Proper selection and placement of control, flow and relief valves is critical in a subsurface drip irrigation system design. Water flow rate and pressure throughout the SDI system should be precisely controlled to ensure efficient and timely water application. Valves play key roles in controlling pressure, flow and distribution under different conditions to optimize performance, facilitate management, and reduce maintenance requirements.

D&H systems include check valves, shut off valves, pressure relief valves, electronic remote control valves, pressure regulators, and air/vacuum pressure regulators. Valve sizes, maximum working pressure and valve materials are selected to properly meet each systems’ demands. Gate valves are installed at the discharge side of pump. Ball valves are used at the end of flushing lines to flush the system.

Quick-reacting pressure relief valves and surge-anticipating quick relief valves are used to protect the main and sub-main lines as well as pumps from excessive pressure. The quick reacting pressure relief valve is a safety valve that opens instantly, but closes slowly to protect the system against excessive pressure. The surge-anticipating quick relief valve protects the mainline, submains, and dripline manifolds against pressure surges.