1. Documentation Verification

• Mill Test Reports (MTRs):
  New ductile iron pipes should come with a certificate of compliance or a mill test report from the manufacturer. This document confirms the chemical composition, mechanical properties (e.g., tensile strength, elongation), and compliance with standards like ISO 2531, EN 545, or AWWA C151.

• Material Certificates:
  Check for certifications such as ISO 9001 (quality management) or ISO 14001 (environmental management), which reputable manufacturers adhere to.

• Traceability:
  New pipes will have batch numbers, heat numbers, or casting marks to trace the production process.

2. Visual and Surface Inspection

• Surface Finish:
  New ductile iron pipes typically have a smooth, uniform surface. Look for:

  • Protective Linings/Coatings: New pipes are often coated with zinc (external) and cement mortar or polyethylene (internal) to prevent corrosion. These coatings should be intact and free of cracks or peeling.

  • No Rust or Corrosion: New pipes should lack significant rust, pitting, or old repair marks.

• Markings:
  Check for stamped or painted markings on the pipe:

  • Manufacturer’s name or logo.

  • Production date (new pipes will have recent dates).

  • Compliance with standards (e.g., "EN 545" or "ISO 2531").

  • Nominal diameter and pressure class (e.g., "DN600, PN16").

• Joints:
  New pipes have clean, undamaged joints (e.g., push-on, flanged, or mechanical joints) without signs of prior use.

3. Material Testing

• Chemical Analysis:
  Use spectrometry or laboratory testing to verify the chemical composition. New ductile iron should contain:

  • Carbon (3.0–3.9%)

  • Silicon (1.5–3.0%)

  • Magnesium (0.02–0.1%) (for nodular graphite formation).
    Low levels of impurities (e.g., sulfur, phosphorus) indicate higher-quality new material.

• Mechanical Testing:

  • Tensile Strength: Should exceed 420 MPa (per ISO 2531).

  • Elongation: ≥10% (ensures ductility).

  • Hardness: Typically 130–200 HB (Brinell hardness).

• Microstructure Analysis:
  A metallographic exam under a microscope should reveal nodular graphite (spheroidal structure), not flake graphite (indicative of inferior cast iron).

4. Non-Destructive Testing (NDT)

• Ultrasonic Testing:
  Detects internal flaws (e.g., voids, inclusions) common in recycled or poorly cast pipes.

• Magnetic Particle Inspection:
  Identifies surface cracks or defects.

• Thickness Measurement:
  Use ultrasonic gauges to ensure consistent wall thickness (varies by pressure class).

5. Supplier Reputation and History

• Purchase from reputable manufacturers or distributors with a track record of supplying new DI pipes.

• Avoid suppliers offering "discounted" pipes without proper documentation.

• Verify if the supplier follows industry standards (e.g., Ductile Iron Pipe Research Association (DIPRA) guidelines).

6. Field Observations

• Weight: New ductile iron pipes are heavier than many alternatives (e.g., PVC) but lighter than old cast iron.

• Sound Test: Tap the pipe—new ductile iron produces a clear, metallic ring, while damaged or corroded pipes sound dull.

Key Red Flags for Recycled/Used Material

• Faded or missing markings.

• Uneven coatings, rust, or weld repairs.

• Inconsistent dimensions or wall thickness.

• Lack of certification or vague documentation.