Carbon Steel Lug Butterfly Valve Size: DN50-DN1200 Materials: Body: Cast iron, ductile iron, carbon steel, 304S. S, 316 S. S, and Aluminum bronze. Disc: Ductile iron, 304S. S, 316 S. S, and Aluminum bronze Shaft: 416 S. S and 304S. S and so on. Seat; EPDM, NBR, Viton, PTFE and so on. Strengths of lug butterfly valve: 1. Small size and light weight is easy to install and maintentance. 2. Safe and reliable operation, high interference-resistance.