Posi-flate manufactures the Series 585/586 inflatable seated butterfly valves which are designed for the most the most severe of applications. The heavy duty seat has been designed for higher operating pressures and temperatures. Standard valve sizes range from 2" (50 mm) to 24" (600 mm) and fit both ANSI and metric flanges. The Posi-flate valve is ideally suited for very abrasive materials such as sand, feldspar, fly ash and most other dry, granular materials, which reduce valve life. The inflatable seat design provides a better seal by utilizing air pressure to expand the seat against the disc, providing more sealing area and an even pressure distribution against the disc every time. The seat automatically compensates for wear when it inflates against the disc, extending valve life considerably. The valves are available in a wide variety of construction materials including stainless steel and aluminum.