New Valves, Pump Control Help Limit Pressure Surges

In 2005, the City of Moline completed a $21 million expansion and upgrade of its surface water treatment facility on the banks of the Mississippi River. Included in this upgrade were a new clarifier treatment building, laboratory building, SCADA control room, electrical systems, and valve upgrades.

The most significant upgrade with respect to the valves were the new Rubber Seat Ball Valves used on the pump discharge and Check-Mate Pump-Check protection system. Both were supplied by the Henry Pratt Co.

Prior to the project, the water plant was experiencing numerous problems with aging cone valves and their water distribution system. When required to operate, the existing cone valves would lift off their seats and send a surge of water and pressure into the distribution system causing main breaks on a regular basis.

The Pratt Rubber Seated Ball Valves, available in sizes 4” thru 60”, can be fitted with any operator a customer chooses including manual, electric, as well as hydraulic cylinders which can run off of air, water, or oil pressure supplied to the cylinder. The compact full port design allows these valves to be installed directly on the discharge end of pumps if required.

Moline’s new valves use existing plant water pressure supplied to the custom-made control cabinets, which then send the water through pipes in the floor to the valves below. When bringing a new pump on line, the discharge valves are only opened after enough pressure is built up to overcome the downstream head which is coming back toward the valve and pump. The double-seated drop tight design of these valves keeps unwanted surges from entering the system during start-up.

The Check-Mate pump control systems are built with opening and closing speed controls which allow the operators to extend the stroke time of the valve and fully control the amount of flow and pressure entering the distribution system.

Since being installed, the new ball valves and control system have minimized the surges and spikes in pressure and flow into Moline’s distribution system and have helped reduce the number of main breaks.

For information on the Moline Water Treatment Plant, contact Greg Swanson, General Manager via e-mail at [email protected]. For additional information on the Henry Pratt Double Rubber Seated Ball Valves and Check-Mate Pump check systems, contact Henry Pratt at 630-844-4000.