- Flow Switch
A water flow switch or water flow switch in an automatic fire sprinkler system or less often a fire hydrant system is an electro-mechanical alarm initiating device that has been designed to detect the flow of water through a pipe.
A water flow switch is typically installed in the water supply (above an alarm valve) or in a branch of an automatic fire sprinkler system or fire hydrant system and is used to detect the flow of water indicating an alarm condition.