I. Technical Features
The Ductile Iron Adjustment Ring is a critical transition component installed between the manhole chimney and cover, ensuring perfect road surface alignment through precise height leveling. It addresses three key engineering challenges:
1. Settlement Compensation:Elevates covers via ring stacking when roadbed settlement occurs, eliminating chimney reconstruction.
2. Construction Error Correction:Allows ±50mm height adjustment to rectify chimney casting elevation deviations.
3. Multi-Material Compatibility:Adapts to asphalt, concrete, brick, and other pavement structures.
II. Core Advantages
(1) Precise Elevation Adjustment
- - Wide Adjustment Range:
- - 20-150mm height adjustment (5 grades, ±0.5mm precision per grade), suitable for road milling and overlays.
- - 360° rotatable ring (with scale markings) enables single-person leveling in 10 seconds—20x faster than concrete bedding.
- Anti-Settlement Design:
- - Serrated base anchors (depth ≥30mm, grip ≥15kN) prevent displacement under vehicle loads.
(2) Military-Grade Structural Strength
- Material & Process:
- QT500-7 ductile iron: Compressive strength ≥400MPa (4x higher than C30 concrete).
- Reinforced Structure:
- Annular ribs (12mm thick) + radial stiffeners (8 units, 20mm height) distribute load stress.
- Load Certification:
- Passes EN124 D400 test (400kN static load, deformation <0.15mm).
- Compatible with 40-ton covers; fatigue resistance >2 million cycles (75kN cyclic load).
(3) Rapid Installation & Maintenance
- Modular Design:
- Snap-lock pins (304 stainless steel) enable installation ≤3 minutes/unit (vs. 2 hours for concrete pouring).
- Immediate traffic readiness reduces road closure time by 90%.
- Reusability:
- 100% intact after disassembly, suitable for multiple road renovations (concrete bedding requires demolition).
III. Application Scenarios
- Road Renovation:
- Beijing Chang’an Avenue overhaul (5,000 units saved 30 days).
- Soft Soil Settlement Zones:
- Shanghai Pudong Airport runway (cumulative adjustment: 120mm, zero displacement).
- Smart Cover Systems:
- Shenzhen Smart Roads (rings pre-equipped with tilt sensors for real-time settlement monitoring).
IV. Technical Standards & Certifications
- International Standards:
- EN124 (Cover Load-Bearing)
- ISO 1461 (Hot-Dip Galvanizing)
- China Standards:
- GB/T 23858-2009 (Manhole Covers)
- CJ/T 327-2010 (Recycled Water Drainage Grates)
- Special Certifications:
- SGS Salt Spray Test >3,000 hours
- EU CE-CPR Certification (Class A1 Fire Resistance)
Summary
Ductile iron adjustment rings redefine road elevation control through millimeter-level leveling, lifetime maintenance-free operation, and heavy-load compatibility:
1. Leveling Revolution:20-150mm stepless adjustment, 10x more precise than concrete bedding!
2. Economic Dominance:Zero maintenance for 30 years; total cost = 18% of concrete solutions.
3. Smart Integration:Optional sensors enable settlement warnings, extending road lifespan by 50%.
> Engineering Selection Guide:
> - Standard Roads: QT500-7 base model (50mm adjustment)
> - Soft Soil/Frost Zones: Deep anchor version (anchor depth ≥50mm)
> - Smart Projects: Mandatory tilt-monitoring module (±0.1° precision)
