Delavan 0.75GPH, 45A (1) Düse

This is a Delavan oil nozzle rated at 0.75 GPH with a 45A designation. It belongs to the category of oil nozzles, which are precision consumable parts that atomise fuel oil into a fine spray for complete combustion. The nozzle sits between the oil pump and the combustion head; when the burner control energises the pump solenoid, pressurised oil is delivered to the nozzle, where it is forced through an orifice to create a conical spray pattern. For any oil nozzle, the flow rate (in GPH, typically at 100 psi reference pressure), spray angle, and spray pattern together determine how the flame sits in the combustion head. Parts of this type are selected by matching all three parameters exactly to the burner data plate. The 45A code in this nozzle’s name indicates its spray angle and pattern designation, though the exact meaning of the letter (hollow, solid or semi-solid cone) must be verified against the manufacturer’s specification or existing part. Using a nozzle with the correct flow rate but wrong pattern or angle can cause sooting, pulsation, or unstable ignition. When replacing an oil nozzle, always confirm the thread size and ensure the new nozzle matches the old one in GPH rating, angle and pattern. Because nozzles wear over time—carbon deposits or orifice enlargement can degrade atomisation—routine replacement is recommended as part of burner service. No additional compatibility claims are made for this specific article beyond the data provided.