When using EZ-TC, close No. 1 and 2 shutoffs and install sight tube using adaptor fitting.
在采用EZ - TC时，关闭1号和2号关闭阀，采用适配器连接件安装观察管。
2
The assembly shall consist of two positive seating check valves located between two resilient seated shutoffs with a hydraulically balanced bypass line and four test cocks .