1. The primary materials used in manufacturing Ductile Iron Pipes, supplied by vendors certified under the ISO9002 system.

2. Internal corrosion prevention is achieved using a centrifugal method with cement sand slurry lining, requiring a smooth and even surface without cracks.

3. External corrosion protection is achieved through zinc spraying and asphalt coating, with zinc spraying adhering to the international ISO 8179 standard.

4. Ductile iron pipes should meet the safety evaluation standards for drinking water supply equipment and protective materials as specified in GB/17219.

5. Ductile Iron Pipe, length 6M, wall thickness K9 grade.

6. The quality requirements and testing methods for rubber rings should comply separately with the standard "ISO 4633-1996(E) - Gaskets for joints in water and drainage pipelines."