Which of the following is NOT a characteristic of axial piston pumps?

Axial piston pumps are specifically designed to provide high efficiency and can operate at variable displacement levels, making them versatile for various applications, including those requiring significant pressure. The characteristic of "low pressure operation," however, does not align with typical axial piston pump performance.

These pumps are generally used in high-pressure applications, such as hydraulic systems, because they can produce a considerable amount of pressure while maintaining efficiency. This makes them suitable for industrial and mobile machinery where higher pressure operation is required for effective performance.

While the other characteristics, such as high efficiency, variable displacement, and compact design, are inherent to axial piston pumps, low pressure operation is not representative of their primary function or applications. As such, identifying it as the option that does not belong demonstrates an understanding of the fundamental characteristics and intended uses of axial piston pumps.