Anti-Cavitation Control Valve Solutions

Cavitation occurs in a similar way to flashing with the formation of gas bubbles as the liquid pressure falls below vapour pressure. If the liquid pressure then recovers and rises above the vapour pressure the bubbles start to collapse or implode creating a shock wave which releases energy in the form of multiple micro jets.

The micro jets literally blast away pieces of the valves components or lead to severe pitting and accelerated corrosion. Cavitation is typically accompanied by accentuated hydrodynamic noise and vibrations in the valve and piping.

SchuF Control Valve Anti-Cavitation Solutions

• Pressure Drop Management
  The best means to eliminate cavitation is to control the pressure drop and ensure that it never falls below vapour pressure. This is achieved by using a multiple stage trim that reduces the pressure drop in stages. SchuF has a broad range of multistage trims that allow pressure to be let down in upto six stages in a step plug, or more in a stacked cage design.

• Valve Sizing and Design
  Proper valve sizing and body or trim design are also important factors in fighting cavitation.SchuF has specialised in the more complex dual and triple phase medium, typically slurries, and has developed its own advanced Cv sizing model for them. The model takes into account pressure drops at minimum, normal, and maximum flows as well as full details of inlet pressure and fluid conditions. The results are referenced against empirical data collected over the past 40 years in exact or similar applications and result in design recommendations for valve, seat and outlet size, body and trim material, as well as trim design for flashing or cavitating applications.

• Control Valve Diversity
  As a result of its focus on real life field control issues SchuF has designed a broad range of both in-line and angle valves. These valves are suitable for critical services as well as severe services that exhibit flashing and cavitation.