Delavan 8.00GPH, 45W nozzle

This catalogue article is 345.892.273, and the manufacturer code is 00800-45W7 (also listed as 345.892.273). It is a Delavan oil nozzle designated 8.00GPH, 45W. Oil nozzles of this type are precision consumable parts that atomise fuel oil into a fine spray cone, allowing complete combustion in the burner head. The three parameters that define a nozzle—flow rate (in GPH or kg/h at the reference pressure), spray angle, and spray pattern (hollow, solid, or semi-solid)—must all match the burner data plate. A nozzle with the correct flow rate but the wrong pattern can cause sooting, flame pulsation, or unstable ignition, so all three must be verified before installation. In a pressure-jet oil burner, this nozzle sits at the end of the oil supply line, downstream of the oil pump and solenoid valve. The pump delivers fuel at high pressure; the solenoid valve controls the start and stop of flow. Where a preheater is fitted, it heats the oil before it reaches the nozzle to improve atomisation. The nozzle is a wearing part and should be replaced at the intervals specified by the burner manufacturer—typically as part of annual servicing. When replacing, confirm that the replacement nozzle carries the same flow rating, spray angle, and spray pattern as the original. The thread size must also match; most domestic oil nozzles use a standard 1/8 in BSPT thread, but always verify against the burner head.