... or lug butterfly valve, with various rubber seats, EPDM,NBR,VITON,PTFE,e Rubber Seat For concentric butterfly valves. Various ... MaterialsApplicable mediumFeatureApplicable temperature°C Natural rubber(X1)Fresh water, Sea water,Salt, Strong base,Weak base,Food High elasticity-20°C~+85 ... C Hypalon(X2)Fresh water,Sea water,Salt, Strong base,Weak base,Weak acid,Alcohol. Oxidation resistant-20°C~+85° ...