Have a spherical closure unit with a port through the center, which allows control over flow. When the valve is turned so the bore aligns with pipe (open), water is able to flow through it. When rotated 90 degrees, the bore is perpendicular to the pipe (closed), and water cannot pass through.
Comes in 1.5", 2", and 3" sizes. Fits Schedule 40 PVC.
**Note: Ball valves can be used to control flow out of pumps, but this will not affect energy usage.