Tubular threaded joint having improved high torque performance
AssigneesNippon Steel & Sumitomo Metal Corporation, Vallourec Oil and Gas France
InventorsKunio Goto, Yasuhiro Yamamoto
Life of this patent
Estimating the term…
Abstract
A lubricating coating which can prevent the occurrence of galling even when makeup is carried out with a high torque and which has excellent rust preventing properties is formed on the contact surfaces of a pin and/or a box of a tubular threaded joint. The lubricating coating contains copolymer particles made from particles of an acrylic-silicone copolymer with an average particle diameter of 10-50 μm dispersed in a highly viscous matrix made from a mixture of a rosin-based substance selected from rosin and its derivatives, wax, a metal soap, and a basic metal salt of an aromatic organic acid (such as highly basic Ca sulfonate).
Claims12
A tubular threaded joint comprising a pin and a box each having contact surface including threads and an unthreaded metal contact portion, characterized in that the contact surface of at least one of the pin and the box has a lubricating coating comprising particles of a copolymer of a resin selected from a silicone resin and a fluorocarbon resin with a thermoplastic resin, said particles being dispersed in a viscous matrix having a complex shear viscosity of at least 3000 Pa-sec at 25° C.
Dependencies are inferred from the claim text.