At 1350 kPa, the pumper is rated at what percentage of its rated capacity?

At 1350 kPa, the pumper is rated at what percentage of its rated capacity?

• A. 70%
• B. 60%
• C. 100%
• D. 50%

Answer: (A)

Understanding how a pump’s performance curve works is key. The rated capacity is the maximum flow the pump can deliver under its standard testing conditions with minimal back pressure. As discharge pressure increases, the pump must work against more head, and the flow along the curve decreases. At 1350 kPa, which is a substantial back pressure, the curve shows the flow dropping to about 70% of the rated capacity. In other words, with the same engine speed, the pump delivers roughly seven-tenths of its nominal GPM at that pressure. This illustrates the general principle: higher pressure means lower flow, while lower pressure allows approaching the full rated capacity.

Understanding how a pump’s performance curve works is key. The rated capacity is the maximum flow the pump can deliver under its standard testing conditions with minimal back pressure. As discharge pressure increases, the pump must work against more head, and the flow along the curve decreases. At 1350 kPa, which is a substantial back pressure, the curve shows the flow dropping to about 70% of the rated capacity. In other words, with the same engine speed, the pump delivers roughly seven-tenths of its nominal GPM at that pressure. This illustrates the general principle: higher pressure means lower flow, while lower pressure allows approaching the full rated capacity.