High pressure nozzle and method for the manufacture of a high pressure nozzle

A high pressure nozzle for descaling steel products for installation in and communication with a liquid supply channel defining a central longitudinal axis and having an upstream end wherein liquid enters the supply channel and a downstream end where liquid is discharged from the supply channel, said nozzle comprising a jet director defining at least one guide surface disposed to guide flow of liquid through said nozzle and a central area disposed radially inwardly of said guide surface and coextensive with the central longitudinal axis of the supply channel, said central area being unobstructed to permit the flow of liquid through said central area such that liquid flows through said jet director along said guide surface and through said central area from the upstream end to the downstream end of the supply channel, said nozzle further including a cylindrical portion disposed downstream of said jet director and defining a channel therein, a first part of said channel disposed immediately adjacent and downstream of said jet director being tapered to restrict the flow of liquid as same flows in an upstream to downstream direction through said first part, said channel including a second part disposed downstream of said first part, said second part having a constant diameter along an entire longitudinal extent of said second part which is substantially equal to a diameter of a downstream end of said first part.