Which type of valve prevents backflow in plumbing systems?

The check valve is specifically designed to prevent backflow in plumbing systems, making it essential in various applications, including preventing contaminants from entering clean water supplies. This type of valve allows fluid to flow through it in one direction only, efficiently blocking any reverse flow.

When the fluid moves in the designated direction, the pressure pushes the valve disc or ball off its seat, allowing flow. However, if there is any attempt for the fluid to flow back in the opposite direction, the pressure difference causes the valve to close tightly, thereby preventing any potential reverse flow. This design is crucial in maintaining the integrity of plumbing systems, safeguarding against potential contamination and ensuring proper system functionality.

In contrast, while gate valves, globe valves, and ball valves serve important roles in regulating or controlling flow, they do not inherently function to prevent backflow. Gate valves are primarily used for on/off control, globe valves are used for throttling flow, and ball valves provide quick shut-off, but none are designed specifically to stop reverse flow in the way that check valves do.