The common operating gas pressure for natural gas is ______ inches of water column, and LP gas is ______ inches of water column.

• A. 1-3
• B. 11-20
• C. 0-1
• D. 3.5-11.0

Answer: (D)

Gas pressure is measured in inches of water column and tells you how much gas is available at the burner. Natural gas uses a much lower operating pressure than LP gas, so LP systems require higher regulator settings to push gas through lines and into the burner reliably. In practice, LP gas regulator settings sit around the high single-digit to low double-digit inches of water column, while natural gas stays well under 1 inch. The range that best matches the typical LP gas operating pressure is 3.5 to 11.0 inches of water column, which aligns with the higher pressure LP systems need. The other ranges either describe natural gas pressures or are not representative of the LP gas operating pressure. Always check the appliance’s data plate for the exact regulator setting.