Objective Pilot-operated surge relief valves play a critical role in safeguarding oil pipelines against surge pressure-induced damage. Therefore, investigating the factors affecting their set pressures is essential for precise control over their set values.

Methods Analyzing the structural composition and operational mechanism of pilot-operated surge relief valves, this study investigated the influential factors of their set pressures. It explored influences such as spring force, friction force, sealing structures between the guide valve core and guide valve seat, and pilot valve piston configurations. Specifically, the configurations of springs and pistons were identified as critical influencing factors. Drawing from these insights, the study proposed key measures for ensuring precision in setting the pressures of piloto-perated surge relief valves. Additionally, an experimental system was established to validate the analysis results.

Results When choosing a specific pilot valve spring, enlarging the piston area of the pilot valves within a specified range resulted in enhanced overall accuracy in the set pressures of the pilot-operated surge relief valves. Maintaining a constant piston area and the chosen spring unchanged, a higher set pressure was proportionate to increased set pressure accuracy. With a consistent pilot valve piston area, elevating the spring force broadened the adjustable set pressure range of the pilot-operated surge relief valves. Subsequent experimental verification was conducted using different pilot valve piston and spring configurations. With set pressures held constant, the actual opening pressures of the pilot-operated surge relief valves converged closer to their set pressures as the piston area increased, signaling improved accuracy in the set pressures. Conversely, at constant piston sizes, higher set pressures resulted in closer alignment of the actual valve opening pressures with their set values, reflecting enhanced accuracy in the set pressures.

Conclusion For enhanced accuracy in the set pressures of pilot-operated surge relief valves, it is recommended to select springs and pistons based on their structures and materials, aiming for optimal combinations tailored to specific conditions in engineering applications.