Monarch Oil nozzle 1.35GPH / 45R

This is an oil nozzle with a flow rate of 1.35 GPH, a 45 ° spray angle and an R spray pattern. It is used to atomise fuel oil into a fine spray for combustion in an oil burner. The 45 ° angle defines the shape of the spray cone, and the R pattern defines the distribution of fuel within that cone. The rated flow of 1.35 GPH is stated at a reference pressure, so the nozzle meters fuel according to the pressure it is supplied with.

Nozzles of this type are selected by matching the flow rate, spray angle and spray pattern to the burner and combustion chamber, and by matching the thread and body form to the nozzle holder. Mounting forms differ between manufacturers, so the seat, thread and overall length must be compared with the part being replaced before ordering. The rated flow is quoted at a reference pressure, so the pump pressure setting must correspond to the value the burner was set up for.

Nozzles of this kind commonly fail by clogging or by wear of the orifice, which changes the flow rate and the spray shape. The equipment may then show a poor flame, smoke, soot deposits, delayed ignition or a flame that will not hold. Checking the spray pattern, the flow rate and the strainer, and comparing the pump pressure with the burner setting, is the usual way to confirm the fault.