A nozzle is a device designed to control the direction or characteristics of a fluid flow as it exits an enclosed chamber or pipe. It is typically a pipe or tube of varying cross-sectional area. Different types of extinguishing systems use different types of nozzles, allowing the best possible extinguishing effect to be achieved.
High-pressure gas is produced beneath the nozzle when the system discharges. There must be no obstruction under the nozzle at any time.