A study of concrete volute pumps in the Netherlands, Finland and Canada showed 1315 years of total operation with one outage.
In the Dallas project, the Pavaho station was upgraded from 76,000 to 375,000 gpm in the same footprint using three concrete-volute pumps. Simulation allowed designers to get near zero cavitation despite tight approach flow and "candy cane" outlet geometries. Further, variable-speed drives give control as well as solving the problem of starting the large pumps on a relatively weak power grid.
The pumps were tested and accepted in 2012, three days before a storm that would have flooded the area. "This time, residents stayed dry," te Poele said.
Michael Kellogg, systems analyst, City of College Station, Texas, home of Texas A&M University, presented on innovative ways to contract control systems. The city-owned water and wastewater treatment facilities are serving a population growing steadily past 100,000 at 200 people per month, which has lead to a solid stream of expansion projects.
"Our challenge was to break through TITWWADI syndrome," Kellogg said, "Doing things the same way because ‘this is the way we've always done it'--buying the same kinds of systems from the same, familiar vendors."
But the bid process is labor-intensive and time-consuming: one must write RFPs, do reviews, advertise and get bids, and sit through vendor presentations. "Then you must take the lowest bid," Kellogg said, "or justify a best-value rationale for not doing so," another investment of time and effort.
So Kellogg examined alternative processes, including purchasing under a state contract at pre-negotiated discounts on approved products from approved vendors. "We buy our computers that way, why not our controllers?"
Rockwell Automation was already approved for federal contracts under GSA 70, and municipalities are eligible. These offer discounts off list prices and discounted field engineering costs. Panels can be built and shipped to a third party, and delivery costs are included. College Station purchased completed marshalling cabinets for a well field and shipped them to Houston, where a vendor put them in a modular building.
Snags included getting the city's purchasing people on board. "They were unaware and struggled with the wording of the cooperative agreement," said Kellogg. "We had to get Rockwell Automation involved to help them understand."
The purchase orders must come from the government, not a system integrator, Kellogg added, and not all products are on the contract. Since products must be shipped directly from the supplier, "your local distributor may feel left out," Kellogg said. "Copy them on the order so they can get credit."
Unfortunately, GSA 70 expired in September, 2013, and a replacement contract is one or two years away, but its lessons stand. "Take the time to research contracts," said Kellogg. "You may have a state contract, or your distributor or institution may have one." Contracts can save time and money on obtaining equipment, software and services, and the standardization can streamline operations.