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閥桿軸心同時偏離碟片中心及本體中心，且閥座回轉(zhuǎn)軸線與閥體通道軸線有一定角度的，稱為三偏心蝶閥，這種設(shè)計使得蝶板啟閉時幾乎零摩擦，大大延長密封副的使用壽命。

A three eccentric butterfly valve is a type of valve in which the valve stem axis deviates from both the center of the disc and the center of the body, and the valve seat rotation axis has a certain angle with the valve body channel axis. This design ensures almost zero friction when the butterfly plate is opened and closed, greatly extending the service life of the sealing pair.