Masoneilan 21000 Series High-Performance Control Valves

Optimum control performance for a wide range of automated process control applications

Product Features

Model 87/88 Spring Diaphragm Actuator

  • Compact Multi-Spring Design Reduces Stem-Side Loading
  • Field-Reversible Construction
  • Rolling Diaphragm Helps to Reduce Friction and Wear
  • Constant Effective Area for Smooth Linear Control
  • Four Sizes Available Covering Large Thrust Range
  • Four Standard Spring Ranges for Wider Application Envelope
  • Side-Mounted Handwheel Option

Heavy Top Guiding

  • Larger Post Guide Area for Increased Stability
  • Positioned Outside of Direct Fluid Flow Path
  • Offers More Reliable Control Performance

Various Trim Options

  • Single- and Double-Stage Low Noise and Anti-Cavitation Trim
  • Standard Hardened Trim (Stellited or Equivalent Trim)
  • Quick-Change or Threaded Seat Rings
  • Reduced Capacities and Low-Flow Trims
  • Equal Percentage and Linear Characteristics
  • UOP Lockhopper Trim
  • Soft-Seat Design

Design Flexibility

  • Multiple End Connections
  • Various Materials
  • Angle Body Configuration
  • Bellows Seal Design
  • Piston Actuation Option
  • Extension Bonnets
  • Cryogenic Configuration
  • Low-Emissions Packing
  • DIN Version Available


  • Sizes: 3/4” through 8”
  • ANSI Ratings: Class 150 through 2500
  • ANSI Leakage: Class IV, V, VI
  • Cv Range: .11 to 640
  • Temperature Range: -150°F to 1050°
  • F Materials: Carbon Steel, stainless steel, chrome-moly, other alloys
  • Connections: NPT, flanged, socket weld, butt weld
  • Actuators: Spring-diaphragm, cylinder


  • Low pressure steam & water
  • General services
  • Flash tank
  • Fuel gas
  • Condensate recirculation
  • Superheater and reheat spray
  • Desuperheater water spray
  • Gland-steam pressure
  • Soot blower
  • Steam pressure
  • Auxiliary steam
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