1.
A check valve may be required ahead of the backflow preventer.
此时在防回流阀前面可能需要安装一个止回阀。
2.
Slowly open upstream shutoff and allow the backflow preventer to fill slowly.
慢慢开启上游关闭阀，让防回流阀慢慢注水。
3.
The system should be flushed before the backflow valve is installed.
在安装回流阀之前系统应该进行冲刷。
4.
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。
5.
For use with backflow preventer test cocks to protect from damage.
用于防回流阀测试旋塞，防止受到破坏。
6.
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。
7.
To avoid this discharge, install a spring-loaded, rubber seated check valve ahead of the backflow assembly.
为了避免这种排放，要在防回流阀总成前面安装一个弹簧驱动、橡胶阀座的止回阀。
8.
After removing the first check from the backflow valve body, place on a flat surface with the coil spring facing up.
从防回流阀阀体上拆卸第一止回阀后，要使螺旋弹簧面朝上放在平面上。
9.
The 909 Series backflow preventer is designed so that the critical level of the relief valve is positioned below the first check.
909系列防回流阀的设计结构使得安全阀的临界水位位于第一止回阀下方。
10.
The shutoff valve with the test cock is to be mounted on the inlet side of the backflow preventer.
带测试旋塞的关闭阀安装在防回流阀的进口一侧。
11.
This is a gate valve (check valve, butterfly valve, cut-off valve, magnetic valve, remote valve, relief valve, throttle valve, cock).
这是一个闸阀（止回阀、蝶阀、切断阀、电磁阀、遥控阀、安全阀、节流阀、旋塞）。
12.
Check valves or as a one-way valve. For the hydraulic system to prevent reverse flow of oil flow.
单向阀又称止回阀或逆止阀。用于液压系统中防止油流反向流动。
13.
Use check valves to prevent reverse flow in to the cylinder.
使用止回阀，防止回流入钢瓶。
14.
Use a check valve to prevent reverse flow into the cylinder.
采用止回阀，防止回流入钢瓶。
15.
Globe pattern stop-check valves can be used in horizontal piperuns with the stem straight up.
截止阀类型的节流止回阀可以用在水平管道上，阀杆垂直向上。
16.
Check Valve 1;Check Valve 2;Check Valve 3;Screw-down
止回阀 1;止回阀 2;止回阀 3;旋拧阀
17.
Purpose: To test check valves for tightness in the direction of flow.
目的：检测止回阀在流向上的紧固性。
18.
Requirement: Valve must be tight against reverse flow.
要求：这种阀门对于回流必须密封紧密。