Analysis of Factors Influencing Y-Ring Sealing Under Ultra-High-Pressure, High-Temperature, and Low-Temperature Conditions

Abstract

To study the factors affecting the sealing performance of a Y-shaped sealing ring at the stem of a 140-MPa cage throttle valve under −46 °C, 25 °C, and 180 °C operating conditions, uniaxial tensile tests were conducted on polytetrafluoroethylene (PTFE) and its modified materials. Finite element simulation software was then used to perform a simulation study of the Y-shaped sealing ring. The finite element simulation software was used to perform a sensitivity analysis on the five most critical parameters of the Y-shaped sealing ring and to perform dimensional optimization by using the multi-island genetic algorithm. The results show that compared with 25 °C, under a 180 °C condition, the contact stress at both ends of the sealing lip decreases when the valve stem moves upward. Under the condition of −46 °C, the contact stress at the sealing lip increases when the valve stem goes down, the contact stress at both ends of the sealing lip decreases when the valve stem goes up; and the impact of the stem movement speed on the maximum value of the Y-shaped sealing ring contact stress is small. The design dimensions that have the greatest influence on the maximum von Mises stress and the maximum contact stress of the inner lip of the Y-seal during stem movement are the width and the tip height of the lip, respectively. The optimum values of the design variables are determined and the feasibility of the theoretical design is verified by testing.