Ductile Iron Mechanical Collar Standards:ISO2531 EN545/598 Material :Ductile Iron GGG500-7 Specfication:DN50-DN2000 Ductile Iron Mechanical Collar Zhu Cheng Three-dimensional Pipeline Co. ,Ltd is the professional manufacture of ductile iron pipe fittings including flanged fittings ,tee ,socket fittings , joint , bend and so on from DN50-DN1800.Our products are exported to many areas every year , ...