Cavitation involves vapor bubbles forming where liquid pressure falls below vapor pressure, followed by their collapse as pressure recovers. It can generate noise, vibration and material damage even when the valve body is within its pressure rating.
Pressure recovery determines the risk
The lowest local pressure inside the valve is not necessarily the measured outlet pressure. Two valves with the same inlet and outlet pressures can have different internal pressure-recovery behavior. A general body pressure class therefore cannot tell you whether the duty is cavitation-resistant.
Separate diagnosis from assumptions
A gravel-like sound may suggest cavitation, but noise alone is not a complete diagnosis. Record flow, inlet and outlet absolute pressure, liquid temperature and vapor pressure. Review where damage appears and whether it changes with operating point. Entrained gas, pipe resonance or loose internals can produce other symptoms.
Address the mechanism
Potential approaches include redistributing the pressure drop, changing the system operating conditions or using purpose-designed severe-service trim. Harder materials may delay damage but do not remove the vapor-collapse mechanism. Ask the supplier to evaluate the selected valve’s recovery factors and acceptable operating envelope rather than promising a universal cavitation-free V-port.
Practical checklist
- Provide liquid vapor pressure at operating temperature.
- Use absolute pressures for the vaporization assessment.
- Review normal and low-flow high-ΔP cases.
- Consider a different valve family when severity demands it.
Discuss your application
Send the process conditions and required valve function for a configuration review. Request a technical quotation ↗