What is the purpose of a check valve?

A check valve serves a critical function in water systems by allowing fluid to flow in only one direction. This one-directional flow mechanism is essential in preventing backflow, which can occur when the pressure in the system changes, for instance, when a pump is turned off. By automatically closing when the flow reverses, the check valve effectively acts as an automatic shutoff valve, safeguarding the pump and the plumbing system from potential damage that could be caused by backflow.

In contrast, the remaining options describe functions that check valves do not typically perform. Regulating water pressure is a task more suited to pressure-reducing valves. Controlling flow rate is typically achieved with flow control valves, which adjust the amount of fluid that passes through. Lastly, while sediment accumulation can be an issue in water systems, preventing sediment accumulation is generally managed through filtration systems or other means, not specifically through check valves. This understanding of the check valve's purpose is vital for maintaining the integrity and efficiency of a water distribution system.