Abstract: A spray nozzle, especially for spraying water in fire prevention systems, has a housing in which there is a vortex chamber into which a first channel into which a first channel for supplying water opens essentially tangentially at a distance from the axis of the vortex and which has a first outlet orifice coaxial with the axis of the vortex. The spray nozzle also has a second outlet orifice arranged inside the vortex chamber so it is coaxial with the first outlet orifice and is located at the end of a second channel that is coaxial with the axis of the vortex. The second channel has an enlarged area upstream from the second outlet orifice, where the cross-sectional area at right angles to the axis of the channel increases in the direction of flow. furthermore, the cross-sectional area of the second channel at right angles to the axis of the channel does not decrease further downstream from the enlargement as seen in the direction of flow.

Abstract: A fire-fighting system, which includes a nozzle housing having a turbulence chamber with a nozzle aperture communicating with the turbulence chamber and a temperature responsive compressive element which gives way at a specified temperature, and which compressive element and a sealing unit for the nozzle are held in place against the nozzle by a spring under compression which is released when the compression element gives way at a specified temperature.