🔍 Key Concepts

• Boiler burner register assembly – what each component (register, diffuser, atomizer, distance piece) does • How air and fuel mixing is physically adjusted in an oil burner front • Which parts control air quantity/flow versus nozzle/atomizer position

💭 Think About

• Think about what a distance piece most likely changes: does it shift the position of a part, or change the total amount of air? • Which component in the choices is most sensitive to its exact location inside the burner tile for good combustion? • Ask yourself: which options talk about position of a component, and which talk about flow rate or quantity? Which seems more related to a spacer or distance piece?

✅ Before You Answer

• Identify which choice refers to positioning rather than total quantities or percentages of air and fuel • Recall that the register vanes and cones mainly regulate how much primary vs secondary air passes, not usually with a distance spacer • Confirm which burner part needs correct set-back distance from the burner throat for proper air–fuel mixing