Slam Dance! New Technology Eliminates Valve Slam
System operators have their work cut out for them when pumping applications deal with high head, surge tanks, or multiple pumps.
System operators have their work cut out for them when pumping applications deal with high head, surge tanks, or multiple pumps. A North Texas Wastewater treatment plant was learning this first hand. The North Texas utility serves four cities, the largest having between 70,000 and 80,000 people. Its lift station contains four 8 in. vertical centrifugal sewage pumps that feed a 600 ft. long, 48 in. diameter force main. Online since 1987, the station was equipped with traditional weight and lever air cushioned swing check valves.
“The check valves were breaking down. We repaired them, but they kept breaking internally. We were getting a lot of water hammer. This station takes a lot of flow, so it was hampering us. The station was down until we could get parts in or have them machined,” said a system operator for the plant.
The existing valves, from multiple manufacturers, were unreliable and it was difficult to find something to fit the unique circumstances of a vertical application. The existing air-cushioned swing check valves had to be rigged with additional external springs and cables in an attempt to combat slamming. The valves were closing hard, and a 1-year-old replacement valve had just broken a shaft pin. The installation was too dynamic for an ordinary check valve. The tall vertical run of pipe after the pumps created extremely fast flow reversals and water hammer after power failure. The existing valves had weighted levers with cables and springs anchored to the floor which made for a dangerous situation.
“This is one of the biggest suppliers of water in North Texas and the largest processor of wastewater,” noted John Bolender, President of Valve and Equipment, Huffman TX, a manufacturer’s representative. “They came to me looking for replacement valves that could replace slamming cushion swing check valves.”
Enter the Val-Matic SURGEBUSTER! Check Valve. Specifically engineered to handle high head applications, multiple pump systems, and systems known to surge, the SURGEBUSTER was designed to handle extreme applications.
The SURGEBUSTER achieves a rapid closure through a short disc stroke of 35° and still maintains a 100% flow area. What makes the SURGEBUSTER unique is the patented Disc Accelerator, the next generation in valve technology. The Disc Accelerator is a precision formed stainless steel mechanism that closes the disc rapidly, avoiding any slamming by flow reversal while also allowing the disc to be stabilized under flow conditions. The accelerator is fully enclosed and out of the flow path. The valve fully meets ANSI/AWWA C508.
“When they told me about their application, I suggested the Val-Matic SURGEBUSTER. I knew they hadn’t seen anything like it,” said Mr. Bolender.
The SURGEBUSTER was installed in place of the traditional swing check valve after a vertical elbow on the vertical discharge of an 8” pump. The results were so quiet, the flow could only be heard by placing your ear against the valve. The only way to tell that there was flow through the valve was by the top mounted valve indicator.
The traditional weight and lever swing check valves are now being phased out of the facility, and the Val-Matic SURGEBUSTER check valve has proved to provide some unexpected benefits. All SURGEBUSTER valves come with a fusion bonded epoxy coating on both the interior and exterior of the valve which is highly resistant to the corrosion sometimes associated with wastewater applications. And, due to the fact that there is no external weight and lever on the valve, the external moving hazard was eliminated making for a safer working environment.
“We were amazed at how quiet it was! After that we were pretty much sold. Another valve went down and I replaced it [with a SURGEBUSTER]. As the other two go down I will replace those as well,” the system operator said. WW
For more information on the SURGEBUSTER and to view tests conducted with the valve, contact email@example.com. Copies of the test are currently available on CD-Rom, DVD, and VHS.