Gu Chang Manhole covers ductile iron foundry in the test: 1. Appearance: No obvious casting defects. 2. Detection Manhole with a special tool diameter, the diameter of the sale of control of the size of manhole covers in the covers, ductile iron manhole covers offer the depth of 40mm bolt holes use special inspection by the seizure. Gu Chang-year foundry welcome you soon! Address: Taigu County, State Road 108 towns Hu Dong village crossing. Gu Chang today to introduce in ductile iron foundry castings Feeding Process design principles: (1) small pieces or thin castings should be considered part of the external feeding, solidification shrinkage process requires external pressure to provide support; (2) Heavy Heavy or large parts of the piece castings or simply do not need feeding limited feeding; (3) the casting is not limited to the external feeding feeding; (4) Cold Heavy iron solidification rate can be adjusted at the hot spot and casting temperature gradient, its role in feeding the casting is conditional. Ductile iron manhole covers Quote | Changchun ductile iron manhole covers | Chang in foundry provided by Gu Chang in foundry. Gu Chang-year foundry (www.sxcnzz.com) strong, credible, in Jinzhong machining industry has accumulated a large number of loyal customers. The company better work attitude and constantly improving innovative ideas will lead Chang and you work in the foundry into the brilliant, for a better future!