The Research On Seat Sealing Of LNG Top Entry Cryogenic Trunnion Mounted Ball Valve

The development of the LNG clean energy industry, synchronized drive the demand of the valve used in LNG industry, And The performance reqcuirements for LNG cryogenic ball valve are constantly improved based on the high standard demand of the users. But there is very few manufacturering experience and test data on LNG cryogenic ball in china. So, research on LNG cryogenic ball valve especially on seat sealing has great practical significance.This article located in research of seat sealing for top entry trunnion mounted ball valve in LNG condition, connected the design line of related seat sealing component of valve and then discussed the sealing of the soft sealing trunnion mounted ball valve. Meanwhile the article aimed at the requirement that LNG valves, Researched valve’s online maintenance function.The article first analyzes the property, preparation and storage of the LNG, application of the valve in the LNG plant. These analyses provide a basis for material selection and structure design of the valve. Then analyze the design requirements of LNG cryogenic ball valves from design and manufacturing standards, material selection and structure design. Grasp more comprehensive design information and requirements of LNG cryogenic ball valves.Thereupon, do more in-depth analyze and research on metal materials, non-metallic materials, sealing surface structure and related elements of of seat sealing for top entry trunnion mounted ball valve in LNG condition. Get the following information from experiments: performance parameters of PCTFE, relationship between spring force and deformation on different structure of Lipseal spring, the change of ferrite content in the weld seam of austenitic stainless steel before and after cryogenic treatment. Provide the optimization of pressure balance structure and on line maintenance structure. Provide good foundation for solving the key difficulty of LNG ball valve.Finally, use the prototype of trunnion mounted soft sealing ball valve as the carrier, design and manufacture typical ball valve for LNG conditions, Using ANSYS software to analyze the valve body strength, furthermore verify and feedback design effect through testing. The design problem that feedbacked from the manufacturing process has being improved and optimized, verify it again through testing. Verify the sealing performance of the valve and improve the improvement program of the valve online maintenance. Eventually improve the design of top entry trunnion mounted ball valve in LNG condition. Verify the research results.