Luzhongbao 1200×740×60 Split-Type Cast Iron Square Manhole Cover

Luzhongbao 1200×740×60 Split-Type Cast Iron Square Manhole Cover: An Excellent Protective Solution for Heavy-Duty Areas.

The Luzhongbao 1200×740×60 split-type cast iron square manhole cover is a high-performance protective facility specifically designed for heavy-duty areas such as urban main roads, ports, terminals, and airports. The product is precision-cast using QT500-7 grade high-strength ductile iron, strictly adhering to the GB/T23858 national standard. Its innovative split-type structure divides the traditional monolithic cover into two independent units, significantly reducing the weight of a single piece and greatly facilitating daily opening and maintenance operations. The large-size rectangular design of 1200mm × 740mm perfectly accommodates large inspection shaft openings, while the 60mm thickened structure ensures exceptional structural stability even under heavy loads, providing a safe and reliable working channel for the maintenance of large pipelines such as power, communication, and water supply and drainage systems.  

Compared to similar products, Luzhongbao has established significant advantages in five key dimensions:

- In material science, QT500-7 grade ductile iron is used, with tensile strength ≥500 MPa and yield strength ≥320 MPa, offering mechanical properties far superior to ordinary cast iron materials.  

- In structural design, the innovative split-type structure combined with precision casting technology addresses the industry challenge of difficult opening for large-size covers.  

- In load-bearing performance, the internal three-dimensional reinforcement rib network, optimized through finite element analysis, ensures more scientific load distribution.  

- In anti-settlement technology, the wide-edge flange and anchoring system work together to effectively prevent surrounding settlement.  

- In service life, multiple anti-corrosion processes ensure the product maintains an ultra-long service life of over 30 years even in harsh environments.  

Detailed Explanation of Core Technical Advantages  

1. Innovative Split-Type Structure and Heavy-Duty Design  

The product features a precision-cast split-type structure connected by high-strength concealed hinges, allowing a single person to complete the opening operation. The internal three-dimensional reinforcement rib network adopts a composite design of radial and grid patterns, with key load-bearing areas reaching a thickness of 70mm, increasing load capacity by over 60%. Rigorous testing has certified the product to meet D400 grade (400 kN) load-bearing standards, with some models achieving E600 grade, fully meeting the ultra-heavy-duty requirements of special scenarios such as port machinery and airport cargo handling.  

2. Exceptional Anti-Settlement and Stability Performance  

The manhole frame adopts an integrated deepened design, combined with a 300mm wide flange, forming a stable "inverted T-shaped" load-bearing base. The pre-embedded 16 anchor bolts (Ø20mm) deeply anchor into the concrete structural layer, providing a pull-out resistance ≥120 kN, effectively preventing displacement of the manhole body. The unique tapered guiding structure ensures precise alignment between the cover and frame, with gaps controlled within 1mm, completely eliminating noise and bouncing during vehicle passage.  

3. Comprehensive Safety Protection System  

The product is equipped with a three-point heavy-duty concealed bolt lock, with the lock core achieving an IP68 protection rating and exceptional resistance to violent. The surface features deep herringbone anti-slip patterns with a depth of 5mm, providing a dry friction coefficient ≥0.65, ensuring reliable anti-slip performance even in rainy or snowy conditions. The split joint employs a labyrinth seal structure, effectively preventing tool insertion and comprehensively enhancing safety levels.  

4. Long-Lasting Anti-Corrosion and Durability  

The base material undergoes high-temperature hot-dip galvanizing treatment, with a zinc layer thickness ≥150μm, supplemented by an epoxy asphalt coating to form a dual protective barrier. Verified by 3000 hours of salt spray testing, the product remains intact in corrosive environments such as acid rain and de-icing agents. Key connection components are made of stainless steel, ensuring excellent performance even after 100,000 opening cycles.  

5. Smart Operation and Convenient Maintenance  

The product can be optionally equipped with an embedded RFID chip for digital asset management. The split-type design keeps the weight of a single cover within a reasonable range, eliminating the need for large machinery during maintenance and significantly improving operational efficiency. The modular structural design supports quick replacement, effectively reducing construction time and maintenance costs.  

The Luzhongbao 1200×740×60 split-type cast iron square manhole cover, with its innovative split structure, exceptional load-bearing performance, comprehensive safety protection, and long-lasting durability, sets a new industry benchmark for infrastructure protection in heavy-duty areas. The product has been successfully applied in multiple national key projects, earning widespread recognition for its stable quality and excellent performance, making it an ideal choice for the protection of large inspection shafts in modern urban construction.