Unlike other valves that seal with friction, Posi-flate’s unique butterfly valve uses an inflatable seat to seal with air pressure. Thus it requires less torque and a smaller actuator, resulting in lower overall valve cost. Plus, the seat automatically compensates for wear, providing longer valve life.

Inflatable Seated Butterfly Valves

Heavy Duty Series

Less friction, low torque, less wear, longer life!

Posi-flate’s unique butterfly valve design uses air pressure to expand the seat against the disc, providing even pressure distribution for a bubble-tight seal, every time. Because the seat makes only casual contact with the disc during valve opening and closing, there is minimal disc impingement. This is in contrast to conventional butterfly valves where disc impingement leads to shaving of the seat, decreasing the overall performance and valve life.

Substantially less torque is required to open and close the Posi-flate butterfly valve, thus a smaller actuator can be used resulting in lower overall valve cost.

In actual comparison tests and documented field applications, the Posi-flate butterfly valve outperformed all other valves. In fact, a Posi-flate valve life of one to three million cycles, even in extremely abrasive applications, is not uncommon. For dry solids, gases and slurry applications, the Posi-flate inflatable seated butterfly valve is unsurpassed.

The Posi-flate Series 585/586 inflatable seated butterfly valves are designed for the most severe conditions. The seat is designed for heavy duty applications and higher operating pressures. Standard valve sizes range from 2″ (50mm) to 24″ (600mm) and fit both ANSI and metric flanges. A full line of actuators, limit switches and controls are available to suit individual applications.

Performance Features

  • Heavy duty
  • Inflatable seat compensates for disc and seat wear
  • Longer valve life
  • Minimal seat wear
  • No disc impingement
  • Ultra-low torque requirements
  • Lower actuator costs
  • More seal contact area
  • Proven excellent for abrasive and dry solids
  • Disc designed to prevent material buildup
  • Double shaft seals
  • Multiple bearings
  • Fail-safe monitoring

Temperature limits: -40° to 350° F (-40° to 175° C), varies with application and materials of construction.

Air supply: 135 psig (9.3 bar) maximum to seat, varies with materials of construction and application.

Working pressure: Full vacuum to 150 psig (10.3 bar) depending on application and materials of construction.

Operating torque: Varies with application.

Available Materials of Construction

  • Housing: Cast iron, stainless steel, aluminum, nickel-plated cast iron, epoxy coated cast iron, nylon coated cast iron
  • Resilient Seat: EPDM, Buna-N, polyurethane, fluoroelastomer, FDA silicone, FDA white Buna-N, FDA white EPDM, FDA white fluoroelastomer
  • 585 Disc: Cast iron, 316 stainless steel
  • 585 Disc/Shaft: 316 stainless steel (satin or polished), molded nylon over stainless steel shaft, superalloy, cast iron. PTFE and other custom coatings available
  • Bearings: Polymer, bronze
  • 585 Disc Screws: Carbon steel, stainless steel
  • 585 Shaft: Zinc-plated carbon steel, 316 stainless steel
  • Shaft Seal: Buna-N, silicone, fluoroelastomer, EPDM
  • Housing Gasket: Buna-N (Series 586), silicone, EPDM
  • Retaining Ring: Carbon steel, stainless steel
  • Housing Bolts: Carbon steel, stainless steel