A "spud" or burner orifice is used to control what aspect of a gas burner?

A "spud" or burner orifice plays a crucial role in regulating the flow of gas to the burner. It determines the size of the opening through which gas passes into the combustion area, thereby controlling the amount of gas that enters the burner. This is essential for achieving the correct combustion process and ensuring the burner operates efficiently. The precise control of gas flow affects the burner's heat output, efficiency, and emissions.

The orifice size is specifically designed to allow the appropriate amount of gas to mix with air for combustion. If the gas flow is too high or too low, it could lead to issues such as incomplete combustion, increased emissions, or poor burner performance. Thus, the primary function of a spud or burner orifice is firmly associated with managing the gas supply rather than influencing manifold pressure, air supply, or vent fan operation.