Which condition is necessary for a vacuum-type chlorination system to operate properly?

• A. Positive pressure
• B. Negative pressure
• C. No pressure difference
• D. High humidity

Answer: (B)

A vacuum-type chlorination system works by creating suction to pull chlorine into the water. This requires negative pressure inside the chlorination chamber relative to the surrounding atmosphere, which drives chlorine from the source into the water stream where it mixes for dosing. Without this pressure differential (positive pressure or no pressure difference), there’s no force to move the chlorine into the water. High humidity isn’t the factor that enables operation.