Full-open opening mechanism of expansion gate valve with back seal synchronous gate plate

The utility model relates to the technical field of expansion type parallel double-gate-plate gate valves, in particular to an expansion gate valve full-open opening mechanism with a back seal synchronous gate plate, which comprises a valve cover, a valve rod, a gate plate large blade connected with the valve rod, and a gate plate small blade connected with the gate plate large blade, a limiting compensation assembly used for conducting limiting compensation on the gate plate small blades is arranged between the gate plate small blades and the valve deck. And a sealing piece for upper sealing is arranged between the valve rod and the valve cover. The device has the effect that the upper sealing function and gate plate small blade limiting are guaranteed at the same time, and therefore gate plate opening is completed. 本申请涉及膨胀式平行双闸板闸阀的技术领域，尤其是涉及一种膨胀闸阀带倒密封同步闸板全开撑开机构，其包括阀盖、阀杆与阀杆连接的闸板大叶、与闸板大叶连接的闸板小叶；所述闸板小叶和阀盖之间设置有用于将闸板小叶进行限位补偿的限位补偿组件；阀杆和阀盖之间设置有用于上密封的密封件。本申请具有同时保证上密封功能以及闸板小叶限位从而完成闸板撑开的效果。