Anti-Cavitation Device Helps Quiet Noisy Valve
At Pepperdine University, even the horses kicked up a fuss about how noisy a nearby valve was when it opened and closed. The horse stable stood next to a reservoir tank in the pressure zone at an elevation of 545 feet.
At Pepperdine University, even the horses kicked up a fuss about how noisy a nearby valve was when it opened and closed. The horse stable stood next to a reservoir tank in the pressure zone at an elevation of 545 feet. The valve, which was at the tank's inlet, was serviced by a high pressure line from 812 feet elevation. When opened, the valve would vibrate so drastically from the pressure drop that the nearby horses would react wildly.
Singer Valve with Anti-Cavitation Trim
"The valve vibrated so much it scared us—and the horses," said Rick LaSance, electromechanic working supervisor in charge of water distribution of Los Angeles County. "We were afraid it was out of control."
By 1995, the valve needed to be replaced. LaSance knew, however, that specifying the same valve would neither eliminate the noise nor stop cavitation. Fortunately, he had heard of Singer Valve Inc. through a contractor who had specified the company's valves for another project. Knowing that L.A. County was unfamiliar with their valves, Grant LaBar, a Singer territory manager, offered LaSance a complimentary pump control valve as a test case.
"That's when we learned Singer makes an anti-cavitation trim," LaSance said. "So, we decided to try Singer's Altitude Valve with the anti-cavitation feature at the Pepperdine University tank."
"The valve was so quiet we couldn't believe it," LaSance said. "There is no more vibration and the horses calmed down too."
Four years after L.A. County installed the valve and anti-cavitation device, LaSance pulled it apart for inspection. "Everything looked like it was running perfectly," he said.
Since then, LaSance has often specified the setup.
The Anti-Cavitation Trim device is designed to solve high pressure drop problems and control continuous variable flows. It also helps prevent cavitation damage and handles up to 300 psi in one valve. It can reduce noise significantly and minimize vibration.
The cavitation process is contained within the stainless steel cages of the Anti-Cavitation Trim so the valve chamber parts are protected. Kari Oksanen, Singer Valve's general manager, designed the Anti-Cavitation Trim in the 1980s by adapting and improving existing technology.
"The secret is the second cage," he said. "A single cage anti-cav valve has severe limitations."
Ideal applications for the anti-cavitation setup is where outlet pressure approaches or is less than 30% of inlet pressure, such as reservoir fill valves, relief valve applications and low-pressure lateral discharge off of high-pressure mainlines.