What type of valve is used to prevent reversal of flow in a piping system?

A check valve is specifically designed to allow fluid to flow in one direction only and to prevent backflow in a piping system. This type of valve utilizes a disc or gate mechanism that opens when the flow is in the desired direction, allowing liquid to pass through. However, if there is any attempt of flow in the opposite direction, the disc closes, effectively blocking the reversal of flow.

This feature is crucial in various plumbing and drainage applications, particularly in systems where backflow could lead to contamination or damage. For example, in water supply systems and drainage applications, check valves maintain the integrity of the system by ensuring that used water does not re-enter the clean water supply.

The other types of valves listed do not serve this specific purpose of preventing backflow. A shutoff valve is primarily used to stop the flow of fluid entirely, while a ball valve and gate valve are generally used for controlling flow rather than preventing reversal of flow. Thus, the check valve’s unique function makes it the correct choice for preventing the reversal of flow in a piping system.