What is the primary role of an orifice in a gas burner?

The primary role of an orifice in a gas burner is to control the flow of gas to the burner. Orifices are precisely sized openings that regulate the amount of fuel gas that can pass through them. This flow control is critical for ensuring that the burner operates efficiently and safely, achieving the desired flame characteristics for proper combustion.

By controlling the amount of gas that reaches the burner, the orifice helps maintain the correct air-to-fuel ratio, which is essential for optimal combustion performance. If the flow of gas is too high or too low, it can lead to incomplete combustion, producing excessive carbon monoxide or unburned fuel, thus posing safety hazards.

Other options relate to functions that are not associated with the role of an orifice in this context. Increasing the pressure of the gas is generally handled by regulators, igniting the gas involves spark ignition or pilot lights (not the orifice), and cooling the burner is unnecessary as burners are designed to operate at high temperatures during use. Therefore, controlling the flow remains the fundamental purpose of the orifice in a gas burner system.