Manhole covers are used to cover up the deep wells and manholes on the road, it can protect the safety of pedestrians and vehicles. The shapes of manhole cover include round and square. Manhole covers are widely used in the drainage system.
The materials of manhole covers
The materials of manhole covers include ductile iron, grey iron, silicon plastic, cement and resin, of which grey iron and ductile iron are the most common materials,
but the cost of cast iron is higher, and it is easily stolen.
The advantages of ductile iron manhole covers
Manhole covers are usually made by ductile iron QT 500-7. The graphite in ductile iron has been useful to the anti-seismic, and it can effectively improve the mechanical property of cast iron.
Ductile iron manhole covers have higher strength and toughness. Their wearing resistance and corrosion resistance are better. Ductile iron is lighter than grey iron, and it is very strong, has less deformation, and non-easily cracked, so its life time is long. Moreover, the tensile strength of ductile iron is better than the grey iron.
The advantages of grey iron manhole covers
Grey iron manhole covers have good cast ability, wearing resistance and corrosion resistance, in addition, the cost of grey iron is lower than ductile iron.
The surface of manhole covers
The appearance of the manhole covers can be changed according to the customer's requirements. The surface of manhole cover should not have serious iron casting defects, such as cracks, sand holes and shrinkage. The surface should be smooth, clean, flat and painted rust resistant coating.
In China, most of iron foundries could produce manhole covers. As for the large manhole covers, most of iron foundries will produce them by resin sand casting process. Small manhole covers are usually made by green sand floor molding process or by automatic molding lines.
This article is from our Dandong Foundry's Cast Iron Manhole Cover Made in China.
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