The type of shaft cover depends on the depth of the Airtight Manhole . Depending on the depth, the shaft can be divided into: shallow, normal and deep shafts.
A shallow hatch at a shallow depth of 75-90 cm (2′-3′). Shallow manholes are used in locations that are not subject to heavy traffic. They are also known as inspection chambers.
A normal Airtight manhole is one that can handle a certain amount of traffic and is usually square and rectangular in shape. It is run in a sewer line at a depth of 150 cm with a heavy cover on top.
A deep Airtight manhole is used in a location that is subject to heavy traffic. They are provided in depths greater than 150 cm with a heavy cover on top. They are large in size and along with deep manholes there is a descent facility.
Therefore there are corresponding norms and standards for manhole covers used in different environments – BS EN124.
Manhole cover material
According to the material, Airtight manhole covers can be divided into cast iron manhole covers, ductile iron manhole covers, cement manhole covers and composite manhole covers. Some people call composite manhole covers plastic Airtight manhole covers, but composite manhole covers have excellent performance that far surpasses plastic manhole covers. Composite manhole covers also include many types, including SMC manhole covers, BMC manhole covers, FRP manhole covers and so on.
Weight category for manhole covers
- A15 = Aid for pedestrians and cyclists
- B125 = Occasional traffic and driveway traffic
- C250 = Slow movement of cars and vans (For example in parking lots)
- D400 = Fast traffic on main road
- E600 = Heavy traffic like in warehouses, docks, etc. Motion with solid heavy tires
- E900 = For high traffic areas, e.g. at airports
According to the class, manhole covers are divided into three types, light manhole covers, medium manhole covers and heavy manhole covers.
More details and points
For better integration into the environment, a recessed Airtight manhole cover can be chosen for use in areas where paving, paving or infill is required. Only a few millimeters of the frame are still visible. If it is still less secure, you can add a lock as additional security.
It is necessary to provide safer protective measures and increase the tilting cover of the shaft. Opening is easier and safer.
When used in hotel projects, choose airtight hatches to prevent gas leakage.
Selection of manhole cover size
It is often believed that the size of a Airtight manhole cover should be measured by its external dimensions, but this is wrong. Hatches are manufactured and sold by the size of their clear opening (the size of the covered hatch) and not by the size of the hatch itself.
This is so that the cover can sit securely on top of the hatch. It doesn’t matter if the cover is square or round.
It is always advisable to use a hatch that precisely fixes the shaft or a larger dimension. A smaller size could fit.
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