系列007DCDA双止回阀检测总成专用于符合自来水主管部门非健康危害密封要求的应用场合。这种总成强制性防止消防系统流体介质的倒流(回流)，如甘油润湿剂，积滞水和非饮用水，防止这些流体介质泵吸或虹吸进饮用水管道。
　　Series 007DCDA Double Check Detector Assemblies are designed exclusively for use in accordance with water utility authority on non-health hazard containment requirements. It is mandatory to prevent the reverse flow of fire protection system substances, i.e., glycerin wetting agents, stagnant water and water of non-potable quality from being pumped or siphoned into the potable water line.
　　优点：检测泄漏……特别重视无法接受水介质所可能造成的损失；配置一个仪表使得自来水公司能够：
　　Benefits: Detects leaks…with emphasis on the cost of unaccountable water; incorporates a meter which allows the water utility to:

• 检测地下泄漏，这些泄漏造成的浪费日积月累将产生很高的年使用成本。
  detect underground leaks that historically create great annual cost due to waste.
• 对于未经认可的使用提供检测点。有利于找出非法泄漏或偷用。
  provide a detection point for unauthorized use. It can help locate illegal taps.

　　模块化止回阀结构简化了总成的维护和维修。所有通径都标准配置弹性阀座OSY关闭阀和16 x 19mm仪表。
　　Modular check design concept facilitates maintenance and assembly access. All sizes are standardly equipped with resilient seated OSY shutoff valves and ⁵/₈" x ³/₄" (16 x 19mm) meter.

特点
Features

• 熔融环氧树脂涂敷铸铁一件式DN65 - DN80
  Fused epoxy coated cast iron unibody 2¹/₂" – 3" (65 – 76mm)
• 可更换青铜阀座
  Replaceable bronze seats
• 在低压降下实现最大流量
  Maximum flow at low pressure drop
• 结构紧凑，易于安装
  Compact for ease of installation
• 结构简单，易于维护
  Design simplicity for easy maintenance
• 维修时不需要特制的工具
  No special tools required for servicing
• 青铜阀体球阀测试旋塞
  Bronze body ball valve test cocks
• 模块式弹簧负载止回阀
  Modular spring loaded checks
• 配置青铜16 x 19mm仪表
  Furnished with bronze ⁵/₈" x ³/₄" (16 x 19mm) meter

规格说明
Specifications

　　这种双止回阀检测总成应该安装在与饮用水管道连接的消防系统上。其危险程度由当地主管部门认定。防回流阀应该是一个完整的总成，包括UL认证的弹性阀座OSY关闭阀和四个测试旋塞。位于防回流阀上的测试旋塞应该安装在阀门的顶部，避免产生空间问题并有助于从总成内排出空气。这种总成应该包括两个独立运作的模块提升式止回阀。这些止回阀应该配置归位弹簧和可更换阀座。止回阀应该是双重引导，都沿着止回阀模块外缘，并穿过中心阀杆总成。阀座应该是可更换的，更换是不需要使用特殊的工具。阀座结构应该采用联锁卡口笼，不能使用螺纹阀座或者阀座螺丝。应该通过唯一的顶部开口盖进入止回阀总成内部。阀盖应该采用不锈钢螺栓紧固。在需要FM认证的设施上应该采用FM认证的OSY弹性阀座关闭阀。这种总成应该包括一个由通过认证的防回流阀和水表构成的辅助旁路管道。这个总成应该通过美国安全工程师协会标准1048，美国自来水厂协会标准C510-92和加拿大标准协会B64.5得认证。通过位于美国南加州大学内的美国交叉连接控制和水力研究基金会的认证。这个总成应该是美国瓦茨调节阀公司的系列007DCDA.
　　A Double Check Detector Assembly shall be installed on fire protection systems when connected to a potable water supply. Degree of hazard present is determined by the local authority having jurisdiction. The backflow preventer shall be a complete assembly including UL listed resilient seated OSY shutoff valves and four test cocks. The test cocks located on the backflow preventer shall be mounted at the top of the valve to reduce clearance problems and to assist in the evacuation of air from the assembly. The assembly shall consist of two independently operating modular poppet-type check valves. The check valves shall utilize captured springs and shall have replaceable seats. The checks shall be double-guided, both along the outside edge of the check module and through the center stem assembly. The seats shall be replaceable without the use of special tools. Seat retention shall be done by the use of an interlocking bayonet-style cage and the use of threaded seats or seat screws is prohibited. Access to the internal check assemblies shall be via a single top entry cover. The cover shall be securely held in place by stainless steel bolts. Where applicable the unit shall be FM approved with FM approved OSY resilient seated shutoff valves. The assembly shall include an auxiliary bypass line consisting of an approved backflow preventer and water meter. The assembly shall be listed or approved under the requirements of ASSE Std. 1048, AWWA Std. C510-92 and CSA B64.5. Approved by the Foundation for Cross-Connection Control and Hydraulic Research at the University of Southern California. The assembly shall be a Watts Regulator Company Series 007DCDA.

DN50
007DCDA OSY
2" (50mm)
007DCDA OSY

DN80
007DCDA OSY
3" (80mm)
007DCDAOSY