安全閥是一種由進口靜壓開啟的自動泄壓防護裝置,它的功能是：當容器內壓力超過某一定值時,迅速排出一定數量的介質。當容器內的壓力降到允許值時,使容器內壓力始終低于允許壓力的上限,所以安全閥又被稱為壓力容器的最終保護裝置。安全閥根據工作壓力能自動啟閉，一般安裝于封閉系統的設備或管路上保護系統安全。安全閥屬于自動閥類,控制壓力不超過規定值,它的啟閉件受外力作用下處于常閉狀態,超過規定值時自動開啟,介質從中泄出、減壓；當壓力回到正常值時,閥門自動關閉。安全閥類的作用是防止管路或裝置中的介質壓力超過規定數值
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