Steinen (0984S21) 3.00GPH, buse 45S

This is an oil nozzle from Steinen, identified by manufacturer code 0984S21 and catalogue article 908.892.100. The nozzle is a precision consumable part that atomises fuel oil into a fine spray cone, enabling complete combustion in the burner. The designation indicates a flow rate of 3.00 GPH at the reference pressure and a 45-degree spray angle with a solid (S) pattern, though the specific rating and pattern must be verified against the burner data plate. Parts of this type are selected by flow rate (in GPH or kg/h at the reference pressure), spray angle (commonly 30–80 degrees), spray pattern (hollow, solid, or semi-solid), and thread size. All three parameters—rating, angle, and pattern—must match the burner manufacturer’s specification. Using a nozzle with the correct flow rate but the wrong pattern can cause sooting, flame pulsation, or unstable ignition. For replacement, check the existing nozzle’s markings and confirm compatibility with the burner’s combustion head and pump pressure setting. The nozzle sits between the oil pump and the combustion head, working with the pump solenoid and, if present, the preheater.