Nodular cast iron manhole cover installation when the collar from the original position will cause large friction, because in the process of lifting transport does not regulate the operation of socket will lead to the loss of a round, which will lead to the installation can be difficult, when installing the pipe or pipe uneven force, lifting is not it it will make the friction resistance increases, this will result in the tube is not easy to put in place.
Because the rope pulley are installed on both sides of the pulley when the pipe is not easy in the center line, even on both sides of the pipe can not guarantee the same hard tube uniform stress this is a rare event, for the loss of round pipe we need to use special tools to round the school. Because the lubricant used for soap and water, in the water groove or the high temperature condition, is almost not to mention lubrication, the product has good strength and toughness, more generous, better than the performance, strong corrosion resistance, so the installation is ductile iron more convenient, how to nodular cast iron the installation of anti-theft manhole cover is widely used in water supply pipeline in city.
Ductile iron manhole cover has good theftproof performance, anti-theft cast alloy cast iron, the non professionals can not be damaged, and the anti-theft mechanism covers special fundamentally solve the social problems of the manhole cover is lost. This product is not to say that all of the covers, the lathe solves the problem of noise generated by rolling the wheel, and he doesn't jump cover, manhole cover and the well ring is almost, reasonable size design is ensured, the oncoming traffic through without turning the shift cover.
It is also relatively long life of the general products in the minus 40 to 80 degrees under the normal use can be up to 30 years or more. In addition, its design is relatively reasonable installation is more convenient, easy maintenance form underground pipelines and facilities will be more beautiful and some of its relatively light weight, carrying capacity is relatively large, with good antiskid performance, pleasing color.