G2 Gas Fitter Practice Exam

When sizing an orifice for an atmospheric burner, knowing the gas pressure is essential because it directly affects the flow of gas through the orifice. The orifice size must be determined based on the characteristics of the gas being used, particularly its supply pressure, to ensure that the correct volumetric flow rate of gas is achieved for efficient combustion.

Gas pressure influences how much gas can flow through the orifice opening, which in turn affects the burner’s ability to deliver the necessary amount of gas for proper operation. Adequate sizing of the orifice in relation to the gas pressure helps prevent issues such as incomplete combustion or excessive emissions, ensuring the burner operates effectively and safely.

While factors like the size of the burner, the type of gas used, and the ambient temperature do play roles in overall burner performance, the primary factor for determining orifice size is the gas pressure. Knowing the pressure allows for accurate calculations to ensure the burner operates at optimal efficiency.