Erosion estimation of a gate valve operating in sand-water flow

Gate valve is widely used in oil and gas industry. It is an on/off valve, but sometimes it is also used for regulating the flow. The presence of sand particles in production fluids imposes danger of erosion to gate valve and associated downstream pipe, and may result in failure of valve or leakage from the pipe. In this study, the erosion of a gate valve is numerically investigated to collect preliminary data in view of future experimental testing. Particularly, simplified prototypes of the device, in which the main features of the gate valve in three openings conditions (25%, 50% and 75%)are kept, have been simulated. The standard, most widely used methodology for erosion prediction is employed. That is, first, sand-water two-phase dilute flow is modeled using an Euler-Lagrange numerical approach in a computational fluid dynamics (CFD) simulation software. Afterwards, erosion predictions are made using an embedded utility in a commercial software and an in-house code of the FluidLab research group, which both rely on some semi-empirical erosion models. After validating the fluid dynamic characteristics of the prototypes with respect to experiments in the absence of sand, a sensitivity analysis is made in order to investigate the robustness of the wear estimates upon the different parameters of the erosion prediction model. The numerical simulations indicated that the structure of the particle equation of motion has non-negligible effects on erosion, and that parameters like the restitution coefficients, and the shape of the abrasive particles non-spherical factors are effective as well. Above all, the used erosion model exerts the main influence on the erosion predictions. The work allowed identifying the main features of the erosion process, thereby providing useful information for arranging the experimental campaign.