Wafer Butterfly Valves. Manufacturing standards: API, ANSI, DIN. Butterfly Valve Sealing: metal seated, resilient seated. Valve Size range: from 2 inch to 72 inch (DN50mm - DN1800mm). Pressure: from PN0.1MPa to PN6.4MPa. Applicable tempt.: from -40 degrees C to 425 degrees C. Valve Connection: Wafer. Valve Body materials: Carbon steel, Stainless steel.