Inflatable Seated Butterfly Valves
Series 435, 436
ANSI Flange Compatible

Posi-flate's Series 435-436 butterfly valve with an inflatable seat is a dramatic breakthrough over conventional butterfly valves for dry solids and other processing. The Series 435 has a single-housing design with disc and shaft. The Series 436 features a split-housing design with intergral disc and shaft.

The seat design is the secret to longer life in two critical ways. It has only casual contact with the disc during valve opening and closing. It automatically compensates for wear when it inflates against the disc. Both features substantially prolong valve life.

In actual comparison tests, the Posi-flate butterfly valve out performed all other valves tested.

The unique design also provides a superior seal. By utilizing air pressure to expand the seat against the disc, it provides maximum sealing area and an even pressure distribution against the disc – every time.

For fail-safe monitoring, a pressure switch can be utilized to verify a positive seal.

The Series 435 and 436 valves come in standard sizes from 3” to 30”. Meets AWWA torque requirements.

Performance Features

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 build-up Double shaft seals Triple bearings Fail-safe monitoring

Temperature limits: may vary with materials of construction, -40 to 300 F. Air Supply: 115 PSIG maximum to seat, depending on seat material. Working pressure: 100 PSIG maximum, depending on seat material. Operating torque: may vary with application.

Available Materials of Construction

Housing: Cast Iron, nickel-plated cast iron Resilient Seat: Polyurethane, Buna-N, Silicone, EPDM, Fluorelastomer, FDA Materials Disc: Cast Iron, cast 316 stainless steel (satin finish or polished finish). Coatings available include nylon, teflon and nickel. Disc Screws: Carbon steel, stainless steel Bearings: Nylon, bronze

Seal insert: Nylon Shaft: Zinc-plated carbon steel, 316 stainless steel Shaft seal: Buna-N, Viton® Housing Gasket: Buna-N (Series 436) Retaining Ring: Carbon steel, stainless steel Housing Bolts: Carbon steel

Inflatable Seated Butterfly Valves Series 435, 436 Bulletin

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