The water level in pressure tanks shall be within how many inches in non-pressure tanks within how many inches of the designated fire service level?

The water level in pressure tanks shall be within how many inches in non-pressure tanks within how many inches of the designated fire service level?

• A. 3 Inches; 12 Inches
• B. 3 Inches; 6 Inches
• C. 2 Inches; 12 Inches
• D. 4 Inches; 12 Inches

Answer: (A)

During a fire pump run test, keeping the water level at a precise height relative to the designated fire service level ensures the pump has the right suction head and can deliver the required flow without air pockets or head losses. The tolerance is tighter for tanks that are pressurized because small changes in water depth directly affect the head pressure; so the water level must be within 3 inches of the designated level. For non-pressurized tanks, the system is less sensitive to slight level shifts, allowing a larger allowable deviation of up to 12 inches while still ensuring sufficient water near the fire service level. This combination—3 inches for pressure tanks and 12 inches for non-pressure tanks—balances reliability with practical testing conditions.

During a fire pump run test, keeping the water level at a precise height relative to the designated fire service level ensures the pump has the right suction head and can deliver the required flow without air pockets or head losses. The tolerance is tighter for tanks that are pressurized because small changes in water depth directly affect the head pressure; so the water level must be within 3 inches of the designated level. For non-pressurized tanks, the system is less sensitive to slight level shifts, allowing a larger allowable deviation of up to 12 inches while still ensuring sufficient water near the fire service level. This combination—3 inches for pressure tanks and 12 inches for non-pressure tanks—balances reliability with practical testing conditions.