... 4Durability carbon seel blind flange 1carbon steel,alloy steel ... flange, alloy steel flange, high pressure flange, slip on flange, slip on welding flange, welding ( welded )neck flange, blind flange, orifice flange, welding plate flange, welding neck collar ... , stub end ,etc.Application range: petroleum, oil, chemical industry, electric power, gas, construction and so on carbon steel blind flange ...