Delavan 9.50GPH, 45B nozzle

This is an oil nozzle from Delavan, catalogue article 345.892.280, also identified by manufacturer code 00950-45B7. The name gives a flow rate of 9.50 GPH and a spray angle of 45 degrees with a B pattern (the pattern letter indicates whether the spray is hollow, solid or semi-solid). The exact meaning of the pattern designation depends on the manufacturer's coding, but for any oil nozzle the flow rate, angle and pattern together determine how the fuel cone fits the combustion head of the burner. Parts of this type are precision consumables that atomise fuel oil into a fine spray so that it burns completely. A nozzle with the correct flow rating but the wrong spray angle or pattern can cause sooting, pulsation or unstable ignition, so all three parameters must be checked against the burner data plate when selecting a replacement. The nozzle is mounted on the oil pump line, downstream of the pump and the solenoid valve. In a typical oil burner sequence the pump pressurises the fuel, the solenoid opens, and the nozzle atomises the oil into the air stream from the fan. The flow rate of the nozzle is stated at the reference pressure used by the manufacturer; exact performance depends on operating pressure. When replacing a nozzle of this class, confirm the thread type as well as the rating, angle and pattern. No additional properties are provided for this specific article beyond its name and codes.