Manhole covers are essential components of urban infrastructure, supporting systems such as water supply, drainage, electricity, communication, and other pipelines. The theft of these covers results in the loss of public property and damage to underground facilities, creating significant safety hazards for both pedestrians and vehicles. This can lead to various safety incidents.

I. Mechanical Lock Anti-theft Technology

Mechanical lock anti-theft is the most widely used traditional anti-theft technology. It realizes the locking and fixation of manhole covers and well bases through mechanical structures to prevent unauthorized opening.

1. Embedded Lock Body Structure: The lock body is integrated within the manhole cover or well base, ensuring that the lock cylinder is not exposed. This design effectively prevents damage from tools such as crowbars. The lock cylinder uses specially shaped keys that are issued exclusively to property management departments and operation and maintenance units. Each key is marked with a unique code, enabling a precise "one lock, one key" system, which significantly reduces the risk of unauthorized access.

2. Interlocking Buckle Structure: The edge of the manhole cover is designed with interlocking buckles that match the well base. After the manhole cover is closed, it is automatically locked by gravity or manual rotation. Special tools are required to release the buckle engagement to open the cover. This technology features high structural stability, and its pry resistance is improved by 60% compared with ordinary flat covers.

3. Pin Lock Fixing Technology: Stainless steel pin locks are installed at multiple positions around the manhole cover. After closing the cover, the pin locks are inserted into the reserved holes of the well base and locked, reinforced with anti-loosening nuts. It can resist strong impact and prying force, making it suitable for manhole covers under heavy-load working conditions, such as roads and industrial parks.

II. Material-based Anti-theft Technology

Material-based anti-theft technology fundamentally eliminates the motivation for theft. It abandons traditional cast iron manhole covers that are prone to theft and adopts materials with no or low recycling value for production.

1. Composite Material Manhole Covers. Made from glass fiber and resin as the primary raw materials through molding processes, these manhole covers possess both high strength and corrosion resistance. They do not have the recycling value of scrap iron, fundamentally eliminating theft motivated by profit from resale. The weight of this type of manhole cover is only 1/3 of that of cast-iron manhole covers of the same specification, facilitating easy installation, while also having good anti-slip and noise reduction performance.

2. Recycled Material Modified Manhole Covers. Modified manhole covers are made from recycled raw materials such as waste plastics and rubber, with reinforcing agents and stabilizers added. They not only realize resource recycling, but also completely avoid the risk of theft due to the absence of metal components. This type of manhole cover is low in cost and suitable for light-load scenarios such as green belts and sidewalks.

To sum up, the anti-theft technology for manhole covers in industrial parks has formed a diversified protection system of mechanical locking to build a solid physical defense line and material innovation to cut off theft motivation, providing a solid guarantee for the asset security of underground pipeline networks in industrial parks.