For drafting, the pump's rated capacity requires how many inches of water above the traditional strainer?

For drafting, the pump's rated capacity requires how many inches of water above the traditional strainer?

• A. 12 inches
• B. 24 inches
• C. 36 inches
• D. 48 inches

Answer: (B)

Drafting relies on keeping the suction submerged enough to prevent air from entering the pump and to maintain prime. The rated capacity assumes a certain suction head, so maintaining about 24 inches of water above the strainer ensures the pump stays submerged enough to avoid air ingestion and loss of prime, keeping the discharge at its intended flow. If the water is shallower, air can be drawn into the suction, prime can be lost, and the pump won’t deliver its rated capacity. Deeper water than 24 inches isn’t necessary for this purpose, so the standard minimum is 24 inches (two feet) above the strainer.

Drafting relies on keeping the suction submerged enough to prevent air from entering the pump and to maintain prime. The rated capacity assumes a certain suction head, so maintaining about 24 inches of water above the strainer ensures the pump stays submerged enough to avoid air ingestion and loss of prime, keeping the discharge at its intended flow. If the water is shallower, air can be drawn into the suction, prime can be lost, and the pump won’t deliver its rated capacity. Deeper water than 24 inches isn’t necessary for this purpose, so the standard minimum is 24 inches (two feet) above the strainer.