Fire hydrant,the official name for the fire hydrant,a fixed fire facilities,the main role is to control the combustibles,isolated combustion-supporting material,eliminating the fire source. Sub-indoor fire hydrant and outdoor fire hydrant. Fire system includes outdoor fire hydrant system,indoor fire hydrant system,fire extinguisher system,and some will have automatic sprinkler system,water cannon system,gas fire extinguishing system,fire detection system,water mist system. Fire hydrant mainly for fire engines from the municipal water supply network or outdoor fire water pipe network to implement fire fighting,can also be directly connected to water,water gun fire. Therefore,the indoor and outdoor fire hydrant system is also an important fire fighting facilities one.