APCO SRA Surge Relief Angle Valves were installed on a new Lift Station in the city of Phoenix. New freeway construction required the existing lift station to be relocated. The new location is in a hilly part of town with elevation changes, and the Lift Station discharges into a force main system. The 8” SRA-3000A Surge Relief Angle valves are designed to prevent line damage from surges that occur when the lift station pumps cycle on and off. The surge valves were installed and set to relieve system pressure at 135 psig. DeZURIK PEC Eccentric Plug Valves are used as isolation valves on the lines.
The surge relief valve is typically installed downstream of the check or pump control valves on the pump discharge header with the valve inlet connected to the side outlet of a tee and the valve outlet piped to the sump. The normally closed surge relief valve opens quickly when the system pressure rises above its adjustable relief pressure setting allowing fluid to be discharged from the system through the open surge relief valve to atmosphere. While the surge relief valve is open, the system is no longer contained, fluid compression is limited and surge pressure is controlled (green line). The valve will remain open as long as the system pressure exceeds the valve’s relief pressure setting. The valve will slowly begin to close at an adjustable rate as the surge pressure subsides and the system pressure falls below the valve’s relief pressure setting.