
Delavan 0.85GPH, 70A nozzle
This Delavan nozzle is a precision component that atomises fuel oil into a fine spray for complete combustion. In an oil burner, the nozzle is fitted into the combustion head and receives pressurised fuel from the pump. The spray pattern and droplet size directly determine how the flame sits relative to the air stream, so the nozzle must be matched to the burner’s design. Nozzles of this type are selected by three parameters: flow rate (in US gallons per hour at the standard reference pressure), spray angle, and spray pattern (hollow cone, solid cone, or semi-solid cone). The flow rate controls the fuel input and therefore the burner output; the angle and pattern govern flame shape and stability. This specific nozzle carries a rating of 0.85 GPH and a 70A designation. When replacing a nozzle, always verify that all three parameters match the burner data plate. Using a nozzle with the correct flow but wrong pattern can cause sooting, pulsation, or ignition failure. The nozzle is a consumable item and should be replaced as part of routine burner service. The thread is standard for this class of part; ensure the sealing washer is renewed on installation.