A pumper is rated at 100% at 1000 kPa, 70% at 1350 kPa, and 50% at 1700 kPa. At which pressure is the pumper rated at 70% of its rated capacity?

A pumper is rated at 100% at 1000 kPa, 70% at 1350 kPa, and 50% at 1700 kPa. At which pressure is the pumper rated at 70% of its rated capacity?

• A. 1000 kPa
• B. 1700 kPa
• C. 1350 kPa
• D. 1250 kPa

Answer: (C)

Understanding how discharge pressure affects the pump’s flow capacity. As pressure increases, the pump delivers less water, so the percentage of its rated capacity drops. The data show 100% capacity at 1000 kPa, 70% at 1350 kPa, and 50% at 1700 kPa. Therefore, the pressure that corresponds to 70% of the rated capacity is 1350 kPa. This is read directly from the pump performance data, and reflects the typical inverse relationship between head (pressure) and flow (capacity).

Understanding how discharge pressure affects the pump’s flow capacity. As pressure increases, the pump delivers less water, so the percentage of its rated capacity drops. The data show 100% capacity at 1000 kPa, 70% at 1350 kPa, and 50% at 1700 kPa. Therefore, the pressure that corresponds to 70% of the rated capacity is 1350 kPa. This is read directly from the pump performance data, and reflects the typical inverse relationship between head (pressure) and flow (capacity).