To surely prevent erroneous water discharge by preventing a valve body from being opened even when pressurized fire extinguishing water is filled rapidly.
When filling and pressurizing the fire extinguishing water from a primary port 14 to a first cylinder chamber 26, a piston 24 is moved to the side of a second cylinder chamber 28 for a second lift amount L2, a plunger 45 is abutted to the closing part of a thermosensitive port 38, the movement of the valve body is prevented from exceeding a first lift amount L1 required for opening, and the erroneous water discharge from a secondary port 18 is prevented. When water filling and pressurization of the second cylinder chamber 28 is completed by an orifice communication path 30, the piston 24 is returned to an initial position. When the thermosensitive port 38 is opened by the pyrolysis of the thermosensitive decomposition part 44, the position regulation of the plunger 45 is released, the piston 24 is moved exceeding the first lift amount L1, and the valve body 34 opens a communication path 32 to discharge water from an open type head 20.
IBARAKI HIROSHI
KUBO MASANOBU
IS SPRINKLER KK