... butterfly valve, with various rubber seats, EPDM,NBR,VITON,PTFE,e Rubber Seat For concentric butterfly valves. Various of rubber ... for different medium. There are soft seat and rubber seat with glass back.The feature is as following: ... Aging resistant -25°C~+110°CShort time +120°C NBR(X5)Fresh water,Salt, Strong base,Natural gas, Oil. ... resistant, corrosion resistant -10°C~+200°C Rubber seat