What is the purpose of a "spud" or burner orifice in a gas furnace?

The spud, or burner orifice, serves the critical function of measuring the amount of gas that is delivered to the burner in a gas furnace. Its design ensures that the gas flow is regulated appropriately, allowing for the combustion process to occur efficiently and safely. This measurement is essential because the proper amount of gas must mix with air to achieve optimal combustion. If too much or too little gas is delivered, it can lead to inefficient heating, increased emissions, or even dangerous situations like gas leaks or improper combustion, which could produce harmful carbon monoxide.

By accurately controlling the gas supply, the burner orifice plays a vital role in the furnace's overall operation and efficiency. Understanding this component is crucial for maintaining gas heating systems and ensuring they function safely and effectively.