To credibly spray water when a fire occurs by remotely monitoring whether a test gate valve is fully and certainly opened.

The test gate valve 14 includes an open/close detection switch 46 that turns on a switch contact at a fully opened position and turns off the switch contact at a closed position deviated from the fully opened position. The switch contact of the open/close detection switch 46 is inserted into and connected to a signal line 44 extending from a fire prevention receiving panel 36 connected to a pressure switch 28. When the test gate valve 14 is at the closed position deviated from the fully opened position and the switch contact of the open/close detection switch 46 is turned off, the fire prevention receiving panel 36 detects the disconnection of the signal line and informs that the test gate valve 14 is not at the fully opened position.