<![CDATA[Structural strainers play a vital role in oil and gas processing facilities by removing solid contaminants from process fluids and protecting downstream equipment. In a Low Temperature Separation Unit (LTSU), a premature failure occurred at the handle punching plate connection of a strainer after approximately five years of continuous operation. This study aims to identify the root cause of the failure and to evaluate improved design configurations capable of withstanding operational loads. A coupled Computational Fluid Dynamics (CFD) and Finite Element Analysis (FEA) methodology was employed. CFD simulations were conducted to determine internal flow characteristics, pressure distribution, and pressure drop under both normal and contingency operating conditions. The resulting fluid-induced pressure loads were transferred to structural models for FEA to evaluate von Mises stress, displacement, strain, and unity check (UC) values for three designs with different punching plate thicknesses. The original design (Geometry A) exhibited high stress concentration at the handle–plate interface and UC values exceeding allowable limits, explaining the observed field failure. Geometry B showed improved performance under normal conditions but approached critical limits during contingency operation. Geometry C demonstrated the best structural integrity, maintaining UC values within acceptable limits in all cases while reducing peak stresses and deformation. The results confirm that insufficient plate thickness was the primary cause of failure and that increasing thickness significantly enhances structural reliability. The study demonstrates that the coupled CFD–FEA approach is an effective tool for failure diagnosis and design optimisation of process equipment subjected to fluid-induced loading in oil and gas operations.]]>
