Delavan 45.00GPH, 45B nozzle

This article is a Delavan oil nozzle, catalogue number 345.892.241, with manufacturer codes 04500-45B0 and 345.892.241, listed under the 45.00GPH, 45B designation. It belongs to the class of precision consumable parts that atomise fuel oil into a fine spray cone for complete combustion. In an oil burner, the nozzle is mounted at the end of the oil gun and receives pressurised fuel from the pump. It is a wear item that requires periodic replacement to maintain flame quality and efficiency. Parts of this type are selected by three parameters: flow rate (here stated as 45.00 GPH, referenced to a standard pressure), spray angle, and spray pattern. The pattern can be hollow, solid, or semi-solid. All three must match the burner manufacturer’s specification, typically given on the burner data plate. Using a nozzle with the correct flow but incorrect pattern can cause sooting, pulsation, or unstable ignition. The thread size is standardised for the burner fitting, but always verify compatibility with the existing nozzle before installation. In the oil system, the nozzle works together with the oil pump and solenoid valve; on cold-start systems, a preheater may also be present. Due to the precision of the orifice and the effects of wear from high-pressure flow, replacing this component with an identical specification is essential for reliable operation.