DISKFLO High Performance Butterfly


The DISKFLO Eccentric / Triple disc rotary control valve achieves bi-directional bubble-tight shutoff while maintaining low breakout torque at both high & low pressure drops. It is available in ANSI Classes 150 thru 1500 and in sizes 2 through 72-inch. This MASCOT rotary valve is available in carbon steel, 316 stainless steel and other alloys.

Eccentric Disc seating assures low breakout torque by utilizing the pressure drop across the valve to aid the seating process. Since much of the seating force is supplied by the pressure drop, the need for strong actuator seating force – and therefore breakout torque – is reduced. Combined with DISKFLO's high-thrust cylinder actuator and eccentric-cammed disc, it is possible to achieve especially high-performance throttling – even in large pressure drops close to the seat.

Eccentric / Triple Cammed Disc

A double offset and triple offset have been designed into the disc to lift it out of the seat immediately upon actuation. This avoids wear on the seat and disc, reducing leakage and parts replacement. It also improves throttling by eliminating friction.

DISKFLO Control Valve
DISKFLO Control Valve

DISKFLO Butterfly Control Valve Advantages and Features

  • General

    • Bubble-tight shutoff equal to ANSI Class VI
    • Low breakout torque assures accurate throttling, even close to the seat
    • Non clogging seat design
    • Easy removal
  • Metal Seat Eccentric-cammed disc

    • Shutoff better than ANSI Class IV
    • Disc pulls out of seat immediately, preventing seat wear
    • Accurate throttling due to disc profile when rotating into the seat
  • Single pivot-point, splined shaft

    • Lost motion minimized between shaft and actuator

    Bolted seat retainer

    • Uninterrupted gasket surface allows for a wide variety of gasketing

    Non-selective disc & shaft

    • Easier maintenance
    • Reduced cost –replace part needed, not entire assembly
  • Wafer body

    • Rugged and lightweight for easy handling and maintenance
    • One body serves ANSI Classes 150, 300 and 600 in sizes 2,3,4,6 & 8
    • Industry standard MSS SP-67 permits shorter flange bolting than ball or cammed valves, increasing safety and reducing possibility of leakage
  • Flow capacity

    Capacity greater than globe, plug and cammed control valves


    Concave disc

    Increased flow capacity

  • Disc stop in body

    • Prevents damage to seat due to overstroking
    • Permits in-line disc relocation during maintenance

    Wide variety of packing box configurations

    Purged bonnet and lubricator options

  • Fully enclosed, air purged transfer case

    • Extra safety
    • Prevents atmospheric corrosion of actuator internals
    • Disc position indicator mounted on transfer case

DISKFLO also capitalizes on established features of MASCOT product lines

  • Cylinder Actuator

    • High thrust for high-performance throttling
    • Compact and lightweight for easier servicing and maintenance
    • Fully interchangeable with ShearStream ball valve actuator
    • Actuator air pressures allowable up to 150 psi
  • Wide interchangeability

    • Spare par ts stocking requirements minimized
    • Inventory costs reduced
    • Many GFLO and VFLO parts are interchangeable with DISKFLO
  • Availability in variety of materials

    Carbon steel, 316 stainless steel and other alloys.

    Seat interchangeability

    Metal or Teflon® seats easily installed

  • Spool-type four-way positioner

    • Convertible between I/P and P/P
    • Calibration and maintenance easy due to fewer parts

DISKFLO Technical Specifications

The DISKFLO High Performance Butterfly Control Valve technical specifications are provided in the table below.

Body Type Wafer, light in weight, provides large flow and minimum pressure drop
Size Range 2-72 Inch
Pressure Class 1500 / CL2500 / CL4500 / API
Body Materials All castable Alloys 
End Connections Wafer, lugged, flanged
Gland Packing PTFE, Braided PTFE, Grafoil
Seat Ring Clamped-in, self aligned 
Shaft Splined - No lost motion or dead band 
Charactristics Equal Percentage, Linear and On – Off
Actuator Rotary spring cylinder, fully field reversible
Shut off class With metal seat - ANSI IV and replaceable Soft seat - ANSI VI
DISKFLO Cross-Sectional Drawing
Technical Diagram
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