: Mechanical elements (Mechanical engineering)
Classification: CPC E  F | IPC F

Claim 9:
10. A threaded pipe connection comprising:
a first pipe comprising at least one pin thread extending in a helical direction around the first pipe along a longitudinal axis from a first pipe front surface towards a first pipe back surface opposite the first pipe front surface, each of the pin threads includes a pin crest width, a pin stab flank and a pin load flank, the pin crest width changes at a pin crest width rate of change; and
a second pipe comprising at least one box thread extending in a helical direction around the second pipe along the longitudinal axis from a second pipe front surface towards a second pipe back surface opposite the second pipe front surface and structured and arranged to connect to the first pipe, each of the box threads includes a box root width, a box stab flank and a box load flank, the box root width changes at a box root width rate of change, wherein the box root width rate of change is different than the pin crest width rate of change;
wherein the pin crest width is greater than the box root width forming a width bias;
wherein the at least one pin thread is tapered at a pin taper angle;
wherein the at least one box thread is tapered at a box taper angle;
wherein the box taper angle is different than the pin taper angle forming a taper angle bias;
the taper angle bias and the width bias are configured to concentrate stress on the pin load flank, box load flank, pin stab flank and the box stab flank, with the stress decreasing along the threaded pipe connection from the first pipe front surface towards the first pipe back surface; and
wherein the taper angle bias and the width bias are configured to orient the first pipe such that a pin thread adjacent the first pipe front surface is first to engage the box threads during rotation for the threaded pipe connection and each subsequent pin thread engages the box threads in an ordered and controlled manner.