How Do Check Valves Work?
Other People Are Reading
-
Basics
-
Check valves come in the form of ball check valves, cone check valves, and disk check valves. Check valves are used to close off piping and to prevent backflow. Backflow occurs when the substance in the pipe flows in the opposite direction when the valve is closed. Check valves can be found in many places, including city water and sewer systems, where a backup could cause problems on a large scale.
Ball
-
Ball check valves are very common. A ball in the shell of the valve fits tightly against the side of the valve where the water comes in. A spring holds the ball in place and helps seal it tight. Water pushing through the pipe moves the ball against the spring, allowing water through the valve. When the water is turned off, the ball is pushed into place by the spring and keeps water from flowing backward through the pipe.
-
Cone
-
Cone valves are similar to ball check valves, but the plug that seals the valve is shaped like a cone. Another name for this type of valve is a lift check valve. The cone is held on a bar, allowing it to lift out of the way when the water is flowing and drop back into place when the water is off. If water backflows through the pipe, it pushes up against the cone, creating a seal that keeps it from going any further.
Disk
-
Disk valves are also known as swing check valves. They operate in the same manner as ball and cone valves, but the plug that settles over the opening is a disk. Disk and cone valves tend to wear down more because they have more moving parts and because they get bumped around on top of the flow of water when it is turned on.
-
