How to Identify Ductile Iron Pipe Uses by Color: A 5-Minute Guide

1. Basic Principles of Ductile Iron Pipe Color Coding

Ductile iron pipe color coding is a visual system rooted in functional and safety requirements. Standards like ISO 7346 and ASTM A153 define colors for specific applications:

• Blue typically marks municipal water supply pipes.

• Red is used for high-pressure or high-temperature environments, such as gas pipelines in energy facilities.
  Industry practices further align colors with Material Application Codes, ensuring compatibility with coating properties like corrosion resistance and pressure tolerance.

2. Common Colors and Their Functional Applications

Black: General Drainage Systems

Black ductile iron pipes are ideal for general drainage systems, offering cost efficiency and compatibility with non-corrosive environments.

Red: High-Pressure/High-Temperature Scenarios

Red pipes are designed for energy and power equipment . Their epoxy resin coatings withstand temperatures above 150°C, making them suitable for steam or gas transmission.

Blue: Global Standard for Water Supply

Blue is the universal identifier for municipal water supply pipes, adhering to ISO 7346 drinking water safety guidelines.

Green: Corrosion-Resistant Industrial Use

Green pipes serve harsh environments like chemical plants and marine engineering projects . Their zinc-aluminum coatings provide long-term protection against saltwater and chemical exposure.

Custom Colors: Specialized Identification

Custom colors (e.g., orange for fire safety) address niche needs . These pipes often require coordination with suppliers to meet project-specific standards.

3. Practical Use Cases in Engineering Projects

In underground pipe installation, color coding minimizes errors during excavation. For example, blue pipes are prioritized in municipal projects.. Maintenance teams also rely on Pipe Identification Systems to locate faults in multi-color networks.

4. How Colors Reflect Coating Performance

Colors directly correlate with coating technologies:

Red epoxy coatings resist high temperatures and insulation demands, ideal for energy systems.

Silver zinc-aluminum coatings (on green pipes) meet ASTM A153 standards for corrosion resistance, ensuring durability in marine environments.

5. Procurement Tips: Matching Colors to Specifications

Verify Supplier Certifications: Always request ASTM/ISO compliance documents.

Bulk Order Optimization: Clarify Bulk Order Color Requirements with suppliers to ensure production consistency and avoid delays.