The Type 57IL Isolator Lug butterfly valve inserts into the valve body during the injection molding process. The valve’s distinct design permits removal of downstream flange while maintaining full upstream line pressure. More than 300 stainless steel lugs are inserted into the valve during injection molding. Valves are available in 3 to 8 in. as lever style and 10 to 12 in. as gear-operator style.