Where should a suction hose be positioned for drafting?

• A. The end of the suction hose should be as deep and free from debris as possible and placed in water source, with a good prime line to the pump.
• B. Near the surface of the water
• C. In air above the water
• D. Inside a closed container

Answer: (B)

Position the suction hose intake near the surface of the water. The goal in drafting is to keep the suction path wetted and to minimize the amount of air the pump has to pull out of the line. When the intake is near the surface, the pump faces a smaller static suction lift, which makes priming easier and helps maintain a steady flow. It also avoids pulling in bottom sediments and debris that can clog the line or strainers. Keeping the end submerged but not buried deep also helps ensure a reliable supply of water without introducing air into the system. Placing the intake in air or inside a closed container would prevent water from entering and collapse the prime, and positioning it too deep would require the pump to lift more water and bring in more sediment, increasing the risk of losing prime.