In municipal infrastructure, though small in size, manhole covers play a critical safety role. Hubei LuZhongBao's 700×800×120 ductile iron square-outer/round-inner cover stands out in the market with its unique design concept and outstanding performance, becoming the preferred solution for numerous engineering projects.
As urban construction evolves, requirements for municipal facilities have shifted from pure functionality to integrated functionality, aesthetics, and safety. Hubei LuZhongBao Metal Products Co., Ltd. deeply understands this trend, skillfully combining square-outer/round-inner design to ensure safety while achieving harmony with urban environments.
Unique Structural Design Features
The innovative square-outer/round-inner structure is deliberate:
- Square exterior minimizes gaps at pavement connections, reducing safety hazards
- Circular interior ensures the cover cannot fall into the manhole (equal diameters prevent misalignment)
This design avoids square covers falling diagonally while solving circular covers' poor pavement integration. The hybrid construction balances safety and aesthetics, reflecting deep understanding of practical applications.
Exceptional Material Advantages
Premium ductile iron with strict nodularization achieves spheroidal graphite, significantly enhancing mechanical properties:
- Tensile strength ≥420MPa, yield strength ≥300MPa (matching mild steel; 3× gray iron)
- Impact resistance similar to medium-carbon steel (10× gray iron)
- Superior corrosion resistance: 90-day corrosion mass is 1/40th of steel pipe and 1/10th of gray iron, with 2× gray iron and 5× steel pipe lifespan
Innovative Anti-Settlement Technology
Advanced anti-settlement design incorporates patented adjustable technology:
- Buffer mechanism prevents long-term impact sinking
- Coordinated settlement with road surface maintains flatness, eliminating bumps and hazards
- Four evenly distributed (90°) anchor bolt holes secure against mechanical displacement during road construction
Comprehensive Safety Assurance
Integrated safety features include:
- Vibration damping: U-groove with T-shaped rubber strips buffers impact forces
- Noise reduction: Eliminates "clanging" during vehicle passage
- Anti-theft: Outer square slots + inner locking mechanism prevents unauthorized removal
- Anti-slip: 3mm raised patterns ensure traction
- Displacement prevention: Anchoring system secures position
- Breakage resistance: Enhanced material durability
Practicality and Economic Efficiency
While initial costs exceed traditional covers, the product delivers significant long-term value:
- 30+ year design life with minimal maintenance
- Corrosion-resistant, pollution-free, and maintenance-free properties reduce municipal costs
- Easy installation and low upkeep further reduce lifecycle expenses
- Achieves dual economic and social benefits
Conclusion
The success of Hubei LuZhongBao's 700×800×120 ductile iron square-outer/round-inner cover stems from uncompromising attention to detail and quality. From innovative structure and material excellence to anti-settlement technology and comprehensive safety, every aspect reflects manufacturer dedication and expertise.
Choosing LuZhongBao means selecting not just a product, but assuming responsibility for urban safety and committing to public service. This is why increasing numbers of municipal departments and engineering contractors choose this innovative solution.