Analysis on Contact Pressure for the Seal Structure of Repair Clamp with Wedge Contact Seals

Abstract Seal pressure is the key performance of repair clamp for subsea pipeline, which is generally designed by analyzing the contact pressure on each sealing surface of the seal structure. Research has shown that the weakest part of the clamp seal is the position where radial seal ring contacts axial seal strip. Usually for clamp seal structure the contact between radial seal ring and axial seal strip is tangent between a cylindrical surface and a plane. In order to improve the contact pressure of the position, a seal structure with wedge contact between seals that is tangent between a conical surface and a plane is proposed. 3D simulation analysis for the seal structure is carried out, and the contact pressures under four different wedge angles of 11°, 13°, 15° and 17° are analyzed. The minimum contact pressure is compared with that of the wedge angle of 0°. Simulation results show that the wedge contact will increase the contact pressure of the original weakest part, and the position of minimum effective contact pressure of the seal structure becomes the contact surface between two seal rings. The minimum contact pressure increases with the increase of the wedge angle. The wedge angle is recommended to be 13 ° more appropriate.