7 hr 30 min Even after operators pump water into the primary loop, pressure is still high. The PORV 'backup valve is opened to lower the pressure.
7小时30分钟尽管操作员已将水抽入主回路，但温度仍然很高。减压阀的备用阀门被打开，减少压力。
2
The metal diaphragms act as the seal at the top of the valve. The primary improvement in this generation of valves is the elimination of the spring used to open the valve.
金属横膈膜在阀门的顶部作为密封。这一代阀门的主要的改进是取消了用于开启阀门的弹簧。
3
Primary uses for wrot brass are for ball valve stems and balls, and iron valve stems. a forging grade of brass is used in ball valve bodies and pieces.