通径：DN65 - DN250
Sizes: 2¹/₂" – 10" (65 – 250mm)

　　系列709双止回阀总成适用于防止受到污染的水回流进入到饮用水系统中。这种系列可以申请当地有关主管部门的批准用于非健康危害的应用上。系列709特点在于模块化止回阀设计概念，有助于简化日常维护。请咨询当地有关主管部门，了解安装要求。
　　Series 709 Double Check Valve Assemblies are designed to prevent the reverse flow of polluted water from entering into the potable water system. This series can be applied, where approved by the local authority having jurisdiction, on non-health hazard installations. Series 709 features a modular check design concept to facilitate easy maintenance. Check with local jurisdictional authority as to installation requirements.

特点
Features

• 更换青铜阀座
  Replaceable bronze seats
• 在低压降下实现流量最大
  Maximum flow at low pressure drop
• 设计结构简单，简化了日常维护
  Design simplicity for easy maintenance
• 维修时不需要特殊工具
  No special tools required for servicing
• 复位弹簧总成使阀门应用更加安全
  Captured spring assemblies for safety
• 通过垂直向上安装的认可
  Approved for vertical flow up installation

型号
Models

规格说明
Specifications

　　在相关的交叉连接处应该安装一个双止回阀总成，以防止受到污染的水回流到饮用水系统中。应该由当地主管部门检测决定是否需要在不存在高危险情况的地方布置交叉连接。这种阀门应该配置模块化止回阀总成，其阀杆为中心引导。每个止回模块应该配置一个复位弹簧，并且易于从螺栓阀盖板处接触检测或维修。阀座应该是可更换的，并且不需要任何特殊工具。这种总成应该是完整的，包括紧密关闭弹性阀座关闭阀（闸阀），测试旋塞，以及建议配置的一个过滤器。这种总成应该满足美国卫生工程师协会（ASSE）编号1015标准、美国自来水厂协会（AWWA）C510-92标准和加拿大工业标准协会（CSA）B64.5标准的要求，应该通过美国UL文件号EX3185的认证，以及位于美国南加州大学内的美国交叉连接管理和水研究基金会的认证。这种总成应该是美国瓦茨调节阀公司的系列709。
　　A Double Check Valve Assembly shall be installed at referenced cross-connections to prevent the backflow of polluted water into the potable water supply. The cross-connections shall be determined by local inspection authority for use where a high hazard situation does not exist. Valve shall feature modular check assemblies with center stem guiding. Each check module shall have a captured spring and be accessible through a bolted cover plate. Seats shall be replaceable without special tools. It shall be a complete assembly including tight-closing resilient seated shutoff valves, test cocks, and a strainer is recommended. The assembly shall meet the requirements of ASSE No. 1015; AWWA C510-92; CSA B64.5 and UL Classified File No. EX3185. Approved by the Foundation for Cross-Connection Control and Hydraulic Research at the University of Southern California. Assembly shall be a Watts Regulator Company Series 709.

709 OSY

止回总成模块
Check Assembly Module

　　系列709采用模块设计概念，弹簧负载的保持有助于全过程的维护和组装。此外，第一和第二止回模块是相同的，可以互换。
　　Series 709 features a modular design concept which facilitates complete maintenance and assembly by retaining the spring load. Also, the first and second check module are identical and can be interchanged.