La description

Foam fire suppression systems are used primarily to protect hazards or areas with flammable liquid fire hazards. The fire extinguishing foam is made from missing foam concentrate and water within the piping network. The foam extinguishes fire by smothering the fire, suppressing flammable vapor production, and cooling the fuel in adjacent areas.
The specifications for piping material that carries foam concentrate and solution must be closely coordinated with the recommendations of the foam manufacturer. Often stainless-steel piping is recommended. Selecting an inappropriate piping material may increase maintenance needs on the system and decrease the piping usable service life.