Mitigating suction problems to increase pump capacity
Central Arkansas Water's (CAW) High-Service Pump Station No. 1A (PS1A) is its largest drinking water pumping station. The 72-MGD PS1A needed improvements to extend its life, improve pumping efficiency, operability, and reliability and mitigate suction piping constraints that had been causing cavitation.
Pre-design, Garver completed a “stress test” of the existing pumps to capture a range of flow conditions and created computational fluid dynamics model of the suction piping header and suction branches. This confirmed the station’s hydraulics and provided details related to the high velocities in pump suction piping. With construction completed, CAW confirmed Garver’s design mitigated the suction issues and increased pumping capacity.
Additionally, electrical switchgear was updated to address outdated pump speed controllers that used antiquated mag-drive and eddy-current drive technologies. A new motor control center lineup with variable frequency drives and reduced voltage soft starters was also installed, decreasing energy consumption, and improving operational flexibility.
Because the $470 million CIP has a significant impact on customer cities and the facility, it was critical for the process to include the input of all possible stakeholders, and a constant line of communication was crucial throughout the entire process.Jeff Sober Garver Texas Water Team Leader