Ductile manhole cover D400 

A ductile manhole cover with a D400 rating refers to a specific type of manhole cover that is designed to withstand heavy-duty traffic loads. The D400 rating is a classification system used to indicate the load-bearing capacity of manhole covers and grates. The "D" in D400 stands on EN 124 standard D class, which is a type of iron that has been treated with magnesium to increase its strength and durability. Ductile iron is known for its high tensile strength, impact resistance, and ability to withstand heavy loads. The number "400" in the D400 rating refers to the maximum load capacity of the manhole cover in kilonewtons (kN). In this case, a D400 manhole cover can support a maximum load of 400 kN, which is equivalent to approximately 40 metric tons. These ductile manhole covers with a D400 rating are commonly used in areas with heavy traffic, such as highways, airports, and industrial sites. They are designed to ensure the safety and stability of the infrastructure by providing a…