Although the manhole cover is inconspicuous, its living environment is very poor. At the same time the responsibility of covers is high. Once the covers rupture will cause a great security risk.

Due to these high standards, man hole covers have historically been cast from metal, usually of ductile iron, and some of the manholes have been worn for wear, even using expensive bronze as the material. This covers the back is a good piece of metal, even if the sale of scrap iron can be worth hundreds of dollars. Therefore, although the rigging of the man-made manhole cover is severely punished, as long as there is an economic profit, it is inevitable that someone will take the risk.

However, with the development of science and technology, the FRP man hole cover appeared. This manhole cover process, labor costs saved; Second, its high strength, as long as a small amount of material can achieve the same effect with ordinary concrete, thus saving the material; Third, its corrosion resistance pole Strong, a manhole cover can be used for a long time, which in turn reduces costs; Fourth, the basic inside of this manhole there is no metal, even stolen is a rock, really once and for all solved the problem of stolen covers.

Goodsjack four column hydraulic press machine is suitable for making this type FRP man hole covers.