Cavitrol III One-, Two-, and Three-Stage Trims
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Cavitrol® III trims are used for cavitating liquid applications in various globe and angle valve bodies(Contact your Fisher® sales office for angle valve information.)
One-stage trims are normally used where the pressure drop is below 99 bar (1440 psi);
two- and three-stage trims are normally used where the pressure drop is between 99 and 207 bar (1440 and 3000 psi).
The Cavitrol III trims are frequently used in pump recirculation and startup systems in the power, process, oil production, chemical refining,and other industries.
- Controls or Eliminates Cavitation Damage—Cavitrol III trim can lengthen valve service life and reduce maintenance downtime. The shape and spacing of holes in the cage wall circumference helps prevent cavitation in a properly sized valve, effectively controlling or helping to eliminate(depending upon service conditions) cavitation damage and resulting valve failure.
- Rangeability—Many special characterizations are available in Cavitrol III cages to match rangeability requirements of specific systems.
- Resistance to Erosion Damage—Standard hardened trim materials provide excellent wear resistance, resulting in longer trim life.
The contoured valve plug seat reduces fluid separation, helps direct fluid away from trim, and helps protect against erosion damage. - Versatility—Available in 1 to 24-inch globe or angle valves with weld-end or flanged-end connections.
- Easy Maintenance—Cage-type trim allows removal and inspection of parts without taking the valve body out of the pipeline. Fine particles very seldom cause the accumulation problem associated with labyrinth-type trim.
- Efficient Operation—A low inlet pressure to the final stage is maintained by the flow-down configuration and the successively larger flow area of each stage. At the third stage inlet,about 85% of the total pressure drop has already occurred and the vena contracta pressure remains above the liquid vapor pressure.
This helps to prevent cavitation in a properly-sized valve. - Trim Interchangeability—Cavitrol III one-stage trim is interchangeable with standard trims. Quick trim changes can be made with no additional parts, such as spacers, longer bolts, and special gaskets for valve sizes greater than 1 inch.