... and CharacteristicVentilated butterfly valve use same material as body to process gasket, the suitable temperature is according to material of body,nominal ... to Face: GB/T12221Pressure Test: GB/T13927MaterialCast Steel:ASTM A216 WCA,WCB,WCCStainless Steel: ASTM A351CF3,CF3M,CF8,CF8M,CF8CCr-Mo ... Steel: ASTM A217 WC1,WC6,WC9,C5,C12,C12A,Low Temperature Steel: ASTM A351 LCA,LCB, ...