automatic open-close sprinkler是什么意思

用法例句

The design and lectotype of circulating pump, automatic return water switch valve, expansion tank and atmospheric connection pipe in atmospheric hot water heating boiler room are discussed.

对常压热水供热锅炉房的循环泵、回水自动启闭阀、膨胀水箱、大气连通管的设计选型进行了探讨。