How to distinguish between heavy-duty manhole covers and light-duty manhole covers?

Heavy and light manhole covers can be distinguished by the following aspects:

1. Application scope and occasions: Heavy duty manhole covers are usually used in places with heavy loads, such as airports, highways, docks, etc., because these places need to withstand significant weight and pressure. Lightweight manhole covers are suitable for relatively light load environments such as sidewalks, small squares, residential areas, and bike lanes. ‌

2. Material: Heavy duty manhole covers are usually made of cast iron because cast iron material can achieve the required strength. Lightweight manhole covers can be made of other materials, such as composite materials, resin materials, polymer materials, etc.

3. Thickness and weight: Heavy duty manhole covers are usually much thicker and heavier than ordinary manhole covers. In contrast, lightweight manhole covers are thinner and lighter in weight.

4.Height of manhole cover: The depth of the heavy-duty manhole cover embedded in the well seat should not be less than 50mm, and the total height should not be less than 75mm; The depth of the lightweight manhole cover should not be less than 30mm, and the total height should not be less than 50mm. ‌

5.The thickness of the bottom reinforcement of the manhole cover: The thickness of the bottom reinforcement of heavy-duty cast iron manhole covers is not less than 100mm, while the thickness of the bottom reinforcement of lightweight cast iron manhole covers is generally around 50mm.

6.The annotation on the manhole cover panel: Cast iron manhole covers are classified into different grades according to their bearing capacity, such as A15, B125, C250 for light weight, D400, E600, F900 for heavy weight.