Tribological investigation of contact pairs applied in metallic gate valve seals for onshore application

Abstract

Valves are equipment used in fluid management in industrial processes. Among the components of a valve, the set considered most critical for its operation and performance is the obturator sealing system, whose function is to make the fluid tight. This paper aims to analyze the tribological performance of two pairs in contact used in gate valves for onshore applications in oil installations. The specimens were manufactured using martensitic stainless steel with 13Cr as base material, varying the surface hardening processes under the following conditions: (A) heat treated and (B) Stellite 6 deposited by Plasma Transferred Arc Welding (PTAW). Pin-on-disc tests (PoD) were executed to compare the tribological performance of A/B and B/B configurations. In disc A versus pin B, the predominant wear mechanism was adhesion, resulting in a material pullout. For disc B versus pin B, the wear mechanism started with adhesion, followed by transfer film formation, generating elongated abrasive marks in the direction of movement on the surfaces of the pin and disc. With the results obtained, it was found that pair B/B showed less wear and friction. Based on these results, it is possible to indicate the use of the B/B pair for applications in valves that commonly require more activations and lower efforts for equipment actuation.