灌溉设备.化学灌溉安全装置.第2部分：DN75（3“）至DN350（14”）的化学灌溉阀组件

[中文适用范围]： ISO 13693 的这一部分规定了金属阀体化学阀门的结构和性能要求以及测试方法，其水温不超过 50 °C，可能含有农业中使用的类型和浓度的肥料和化学品。 该阀门旨在防止因背压或反虹吸作用引起的回流。 它不适用于饮用水系统。 不要将其与其他形式的防回流装置混淆，包括压力真空断路器、双止回阀、减压区域阀或鹅颈环。 ISO 13693 的这一部分规定了化学阀组件的最低设计、结构和性能测试要求。 该组件由以下部件组成： ——阀体，其中安装有弹簧止回阀，密封面上有弹性盘盖； ——位于止回阀上游的组合排气/真空安全阀； ——位于止回阀上游的低压排水阀； ——检查口的位置允许目视和手动检查阀门工作部件。 [外文原描述]： ISO 13693-2:2015 specifies the construction and performance requirement and test methods for metal-bodied chemigation valves with water at temperatures not exceeding 50 °C, which might contain fertilizers and chemicals of the types and concentration used in agriculture. The valve is designed to prohibit backflow caused by either back pressure or back siphonage. It is not designed for use in potable water systems. It is not to be confused with other forms of backflow prevention devices including pressure vacuum breakers, double check valves, reduced pressure zone valves, or goose neck loops. ISO 13693-2:2015 specifies the minimum design, construction, and performance testing requirements for the chemigation valve assembly. The assembly consists of the following components: ? a valve body into which a spring-loaded check valve is mounted with a resilient disk cover on the sealing surface; a combination air release/vacuum relief valve located upstream of the check valve; a low pressure drain valve located upstream of the check valve; an inspection port located so as to permit visual and manual inspection of the valve working components.