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Florida Water Star Technical Manual

Irrigation system criteria

General design

Check valves


Water pressure in an irrigation system will affect the performance of sprinklers and emitters. The accumulated weight of water increases pressure as gravity pulls on water. Sprinkler height differential creates varying pressures. Thus pressures can build at lower heads.

Declining Pressure Diagram

Decline creates greater water pressure at lower head.

Check valve installed in a pop-up sprinkler head

Check valve installed in a pop-up sprinkler head.

This additional pressure can cause a standard irrigation head to remain partially open and “weep” or “bleed” after the solenoid valve closes, which causes any remaining water in the pipe to drain out and go to waste. Up to 1 gallon of water can leak from low-lying heads every time the system shuts off. Significant water loss can occur over time in systems with numerous low-lying heads.

A check valve is a component that increases the resistance of the sprinkler pop-up mechanism and prevents water from weeping out.

Requirements and certification

Sprinklers in low-lying areas have check valves.







Locations that typically require check valves are the site perimeters that are at a low point in a slope away from the building. Heads requiring check valves must be clearly identified on the irrigation system design and are to be field-verified by Florida Water Star Inspectors.

St. Johns River Water Management District
4049 Reid Street, Palatka, FL 32177