Circular Road Manhole (Type 1A)
Castings of Surface Boxes; Manhole Covers; Frames; Inspection Covers and Frames shall be of Grey Cast Iron.
All Castings are sound, homogeneous and free from sand, blow holes, chill, cold shuts, scab and other deleterious defects.
Castings are free or Warp after they have been dressed and fettled seat evenly without rocking.
Castings are capable of withstanding, without signs of fracture or permanent set the appropriate force as specified:
Heavy Duty: 135 (kn)
For use in carriageways and capable or bearing wheel loads of up to 12 metric tons.
Castings are coated in a bituminous solution.
All manhole covers and frames & inspection covers and frames have the NIBF (Natal Iron and Brass Foundry) logo cast on the top of the cover.
The size, type and weight are cast at the bottom of the cover.
For large quantities a customer may request their name or logo’s on the casting.