The raw materials used to make products such as manhole cover should be QT500-7 ductile iron, spheroidization rate is greater than 90, the nodularity is more than three, P < 0.08, the sulfur content of less than 0.05.
2, the well cover and the well seat surface should be smooth, casting, pattern marking and word mark clear without defect, no excess, no burr, no sharp edges, no warping deformation, no cracking, no cold shut, bulge, trachoma, shrinkage and other defects such as cracks or affect the use of inspection wells performance no, welding.
3, should cover the use of socket type structure, the lower part of the inner wall and the well to well frame is tightly matched with the three points should be used; the spring arm locking device to prevent accidental opening, stability and safety, prevent beating, displacement, reduce the vibration by impact significantly, greatly reducing the road surface covers the surrounding fragmentation may prevent noise. Should be used to prevent accidental closure of the safety hinge, required for stainless steel hinge shaft and diameter of not less than 14mm, so that the connection is more solid, the overall hidden in the flange type below the surface to enhance the security performance.
4、井盖与井座间的缝宽应符合如下要求：检查井盖净宽JKmm ≥600、缝宽a=a1+ a2 ㎜允许偏差范围8+2-4；检查井盖净宽JKmm <600、缝宽a=a1+ a2 mm 允许偏差范围6±2。
4, the well cover and the well seat width shall comply with the following requirements: manhole cover width JKmm = 600 a=a1+ A2 mm, width allowable deviation range of 8+2-4 is JKmm, <600; manhole cover width of a=a1+ A2 mm 6 + 2 allowable deviation.
5, the width of the bearing surface of the well should meet the following requirements:
The 5.1 is JKmm more than 600 manhole cover and base bearing width 6mm = 20; the manhole cover is JKmm<600, bearing surface width 6mm = 15;
The embedded depth of 5.2 wells, heavy inspection wells should be not less than 40mm, non skid tread: convex high 3mm;
This article from: Shandong ductile iron covers more information please click: to provide a satisfactory service for you http://www.kpp647.com we will ask questions, you are welcome to call!