Manhole covers are an important part of urban infrastructure, mainly used to cover underground facilities such as drainage pipes, cable pipes, natural gas pipelines, etc. They not only protect underground facilities from external damage, but also ensure the safety of pedestrians and vehicles. According to different materials, shapes and functions, manhole covers can be divided into many types, suitable for different scenarios and needs.
Main types of manhole covers
1. Cast iron manhole covers
Cast iron manhole covers are the most common type, usually made of gray cast iron or ductile iron. Cast iron materials have high strength and durability, so cast iron manhole covers can withstand the rolling of heavy vehicles and are widely used in heavy-load environments such as urban roads and parking lots.
· Gray cast iron manhole cover: Gray cast iron has good casting performance and corrosion resistance, but relatively low strength, and is usually used in sidewalks and non-traffic areas.
· Ductile iron manhole cover: Ductile iron is specially treated during the production process, and its strength and toughness are greatly improved. It can withstand greater pressure and impact, so it is more suitable for roads or highways with heavy traffic.
2. Composite manhole covers
Composite manhole covers have gradually become popular in recent years. They are mainly made of a mixture of materials such as resin and fiberglass. This type of manhole cover is light in weight, easy to install and maintain, and has high corrosion resistance. It will not rust like cast iron manhole covers. In addition, composite manhole covers are non-magnetic and anti-theft, which is particularly suitable for areas with special needs.
3. Cement manhole covers
Cement manhole covers are usually used in municipal or rural areas with lower costs. Although they have higher strength and durability, compared with cast iron and composite manhole covers, cement manhole covers are heavier, more fragile, and difficult to move. Therefore, cement manhole covers are more used in places where heavy loads are not often encountered, such as sidewalks and gardens.
4. Plastic manhole covers
Plastic manhole covers are a type of lightweight manhole cover, usually used in places with light loads, such as green belts and residential areas. They are low in price and easy to install, but due to their limited load-bearing capacity, they are usually not suitable for heavy load areas.
5. Stainless steel manhole covers
Stainless steel manhole covers are usually used in areas that require beauty and cleanliness, such as shopping malls, scenic spots, airports, etc. Stainless steel has good corrosion resistance and a smooth surface, which is easy to clean and maintain. Due to its high cost, stainless steel manhole covers are more used for decorative purposes or special environments.
Manhole cover production and manufacturing
1. Cast iron manhole cover production process
The production process of cast iron manhole covers includes model design, smelting, casting, cooling and polishing. During the casting process, the composition and temperature of the molten iron must be strictly controlled to ensure the strength and toughness of the manhole cover. In addition, in order to prevent the manhole cover from loosening or making noise during use, many cast iron manhole covers are designed with anti-skid grooves or shock-proof rubber pads.
2. Composite manhole cover production process
The production process of composite manhole covers is different from the traditional casting process. It is mainly formed by molds, and materials such as resin and glass fiber are mixed and pressed and heated for curing. This process can not only reduce production costs, but also improve the corrosion resistance and durability of manhole covers.
3. Cement manhole cover production process
Cement manhole covers are usually formed by molds. First, raw materials such as cement, sand and gravel are mixed and poured into the mold, and then demolded after curing. This process is simple and low-cost, but the durability and corrosion resistance of the manhole cover are poor.
Application scenarios of manhole covers
1. Urban roads
Cast iron manhole covers, especially ductile iron manhole covers, are widely used on urban roads. Due to their high strength, they can withstand long-term crushing by heavy vehicles. In addition, modern cities have higher requirements for the aesthetics and safety of manhole covers, so many manhole covers are designed with exquisite patterns and anti-theft structures.
2. Parking lots and squares
In areas such as parking lots and squares, due to the large number of vehicles and people, cast iron or composite manhole covers with high strength and good durability are usually used. Such places have high requirements for the bearing capacity of manhole covers, and also require anti-slip designs to ensure the safety of pedestrians and vehicles.
3. Sidewalks and green belts
In light-load environments such as sidewalks and green belts, cement manhole covers and plastic manhole covers are more common. These areas do not require high bearing capacity for manhole covers, but have certain requirements for the convenience of installation and maintenance. Plastic manhole covers are suitable for these light-load places because of their lightness and low price.
4. Special places
In some special places, such as chemical plants, airports, ports, etc., the material and design of manhole covers need to be specially customized according to the actual environment. For example, chemical plants usually require manhole covers with extremely strong corrosion resistance, while airports and ports have extremely high requirements for the bearing capacity of manhole covers, so high-strength stainless steel manhole covers or customized composite manhole covers are usually used.
Manhole cover sales and market trends
With the acceleration of urbanization and the increase in demand for infrastructure construction, the market demand for manhole covers continues to expand. The sale of manhole covers is mainly concentrated in large-scale municipal projects, real estate development and private customization projects. In the future, with the research and development of new materials and the application of intelligent technologies, the types and functions of manhole covers will be more diversified. For example, some high-tech manhole covers have integrated sensors to monitor the operating status of underground facilities and help municipal departments to carry out timely maintenance and management.
In the sales process, manufacturers need to not only provide high-quality products, but also pay attention to the personalized needs of customers and provide customized services. The production and manufacturing of manhole covers are developing in the direction of automation and intelligence. In the future, more efficient and environmentally friendly manhole cover products will emerge to meet the diverse needs of the market.
