System resistance curves include which elements for a given speed and impeller size?

System resistance curves include which elements for a given speed and impeller size?

• A. Only head and efficiency
• B. NPSH, Head, Efficiency, and BHP
• C. Only the discharge coefficient
• D. Only the temperature rise

Answer: (B)

System resistance curves for a fixed speed and impeller size show how the system demands head at various flow rates and what the pump must deal with at those points. They include the head the system requires, the NPSH needed by the pump to avoid cavitation, the efficiency at each operating point, and the brake horsepower required to deliver that flow and head. The head tells you the pressure rise the system imposes, NPSH matters for suction reliability, efficiency shows how effectively the pump uses input power, and BHP indicates the energy burden on the drive. The other items listed (discharge coefficient, temperature rise) aren’t typically part of the system resistance characterization.

System resistance curves for a fixed speed and impeller size show how the system demands head at various flow rates and what the pump must deal with at those points. They include the head the system requires, the NPSH needed by the pump to avoid cavitation, the efficiency at each operating point, and the brake horsepower required to deliver that flow and head. The head tells you the pressure rise the system imposes, NPSH matters for suction reliability, efficiency shows how effectively the pump uses input power, and BHP indicates the energy burden on the drive. The other items listed (discharge coefficient, temperature rise) aren’t typically part of the system resistance characterization.