Water Treatment Valve Selection: Corrosion, Cavitation
Water treatment looks simple on paper — it is only water — but the reality of chlorine, pH swings, slurries and aggressive chemistries makes valve selection a discipline of its own.
Corrosion resistance
Potable and process water are handled in stainless steel, ductile iron with approved linings, or engineered plastics such as PVC, CPVC and PVDF. The choice depends on chlorides, disinfectants and pH. Chlorine service is particularly aggressive to rubber and many metals.
Cavitation in control duty
Pressure-reducing and control valves that drop a lot of pressure across a single stage will cavitate. The fix is multi-stage, cage-guided trim or a specialized anti-cavitation design that keeps pressure drop distributed.
Sludge, lime and solids
Sludge lines and lime dosing carry abrasive solids. Eccentric plug valves, knife gate valves and pinch valves survive where a standard ball or butterfly seat would be torn apart.
Actuation and remote control
Modern water plants are automated, so valves carry electric or pneumatic actuators with positioners, limit switches and fieldbus connectivity for SCADA integration.
Read the water chemistry first, then pick the valve. The chemistry decides everything downstream.
