1·Four required per backflow preventer.
每个防回流阀需要四个。
2·The backflow preventer must be installed upstream of the regulator.
防倒流装置必须安装在调节阀的上游位置。
3·Installing a backflow preventer in a pit or vault is not recommended.
不建议在坑内或拱顶内安装防回流阀。
4·The relief valve may be serviced while on or off the backflow preventer valve.
可以在防回流阀上维修安全阀，或将其从防回流阀拆卸下来维修。
5·Copper tubing shall not be used on the downstream side of the backflow preventer.
在防回流阀的下游不应该安装铜管。
6·The dual check backflow preventer shall be designed under the ASSE Standard 1024.
这种双止回防回流阀应该按照美国国家标准化组织(ASSE)标准1024进行设计。
7·The backflow preventer must be supported and is not designed to carry full weight of the stand pipe.
防回流阀必须有所支撑， 不能用于承载立管的全部重量。
8·DUAL CHECK VALVE BACKFLOW PREVENTER For low hazard cross-connections. Continuous pressure applications.
双止回防回流阀用于低危险交叉连接。持续压力应用场合。
9·By installing a backflow preventer on any residential water system, you create a closed system that won't accommodate thermal expansion.
通过在任何住宅水系统上安装一个防回流阀，可以形成一个无法适应热膨胀的封闭系统。
10·The Watts 994HMB fire hydrant backflow preventer meters are designed and manufactured to provide long-term service with minimal maintenance.
美国瓦茨994HMB消防栓防回流阀仪表的设计和制造理念在于以 最少的维护提供 最 长的使用 寿命。