... -clamp butterfly valve is an advanced valve in the short distance between flange poles of 2 pipes with unique design,new ... , liquids, semifuid and solid powder in them, Which be long to the pipe system of peteoleum, chemical, textile, shipbuilding and metallurgic industries ... compressive sealing arount the entire seat.Friction free sealing for long cycle life (1)Seat is Cr13 matal alloy or hardfaced ...