Which of the following pumps is primarily used for oil solutions at low operating pressures?

The gear pump is specifically designed to handle oil solutions at low operating pressures, making it the ideal choice in applications where a consistent flow of viscous fluids is required. Gear pumps work by using interlocking gears to move fluid, relying on the gear design to create a vacuum that draws the liquid in and then pushes it out with a smooth and continuous flow. This mechanism is particularly effective for handling oils and other thick liquids, which allows them to maintain efficiency even under low pressure conditions.

While other types of pumps like piston pumps, roller pumps, and centrifugal pumps have their own uses and advantages, they are typically designed for different applications or fluid characteristics. Piston pumps, for example, are often utilized for high-pressure applications and can handle varying viscosities, but they aren't the first choice for low-pressure oil solutions. Roller pumps are commonly used for transferring fluids that do not harm the pump components and have certain shear sensitivity, while centrifugal pumps are more efficient for lower viscosity fluids and operate under different pressure dynamics. Therefore, the application of a gear pump stands out when specifically dealing with oil solutions and low pressure.