Wedge gate valve take advantage of wedge style dense cover seal up, Can by hand wheel plus carry regulate dense cover paste equal to tightness degree.

楔式闸阀利用楔式密封面密封，可通过手轮加载调节密封面贴合的紧密度。

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We decided to exclude the traditional list of "simple machines, " which includes the lever, pulley, wheel and wedge, since most other tools employ some form of simple machine--a hammer is basically a lever, and an axe is essentially a wedge.

FORBES: Methodology