Water mains represent the largest single investment in a distribution system. Water mains have long service lives; some mains are more than 100 years old and still have service life left. Water system piping can generally be divided into two classes -- transmission mains and distribution mains. In this DVD, distribution employees learn about the many types of pipe currently in use: cast iron, ductile iron, steel, concrete, asbestos-cement, PVC, PE, and fiberglass. They learn the advantages and disadvantages of each pipe type, and its internal pressure and external load ratings; installation practices, bedding and support, joining, fittings, and tapping; pipe handling safety; causes of internal and external corrosion, corrosion protection, pipe rehabilitation, repair, and linings; pipe inspection techniques, maintenance, and recordkeeping.