Cavitation can occur in valves when used in throttling or modulating service. Cavitation is the
sudden vaporization and violent condensation of a liquid downstream of the valve due to localized low pressure zones. When flow passes through a throttled valve, a localized low pressure zone forms immediately downstream of the valve. If the localized pressure falls below the vapor pressure of the fluid, the liquid vaporizes (boils) and forms a vapor pocket. As the vapor bubbles flow downstream, the pressure recovers, and the bubbles violently implode causing a popping or rumbling sound similar to tumbling rocks in a pipe. The sound of cavitation in a pipeline is unmistakable. The condensation of the bubbles not only produces a ringing sound, but also creates localized stresses in the pipe walls and valve body that can cause severe pitting.
Read this white paper, courtesy of Val-Matic, to fully understand what happens when cavitation occurs in valves.
Table of Contents
- Introduction
- Cavitation Analysis
- Cavitation Data
- Valve Coefficient Data
- Example Application
- Conclusion & Recommendations
- References
