What is the primary function of positive-displacement pumps in water systems?

Positive-displacement pumps are designed to move a fixed volume of liquid with each cycle or stroke of the pump. This characteristic enables them to provide accurate measurements of the fluid being transported, making them ideal for metering purposes. In water systems, this means that they can effectively dispense and control the addition of treatment chemicals in precise amounts, which is vital for maintaining water quality and ensuring effective treatment processes.

For instance, when chemical dosing is required to disinfect water or to adjust the pH, a positive-displacement pump can deliver consistent, accurate doses irrespective of variations in pressure or flow conditions in the system. This reliability in metering distinguishes them from other types of pumps that may not maintain the same level of accuracy under varying operational conditions.

On the other hand, while high-volume water movement, filtration, and sewage pumping are essential functions in different contexts within water management, they do not align with the primary function of positive-displacement pumps, which emphasizes precise volume control over sheer flow rate.