Analysis of Friction and Wear Behavior of Polycrystalline Diamond Compact for Application in Subsea Valves

The subsea valve system is a key part of the subsea control system (SCS), which maintains the reliability of the subsea production system (SPS). With its current state, subsea valve systems cannot cope with the requirements to transition to the all-electric system (AES) and application of the SPS to deep- and ultra-deep-water locations. The primary reason is related to the limitations of the currently used coating material of subsea valve internals, tungsten carbide (WC), in terms of high operating pressures, sand production, and efficiency. With its expected low friction and high wear resistance, polycrystalline diamond compact (PDC) material is offered to replace WC as a top contact material in subsea valves. For this objective, PDC material's friction and wear behavior are investigated experimentally. The experimental section of the research involves tests with a reciprocating pin-on-flat tribometer, surface roughness measurements, and microscopical analysis of wear. Alongside PDC material, WC material is exposed to the same test process and conditions throughout the research for comparative analysis. The results show that comparing WC material in dry conditions, PDC material offers 61% friction reduction and 99.5% wear reduction; in lubricated conditions, it offers 40% friction reduction and 58% wear reduction. The findings highlight the potential impacts of this study on minimizing power usage for hydraulic and electric subsea actuators which consequently contributes to the reliability of the SCS and fills the existing research gap.