Abstract: The present invention provides a spray device for fire fighting, which sprays atomized water to extinguish a fire. The spray device (100) includes an upper body (10), a lower body (20) which is removably coupled to the upper body (10), a nozzle tip (30) which has a swirl (39) therein and is removably inserted into each nozzle tip hole (22) of the lower body (20), and an interposition unit (40). The spray device (100) further includes an inclined surface (16), a tightening contact surface (19-1) provided on an outer surface of a circular head part (19) of the upper body (10), a working groove (26) to provide an internal thread (25) on the lower body (20), and a hemispherical mesh (42) which has a convex shape and is provided in a chamber (41) defined at a center position between the upper body (10) and the lower body (20).

Abstract: Disclosed is a safety valve installed in a tank of a vessel carrying oil or chemical substance to discharge supersaturated gas produced in the tank and to adjust an internal pressure to a normal level when a negative pressure is produced in the tank. The valve comprises a lower body; an upper body mounted onto the lower body; a valve stem extended from the upper body to the lower body; and a disc provided on the valve stem and positioned between the upper and lower body to shut out a communication between the upper and lower body. The disc has a groove on an underside thereof, with a protruded portion being formed along an edge of the disc, a Teflon bushing is interposed between the disc and the valve stem, and the disc has a large diameter than an internal diameter of the lower body.