... corrosion,etc.So the ductile iron pipe fittings are widely applied to such compressive pipes as water pipeline,Oli pipeline ,sand pipeline ... ,sewerage pipeline,etc, All types of ductile iron pipe fittings 2. ... of ductile iron >grade three(GB9941-88)5.Pipe and fittings Interface:1.double flanged ,contains rubber gasket,Bolts&Nuts ...