If your spray bodies are leaking water after the system (valve) is shut off, and the flow of water reduces over time, your heads are experiencing low head drainage. Low head drainage is where the lowest heads on the line weep the water in the pipe after that valve has shut down.
Check Valves are for use in sprinkler heads that have low head drainage or pooling around the sprinkler base as a problem. The drain check valve keeps lines from draining when the system is shut off. This saves water, reduces liability, and increases system life.
