OFTEC Oil Burner Types and Operation

Question 1

Which type of oil burner atomises fuel by forcing it through a nozzle under high pressure?

Accepted Answer

Pressure jet burner

Answer

A pressure jet burner uses a pump to force oil through a fine nozzle at high pressure (typically 7-10 bar), creating a spray pattern that mixes with air for efficient combustion.

Question 2

What is the typical fuel pump pressure for a domestic pressure jet oil burner?

Accepted Answer

7-10 bar

Answer

Domestic pressure jet burners typically operate at 7-10 bar pump pressure. This pressure is sufficient to atomise the kerosene through the nozzle for clean combustion.

Question 3

What grade of oil is most commonly used in UK domestic oil-fired heating systems?

Accepted Answer

28-second kerosene (Class C2)

Answer

28-second kerosene (BS 2869 Class C2) is the standard fuel for domestic oil heating in the UK. It is cleaner burning than gas oil and suitable for pressure jet and vaporising burners.

Question 4

What is the primary function of the photocell in a pressure jet oil burner?

Accepted Answer

To detect the presence of a flame

Answer

The photocell (flame sensor) detects UV or visible light from the burner flame. If no flame is detected within the lockout period, the burner control box shuts down the system for safety.

Question 5

In a vaporising burner, how is the oil prepared for combustion?

Accepted Answer

By heating it on a hot surface until it turns to vapour

Answer

Vaporising burners work by allowing oil to flow onto a heated surface (the pot or sleeve) where it evaporates. The vapour then mixes with air and burns. They are simpler but less common than pressure jet types.

OFTEC Practice Test

OFTEC Practice Test

OFTEC Oil Burner Types and Operation