The most important one is the bearing standard, that is to say, the bearing capacity of drainage ditch is divided into six grades. For example, A15 is the load of 15kn, equivalent to 1.5T. The load of ordinary car is C250, i.e. 250kN, equivalent to 25 tons. The fire truck is usually D400, which is equivalent to 40 tons. In fact, the cover plate on the drainage ditch is connected with the ditch body, so as to avoid looseness and noise. In fact, when we walk through most of the drainage ditches, there will be noise, mainly because the grate and the ditch body are not connected. This is a problem that is often ignored. I have found several pictures to illustrate the common types of grate, including the load-bearing grade. When designing a drainage ditch, the bearing grade is very important. If it is not done well, it will cause damage in use. The first one is the stamping cover plate - the bearing capacity is a15-b125 grade; stainless steel or galvanized steel is punched by die; special bolts are used to connect and fix with the drainage ditch body.
