Seismic Analysis and Calculation of LNG Cryogenic Ball Valve

Cryogenic ball valves are widely applied in low-temperature engineering fields such as LNG transportation and serve as key equipment for the stable operation of LNG receiving terminals. To guarantee reliable operation of the valve under severe seismic conditions, this paper designs a top-entry cryogenic ball valve structure. A simulation model is established to examine whether the structural strength of the valve meets design requirements under low-temperature operating conditions. Low-temperature seismic simulation calculations are performed, and the calculation results are analyzed and evaluated. The research results indicate that the proposed seismic simulation model can simulate and calculate the temperature field distribution of each valve component, and the proposed stress evaluation method can effectively assess whether the valve structure complies with the stress criteria for different operating grades （Grade O, A, B, C, D）. Simulation results show that the designed valve structure can satisfy the stress evaluation criteria for Grade O design conditions even under the most severe Grade D accident conditions. This study provides references for the seismic calculation and stress evaluation of cryogenic valves, and has certain guiding significance for subsequent research.