Patent ID: 11624460

Abstract:
A threaded connection with good internal-pressure and external-pressure sealability while preventing galling is provided. A threaded connection 1 includes a pin 10 and a box 20. The pin 10 includes a pin lip 11, a pin metal seal 13, and a cylindrical inner machined surface 14. The pin metal seal 13 includes a pin seal taper surface 16 and a pin seal curvature surface 17. The box 20 includes a box metal seal 22 parallel to the pin seal taper surface 16. The pin metal seal 13 sealingly contacts the box metal seal 22 at a seal point SP. The threaded connection satisfies the following expressions, (1) and (2), L>Lm>Ls  (1), andtb/tp>1.6  (2). L is the length of the pin lip 11; Lm is the distance between the tip AP of the pin and the end point of the cylindrical inner machined surface 14; Ls is the distance between the tip AP of the pin 10 and the seal point SP; tb is the wall thickness of the box 20 as measured at the seal point SP when the connection is made up; and tp is the wall thickness of the pin 10 as measured at the seal point SP.