Stormwater and pipes are reignforced, they can be found in classes of 20D, 40D,60D and 80D. The different number identifications relate to the weight capacity that they can sustain, 20D implies sustenance of a weight not exceeding 20 kilo-Newton, 40D can sustain up to 40kilo-Newton and so on, in proportion with the class number. they differ in the amount of steel per pipe, with the 60D class increasing its thickness by 12mm compared to the 20D pipe.Our Culverts allow water to flow under a road, railroad, tail or similar obstruction from one side to the other side. Our stormwaters are a meter long and the diameter range from 300mm to 600mm.