8. Pipes and ducts

Large drinking water distribution mains can be made of reinforced cement, steel (which can be welded), cast iron, PVC or stoneware.

Numerous joint systems are available:

• bead and socket joints, formerly sealed with semi-rigid lead;

• flange gaskets ;

• ring or sleeve seals with a compressed rubber gasket ;

• flexible seals (e.g. Gibault type), sealed by a rubber ring;

• joints sealed with flexible elastomeric sealants (polyurethane, polysulphide, etc.);

• joints sealed with rigid epoxy sealants.

Of course, all products and materials in contact with drinking water must be safe for the consumer, and specific tests are available....