Nodular cast iron manhole cover manufacturer is a kind of nodular cast iron commodity. Nodular cast iron is made of spheroidal graphite through spheroidization and inoculation treatment, which effectively improves the mechanical function of cast iron, especially improves plasticity and resistance. Also high strength. Ductile iron is a kind of high-strength iron material developed in the 1950s. Its induction function is close to that of steel. It is based on its excellent function that it has been successfully used to cast some cluttered forces, strength, resistance and wear resistance. Highly demanding parts. Ductile iron has rapidly developed into the most widely used cast iron material after gray cast iron. The so-called "steel instead of steel" mainly refers to ductile iron.
Ductile iron manhole covers are usually divided into circular and square. In urban areas, the circular manhole cover is usually used. Because the round manhole cover is not easy to skew, it can better protect the safety of pedestrians and vehicles. The use of circular is mainly considered that the length of each diameter of the circular manhole cover through the center of the circle is the same, so if the manhole cover is rolled up by the vehicle passing through, the diameter will be slightly larger than the diameter of the wellhead below. Wide, the manhole cover will not fall into the wellhead.
However, if a square is selected, because the square diagonal is significantly better than each side length, when such a manhole cover is rolled up, it is easy to fall into the well along the diagonal direction of the wellhead, forming a hidden safety hazard. If the wellhead is round or significantly smaller than the manhole cover, the square manhole cover will not fall into the well. Here comes the question of the maximum use and savings of information. The use of the wellhead depends on the size of the wellhead. If it is necessary to install a square manhole cover that is much larger than the wellhead on the top, then the use and practical value of the data is naturally more useful than directly using the round manhole cover. Ensure the safety of the wellhead. In the countryside and cable wells, square is usually used, which can prevent the entry of liquids such as rainwater.