Abstract: In a connection structure for fire extinguishing system piping in which a male piping member is connected to a connection opening portion of a joint by screwing a male thread and a female thread together, the male piping member includes a joint cylinder having a protruding portion that is inserted deeper into the connection opening portion than the female thread. Each male piping member and the connection opening portion includes a step portion. The connection structure further includes an indicator that engages the step portions and in a state in which the male piping member and the connection opening portion are connected together. At least one of the male piping member and the connection opening portion includes an unmountable portion that has an outside diameter different from an inside diameter of the indicator and cannot be engaged by the indicator.

Abstract: A sprinkler head includes a body having a nozzle to be connected to a water supply pipe, the nozzle being provided inside the body; a valve that closes the nozzle in normal times; a pair of frames extending from the body in a direction of water discharge from the nozzle; a main deflector provided at distal ends of the frames; a heat-sensitive disassembling unit provided between the valve and the main deflector; and an assist deflector extending substantially parallel to a virtual plane passing through a center axis of the nozzle and through the frames, the assist deflector being spaced apart from the virtual plane. The heat-sensitive disassembling unit includes a link formed of a plurality of thin plates joined to one another with a low-melting-point alloy, the heat-sensitive disassembling unit further including a bar and a lever that are engaged with the link.

Abstract: There is provided a connection structure for fire extinguishing system piping with which stable sealing performance can be obtained, due to screw engagement, by connection work carried out even by an unskilled worker and with which secure engagement of the connection portion can be confirmed easily. In a connection structure for fire extinguishing system piping in which a male piping member is connected to a connection opening portion of a multi-port joint T by screwing a male thread and a female thread together, the male piping member includes a joint cylinder having a protruding portion that is inserted deeper into the connection opening portion than the female thread. The male piping member also includes the sealing members and that seal the engagement portion between the male thread and the female thread to prevent water leakage into the inside of the connection opening portion. The male piping member includes a step portion, and the connection opening portion includes a step portion.

Abstract: A sprinkler head cover includes: a tubular housing connected to a sprinkler head; a cover plate installed below the housing; and a fusible alloy interposed between the housing and the cover plate. The fusible alloy is constituted of a solder piece having a predetermined shape. The fusible alloy is joined to the housing or the cover plate via an adhesive member installed on a surface of the fusible alloy.