How to Distinguish between Heavy Covers And Light Covers?

The covers can be simply divided into heavy duty covers, light duty covers and ordinary type covers, Light manhole cover is to allow pressure 210kN or steam-10 level main vehicle, heavy manhole cover refers to the factory inspection to allow pressure 360kN or super steam -20 main vehicle.

Their applications are different, heavy duty manhole covers are used in motor vehicles to exercise, parked roads, roads and parking place, ordinary covers are used in slow lanes, residential quarters and access roads, light duty manhole covers are used in green belts and somewhere that motor vehicles can not drive and park.