Patent ID: 11898403
Assignee: FRAC STRING SOLUTIONS LLC
Field: Mechanical elements (Mechanical engineering)
Classification: CPC E  F | IPC E  F

Claim 8:
9. A leak-resistant threaded pipe connection, comprising:
a pin end having external pin threads with a thread taper, a pin nose having a secondary pin shoulder, a pin nose taper between the external pin threads and an annular seal bulge having an apex with an external diameter at the apex, and a pin nose cylinder between the annular seal bulge and the secondary pin shoulder,
a box end having internal box threads adapted for connection with the external pin threads, a secondary box shoulder, a box pre-taper area, a tapered seal area, and a box post-taper area between the internal box threads and the secondary box shoulder, the tapered seal area being tapered at an angle greater than the thread taper, the box pre-taper area having an internal diameter that is larger than an external diameter of the apex of the annular seal bulge and the box post-taper area having an internal diameter that is smaller than the external diameter of the apex of the annular seal bulge;
whereby on initial make-up of the leak-resistant threaded pipe connection to a recommended make-up torque, the annular seal bulge is plastically deformed and coined against the tapered seal area of the box end to provide a metal-to-metal fluid seal.