Reliability analysis of stainless steel ball valve

With the continuous development of the national economy, the demand for high-efficiency and low-cost stainless steel ball valves in hydropower, petrochemical and other industries is increasing, and the performance requirements for stainless steel ball valves are also getting higher and higher. Over the years, the structural optimization of stainless steel ball valves can only rely on engineering experience. Due to the complex structure of stainless steel ball valves, there will be concentrated stress and uncoordinated deformation, resulting in reduced service life and leakage of stainless steel ball valves. The main research on stainless steel ball valves is as follows:
1. A finite element analysis model of the structure of stainless steel ball valve body is established, the strength and deformation of the valve and valve body structure are analyzed, the size and distribution of the equivalent forces between the valve and the valve body are obtained, and the weak links of the structure are found. 2. Taking the quality and stiffness of the stainless steel ball valve body as the constraints, the maximum stress and maximum displacement as the target function, the basic size of the stainless steel ball valve body as the design variable, combined with sensitivity analysis and Pareto multi-objective optimization, reasonable reinforcement structure size and position are obtained to improve the ball valve. The overall stress distribution makes its distribution more uniform, which improves the overall structural safety and economy of the ball valve. 3. The reliability analysis of the structure of the improved stainless steel ball valve body is carried out, the reliability parameters such as life, damage and safety coefficient are obtained, the parts that are prone to fatigue failure are found, and the safety of the large-caliber ball valve is evaluated. The results show that the improved valve and valve body are safe and reliable under working pressure. Meet the design requirements.