Pump Connector Helps Achieve 25-Percent Increase in Suction Pressure

Oct. 1, 2010
The Metraflex Co.2323 W. HubbardChicago, IL 60612312-738-3800www.metraflex.comCircle 64 The Indiana University Cyclotron Facility (IUCF) in Bloomington,

The Metraflex Co.
2323 W. Hubbard
Chicago, IL 60612
Circle 64

The Indiana University Cyclotron Facility (IUCF) in Bloomington, Ind., is a state-of-the-art multidisciplinary facility. At peak operation, it requires 4.0 megawatts of power. With this power load, cooling of equipment is critical.

When the facility was built, two 200-hp, 3,700-gpm vertical split-case double-suction chilled-water pumps were installed in an area with inadequate overhead clearance, Bill Starks, IUCF mechanical designer, said.

“When we first started up the pumps,” Starks said, “we were going through bearings and wearing out the impellers in three months' time. The pump manufacturers confirmed it was a piping issue. It's very critical, especially on a split-case double-suction pump. It has to be equal flow to each side. Otherwise, if the flow is concentrated to one side, it will result in an uneven thrust load on the impeller. The uneven load would wear out the bearings and also cause the impeller to shift to the side. Eventually, the impeller will start hitting the housing.”

A CRV Flex pump connector from The Metraflex Co. increased suction pressure by about 25 percent, from 3.5 to 4.5 lb, and increased output pressure by 10 psi at the same flow rate.

“We've been running six months on our backup pump without bearing failure or any increase in noise,” Starks said. “Usually, the bearings would start to get noisier, or you start wearing the impeller, and you get some type of cavitation noise. Right now, it's still the same as Day 1.”

The IUCF is so pleased with the performance, it is planning to replace the diffuser on the main pump with the CRV Flex.