Major Products in Municipal Engineering Castings

Major Products in Municipal Engineering Castings

In municipal engineering, the main casting products include the following:

Manhole Covers and Drainage Grates

Usage: Used for covering and protecting road drainage systems, sewers, and inspection chambers.

Pipeline System Castings

Examples include ductile iron pipes, fittings, and valves, primarily used for water supply, drainage, and gas transmission.

Guardrails and Lamp Post Bases

Usage: For road and bridge safety protection and aesthetic purposes.

Trench Covers and Cable Duct Supports

Usage: Used to cover drainage ditches and support cable ducts.

Key Raw Materials and Their Requirements

Pig Iron (Gray Iron or Ductile Iron)

Gray Cast Iron: Mainly used for standard manhole covers and drainage grates, requiring high compressive strength and good fluidity.

Ductile Cast Iron: Used for load-bearing manhole covers, pipes, and valves, requiring high strength and ductility.

Requirements:

Stable chemical composition, with carbon and silicon content meeting design specifications.

Ductile cast iron should have good spheroidization, with a spheroidization grade of 1-3.

Impurities such as sulfur and phosphorus must be strictly controlled to avoid affecting mechanical properties.

Steel

Used in certain high-performance guardrails, lamp post bases, etc., requiring good corrosion resistance and high strength.

Other Additives

For example, wear-resistant additives, graphitization promoters (for gray cast iron), and nodulizers (for ductile cast iron).

Finished Product Standards

Manhole Covers and Drainage Grates

Standards:

EN 124-2 (European Standard): Classified into six load-bearing classes: A15, B125, C250, D400, E600, and F900.

Chinese Standard (GB/T 23858-2009): Classified into light, standard, and heavy-duty grades.

Requirements:

Smooth surface without obvious defects (e.g., pores, cracks).

Tight fit between the cover and frame to prevent displacement or noise.

Pipes and Valves

Standards:

ISO 2531: International standard for ductile iron pipes and fittings.

GB/T 13295-2013: Chinese standard for ductile iron pipes.

Requirements:

Internal and external anti-corrosion treatment to prevent rusting.

Excellent sealing performance with no leakage.

Guardrails and Lamp Post Bases

Standards: Must comply with urban construction or traffic safety standards (e.g., GB 5768-1999 for road signs and markings).

Requirements:

Surface coated with anti-rust layers for strong weather resistance.

Adequate strength and impact resistance to meet engineering needs.

Trench Covers

Standards: Must meet requirements for compressive strength, wear resistance, and anti-slip performance.