Buse Monarch 1.20GPH, 45R

This is an oil nozzle from Monarch, specified as 1.20 GPH, 45R. Oil nozzles are precision consumable parts that atomise fuel oil into a fine spray so that it can burn completely. The nozzle sits at the end of the oil supply line inside the burner’s combustion head, where it works with the oil pump and the solenoid valve to deliver a controlled fuel flow. For any oil burner, selecting the correct nozzle requires matching the flow rate, spray angle, and spray pattern to the burner’s data plate. The flow rate (given in GPH at the reference pressure) determines the fuel input, while the spray angle and pattern shape the flame to fit the combustion head and blast tube. A nozzle with the correct rating but an unsuitable angle or pattern can lead to sooting, pulsation, unstable ignition, or incomplete burn. Therefore, all three parameters must be verified before a replacement. When handling this type of nozzle, avoid touching the orifice or contaminating the filter screen. The thread is a standard size for most domestic and light commercial oil burners, but always check compatibility with the burner manufacturer’s specification. The Monarch brand is commonly used in this category; parts of this class are typically replaced annually or as part of routine service.