Threaded connection with high compressive rating

Abstract

The surface areas available for absorbing compressive loading of a threaded connection are increased by increasing the engaged area of a torque shoulder in the connection and by reducing the spacing between the stab flanks of the threads. The areas are increased by increasing the dimensions of the components and by decreasing the machine tolerances permitted in manufacturing the components. The gap in the connection adjacent the torque shoulder is reduced so that the contact surface area of the torque shoulder is increased while the close proximity of the surrounding cylindrical walls of the connection reduces voids that can receive plastic deformation of the torque shoulder corners. The surfaces adjacent the torque shoulder are cylindrical in shape rather than being tapered to reduce machining costs and increase the speed of manufacture of the connection. The compressive loading of the connection provides an axial seal along the bearing surface with the torque shoulder and a radial seal in the near adjacent area of the surrounding cylindrical walls. An interference seal at the end of the box face and the pin nose isolates the engaged threads from the corrosive effects of fluids on either side of the connection. The provision of cylindrical walls in the threaded area reduces side wall galling, enables easier gauging and machining, and provides an increased contact area in the cylindrical surrounding areas.