Abstract: A firefighting nozzle is provided with a relief valve assembly that opens to discharge a fine spray or “curtain” of liquid extending 360° around the nozzle, thus cooling off the nozzle operator and the surrounding area, while at the same preventing dangerous pressure build-up in the nozzle. In a preferred embodiment, the relief valve assembly comprises a housing having a substantially cylindrical side wall defining a bore. A tubular sleeve divides the bore into two parts: a cylindrical inner passage defining the primary flow path for liquid traveling through the nozzle; and an annular space defining a valve chamber. A plurality of relief ports is formed in a 360° degree pattern around the side wall of housing, each relief port defining a secondary flow path extending substantially perpendicularly to the primary flow path. An annular plug is mounted for sliding movement on the inner sleeve, from a first position blocking the relief ports to a second position allowing flow therethrough.

Abstract: A firefighting nozzle is provided with a relief valve assembly that opens to discharge a fine spray or “curtain” of liquid extending 360° around the nozzle, thus cooling off the nozzle operator and the surrounding area, while at the same preventing dangerous pressure build-up in the nozzle. In a preferred embodiment, the relief valve assembly comprises a housing having a substantially cylindrical side wall defining a bore. A tubular sleeve divides the bore into two parts: a cylindrical inner passage defining the primary flow path for liquid traveling through the nozzle; and an annular space defining a valve chamber. A plurality of relief ports is formed in a 360° degree pattern around the side wall of housing, each relief port defining a secondary flow path extending substantially perpendicularly to the primary flow path. An annular plug is mounted for sliding movement on the inner sleeve, from a first position blocking the relief ports to a second position allowing flow therethrough.