An Optimization Method for Valve Seat Contour to Improve the Sealing Performance of Cryogenic Butterfly Valve

Abstract Triple-offset butterfly valves are manufactured under standard temperature conditions. During cryogenic service, critical sealing structures undergo uneven deformation due to thermal contraction. This leads to insufficient sealing pressure, which may result in seal failure. To enhance the cryogenic sealing performance of triple-offset butterfly valves, this study introduces an iterative method for optimizing the valve seat's outer contour. A coupled thermal-structural finite element analysis is first performed to evaluate the sealing behavior under cryogenic conditions. Based on the contact stress distribution and deformation of key components, targeted contour modifications are applied. Finally, the sealing performance of the optimized valve is evaluated through cryogenic temperature testing. After the optimization of the valve seat structure, the minimum contact stress in the sealing weak area increased from 4.57 MPa to 8.08 MPa, resulting in a substantial improvement in the overall sealing performance. Cryogenic testing results indicated that the optimized butterfly valve reduced leakage by 44%, meeting the practical sealing requirements of butterfly valves under cryogenic temperature conditions and further validating the effectiveness and applicability of the proposed optimization approach in improving sealing performance. This study proposes an optimization method for seal structures to enhance the sealing performance of cryogenic butterfly valves, offering valuable insights for the design of other cryogenic sealing components.