quick coupling Specialized in concrete pump parts and spare parts,like delivery pipe,elbow,coupling,fitting schwing,PM, quick couplingThis is the brief introduction of ... seamless or welded tube)material:45Mn2,high quality alloy steel pipe,st52,20#steel,etcsize:DN 125mm or DN 150mmWall thickness:4 ... can supply the 12m, 15m, 18m, 20m, 21m, 24m, 28m hydraulic concrete spreader and manual spreader.