| 摘要 |
This invention relates to an in-line back flow preventer valve for fluid supply lines of the reduced pressure zone type. The valve body has an inlet means and a discharge means for liquid flow therethrough. A first chamber, within the valve body, is in liquid communication with the valve inlet, with the first chamber having at least one outlet positioned in the periphery thereof. At the outer periphery of the first chamber is a first flexible member which is adapted to seal the peripheral outlet through elastic pressure under the static or back flow pressure condition within the valve. A second chamber commonly referred to as a reduced pressure zone is positioned outside the first chamber and has at least one outlet in the periphery thereof. Mounted at the outer periphery of the second chamber is a second flexible member adapted to seal the peripheral opening through elastic pressure when the valve is under the back flow or static pressure condition. The second flexible member is further adapted to allow liquid flow communication between the second chamber and the discharge means through the peripheral outlet during forward liquid flow within the valve.
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