1. Pipes and ducts

1.1 Materials

The steels used to manufacture pipes for building and industrial networks can be :

• Black" steel: this is a mild steel whose hot fabrication gives it a surface oxidation. This surface layer of black iron oxides gives it its common name. This layer of scale, which adheres poorly to the underlying metal, peels off as soon as it is put into service. Different grades are available to suit different temperatures and pressures.

• Galvanized steel: generally used for pipes conveying water for human consumption (cold and hot sanitary water) in installations...