Processing Magazine

A peristaltic pump for chemical metering nixes valve maintenance

December 1, 2012

Watson-Marlow_Qdos“Water treatment and other process operations often involve chemical metering. Historically it’s been done using a diaphragm pump,” Rick Balek, sales manager, Industrial & Environmental Div., Watson-Marlow Pumps Group, says. Watson-Marlow is known as a peristaltic pump provider. With a peristaltic pump only the composition of the tubing that the pumped media travels through need be considered for chemical compatibility. Also of importance, however, Balek says, is that “Diaphragm pumps entail adding and maintaining valves.”

Watson-Marlow says its Qdos 30 pump range, introduced this June, is the first peristaltic pump specified for chemical-metering applications. The pump is said to deliver accurate, linear and repeatable flow performance from 0.0002 to 8.0 gallons per hour (GPH) at 100 PSI. There are no seals or valves in the flow path to clog, leak or corrode.

Besides reduced valve cost and less maintenance, another reason its peristaltic pumps are a cost-effective chemical metering solution is its “ReNu” pump-head technology, Watson-Marlow says. Quick and easy pump-head removal and replacement minimizes process downtime and requires no specialist tools, training or technicians. “It means you can rebuild a pump in about 30 seconds,” Balek says. “If the pump head fails, it is double-sealed from atmosphere, so the danger of spills or operator contact with hazardous substances is eliminated.”

Finally, the pump is fitted with a robotic-grade servo motor, for significant accuracy enhancement. “Overfeeding can arise from pump inefficiency,” Balek says. “But Qdos is so precise — two to four times more precise than other pumps — that savings are derived simply by the fact chemicals are not being wasted.”