The seat is made from A105, F304,F11 and other common materials, applies M507Mo, Ni60, STL and other sealing surface materials,has a wide applicable scope.The base materials and welding wire is plane hardfacing welded with a nice welding combination. The welding cladding has high hardfacing, the thickness of processed pure alloy is less than 2mm, but the sealing face is durable with wide surface.