Where should the drafting suction be placed relative to the water surface?

Where should the drafting suction be placed relative to the water surface?

• A. 18 inches from the top and 12 inches from the bottom
• B. 12 inches from the top and 18 inches from the bottom
• C. 6 inches from the top
• D. 3 feet from the top

Answer: (A)

Drafting suction must stay submerged enough to prevent air from entering the pump, but not so close to the bottom that sediment and debris are drawn in. Placing the intake about 18 inches below the surface keeps it under water even with surface movement and helps minimize air entrainment, while keeping it roughly 12 inches above the bottom avoids drawing in bottom dirt. This balance makes the suction position in option A the best choice.

Drafting suction must stay submerged enough to prevent air from entering the pump, but not so close to the bottom that sediment and debris are drawn in. Placing the intake about 18 inches below the surface keeps it under water even with surface movement and helps minimize air entrainment, while keeping it roughly 12 inches above the bottom avoids drawing in bottom dirt. This balance makes the suction position in option A the best choice.