Abstract: A liquid delivery nozzle having a circular dispersion plate having an upwardly facing concave side spaced from an output end or orifice of a tube connected to a water supply which may deliver water to the output end at a pressure in the range of 0.3 to 0.5 bars. The water issuing from the output end impacts on the concave side and spreads thereover to fly off the periphery of the plate in the form of drops having little or no vertical velocity component. The major part of the water issuing from the tube is converted into large drops of at least 0.7 mm in diameter. The nozzle can be used in an installation to prevent, suppress or impede the occurrence or development of explosions.