本标准涵盖了用于处理设备、设备和输送牛奶、奶制品和其他商品的管线上的双座混合阀的卫生方面。这些阀门不能用于将原料奶和奶制品与巴氏杀菌奶、奶制品和其他食品分开。为了符合3-A卫生标准，双座防混阀应符合设计、材料和制造标准以及本标准中引用的适用文件。

This standard covers the sanitary aspects of double-seat mixproof valves used on processing equipment and on equpment and lines which hold or convey milk, milk products, and other comestibles.These valves cannot be used to separate raw milk and milk products from pasteurized milk, milk products, and other comestibles.In order to conform to 3-A Sanitary Standards, double-seat mixproof valves shall conform in design, material and fabrication criteria and the applicable documents referenced in this standard.