Problem: A major freeway project required the city of Phoenix to relocate a wastewater lift station into a hilly area with significant elevation changes. The new station discharges to an existing force main, making it susceptible to transient pressures when pumps cycle on and off. Without targeted protection, rapid pressure spikes — water hammer — could have damaged the force main, valves and pump equipment, jeopardizing reliability and increasing maintenance costs.
Solution: To control transients at the source, engineers installed 8-inch APCO SRA-3000A Surge Relief Angle Valves. Each valve was set to open at 135 psig, giving the system a fast-acting “safety outlet” that discharges pressure only when the setpoint is exceeded, then reseats to maintain normal operating pressure. This configuration limits the magnitude and duration of surge events associated with pump starts and stops in the lift station’s force main environment. DeZURIK PEC Eccentric Plug Valves were selected as isolation valves, providing reliable shut-off and service access while complementing the surge relief strategy.
Result: Following commissioning, the SRA surge relief valves have performed as intended — relieving transient overpressure conditions during pump cycling and helping prevent line damage in the force main system. By mitigating water hammer in a topographically challenging setting, the station maintains stable operation, protects downstream assets and reduces the risk of unplanned outages tied to surge events. The combination of purpose-set surge relief (135 psig) and robust isolation via PEC Eccentric Plug Valves supports safer, more predictable operations for the relocated lift station, aligning with the city’s reliability goals amid changing infrastructure demands. 320-259-2000; www.dezurik.com
