F900 Airport Ductile Iron Manhole Cover

F900 Airport ductile iron manhole cover is a super heavy-duty ductile iron manhole cover designed for extreme wheel loads, primarily used in airport runways, military facilities, and ports. It meets the highest load-bearing class F900 (900kN test load) in the European EN124 standard.

Ductile iron manhole covers are classified into 6 load-bearing grades according to the EN124 standard. The main differences are as follows:

F900 Airport Ductile Iron Manhole Cover: 90-ton ultra-heavy load capacity, engineered for extreme airport runway conditions-safe, durable, and reliable protection for critical infrastructure!

A. Complete drawing design per F900 grade standards, airport application needs and EN specifications, confirmed by the customer and technical team.

B. Manufacture cast iron/high-strength sand molds (15-20 days) and conduct mold tests to verify dimensional accuracy and forming effect.

C. Prepare pig iron and high-quality scrap steel, proportionally blend raw materials meeting ductile iron requirements.

D. Melt raw materials at 1450-1500℃, add nodulizers to spheroidize graphite and improve material strength and toughness.

E. Pour nodularized molten iron into preheated molds at a uniform speed, control temperature for solidification to form manhole cover blanks.

F. Separate blanks from mold sand via vibration shakeout, clean residual sand, risers and flash.

G. Perform shot blasting to remove surface scale and impurities, grind to correct dimensional deviations for a smooth surface.

H. Apply epoxy resin or zinc coating by spraying/dipping to form an anti-corrosion layer isolating corrosive media.

I. Conduct load-bearing, material, dimensional/appearance and defect tests, reject non-conforming products.

J. Package with wooden boxes/pallets + cushioning materials, arrange logistics delivery to the designated location as per order requirements

Visual Inspection: Check for surface defects (cracks, pores, sand holes) with magnifying glasses (≥10x);​
Dimensional Testing: Use a coordinate measuring machine (CMM) to verify key dimensions (cover diameter, flange thickness, anti-slip groove depth) against EN 124 standards;​
Mechanical Testing: Sampling test-tensile test (tensile strength, elongation), impact test (-20℃ impact energy ≥20J);​
Load Testing: For F900 covers, apply 900kN vertical pressure (1.2x rated load) for 1 hour, no permanent deformation or cracking allowed;
Coating Testing: testing coating appearance (no runs, bubbles, etc.), thickness (DFT ≥80μm), adhesion (grade ≤1), corrosion resistance (no red rust in 500-hour salt spray) and drying performance (tack-free time ≤2 hours) to ensure its corrosion resistance and durability.