Which statement best describes piston positive displacement pumps?

Piston positive displacement pumps are characterized by their ability to deliver a specific volume of fluid with each stroke of the piston. This mechanism allows them to generate high pressures, making them suitable for various applications where consistent flow volume and pressure are required. The statement that they have been largely replaced by centrifugal pumps refers to a trend in certain industries where centrifugal pumps are favored for their efficiency in handling larger volumes of low-viscosity fluids at lower pressures. This shift occurs because centrifugal pumps are generally easier to maintain and operate continuously without the need for the positive displacement action of a piston pump.

While piston pumps are still utilized for specific applications that require high pressure or unique operational characteristics, they are not as commonly used for high-volume or less viscous applications as centrifugal pumps are. Understanding the context of this transition helps highlight the specific strengths of piston pumps while acknowledging the broader industry tendencies towards centrifugal designs. Thus, the comparison to centrifugal pumps effectively illustrates the current landscape in pump technology and application.