Check Valves
A check valve permits water to flow in one direction only. It acts as a backflow prevention device to prevent water in a residential system from backing up into a municipal water supply, and as backflow preventers on wells and boilers systems.
There are two types of check valves, swing types and spring types.
In the swing type, the pressure of the water forces the valve gate to ’swing’ open, but once the flow stops, gravity causes the gate to fall closed , preventing a reversal of the flow. This type of valve must be mounted vertically or horizontally to work properly.
In contrast, the gate in a spring check valve is spring loaded. Water pressure forces the gate open just as in the swing type, but when the flow stops, the spring, not gravity, forces the gate closed. This enables the valve to be mounted in any position and at any angle.
Various check valves sold for sump pump DWV lines
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Check valve used on a pressure line usually for a private well.
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