The power supply manhole covers are divided into manholes and non-manholes according to the specifications. The non-manhole specifications are not specified. The composite manhole cover specifications are divided into the following four categories according to the net opening of the well seat: 600mm, 700mm, 800m, and 900mm.
In general, 600MM, 700MM, 800MM are more common, and they are also used a lot. But the most commonly used type is 600MM. But also one
These are around 550MM, and the utilization rate is also relatively high.
However, no matter what the size standard is, the selection requirements are selected according to the load bearing and the use environment, so not any one can choose arbitrarily when using the manhole cover.
In China, there are many national standards for manhole covers, including double-layer, single-layer, cast iron, ductile iron, composite, cement, magnesite, etc. The diameters of manhole covers are: 600mm, 700mm, 800mm, 750 * 450mm, 600 * 600mm, 400 * 600mm, bearing capacity, heavy 240KN, ordinary 100KN, light 20KN, extra heavy 8000KN and so on.
