For propane conversion, the orifice size is typically

• A. Be increased in size
• B. Be reduced in size
• C. Remain the same size
• D. Must be replaced with a larger regulator

Answer: (B)

Propane is more energy-dense than natural gas, so at the same regulator setting it would push more gas through the burner. To keep the burner at the intended heat input and maintain the proper air–fuel ratio, the orifice is reduced in size during propane conversion. This ensures stable flame, proper combustion, and prevents excessive fuel flow.