Taigu Chang share basic knowledge of foundry ductile iron manhole cover with you: manhole covers are generally divided into round and square, in the city's road governance bunk ductile covers pictures, generally circular, because a circular covers not easy tilt, can better protect the safety of pedestrians and vehicles. If using a square double ductile covers manufacturers, since the square of the diagonal length of each side is significantly longer than its double-ductile covers, when such covers are rolled from double ductile covers size, it is easy diagonal direction of the wellhead It fell into the well, creating a safety hazard. If the wellhead made of round or significantly smaller than covers, square covers will not fall into the well. Taigu Chang in foundry double ductile covers features: flush with the road surface, the convergence of underground facilities inspection covers, the structure of the upper and lower layers a cast iron covers. This standard specifies the technical requirements for underground facilities Manhole double manhole covers, test methods, inspection rules. This standard applies to urban roads, highways and other motor vehicle or motorcycle may be with or manholes covers parked on the ground. Manhole covers main cover material shall comply with GB / T1348-1988 of. Sub cover should be non-metallic materials. Sub cover the manufacture of glass steel materials should be used. Ductile covers quote _ double bunk Luliang in ductile foundry covers _ Chang Chang on by Taigu foundry. Taigu Chang in foundry (www.sxcnzz.com) strong, credible, in Jinzhong machining industry has accumulated a large number of loyal customers. The company better work attitude and continuous improvement of innovative ideas will lead foundry Chang into the brilliant and you work for a better future!