Which statement correctly describes BHP and WHP in pump systems?

• A. BHP is the hydraulic power delivered by the pump
• B. WHP is the input shaft power to the motor
• C. BHP is the input shaft power, WHP is the hydraulic power output
• D. WHP is the rotational speed of the shaft

Answer: (C)

Understanding how power is measured in pump systems helps Make sense of BHP and WHP. Brake horsepower is the power actually supplied to the pump shaft from the motor—it's the input power to the pump. Water horsepower (hydraulic horsepower) is the power that the pump delivers to the water, the useful hydraulic output, calculated from the flow rate and the head. Because real pumps have losses, WHP is smaller than BHP, and the pump’s efficiency is WHP divided by BHP.

So the statement that matches this relationship is that BHP is the input shaft power, while WHP is the hydraulic power output. The other descriptions mix up where the power is measured or confuse speed with power. For example, hydraulic power is not the energy delivered to the shaft, and WHP is not simply the shaft’s rotational speed.