A water pipe is any pipe or tube designed to transport treated drinking water to consumers.

  The variants may include large diameter mains pipes which supply entire towns, smaller branch lines which supply a street or group of buildings, or small diameter pipes located within individual buildings. Water pipes range in size from giant mains examples of up to 144 inches (365 cm) in diameter to small 1/2 inch (12.7 mm) pipes used to feed individual outlets within a building. Materials commonly used to construct water pipes include polyvinyl chloride (PVC), copper, steel and, in older systems, concrete or fired clay.

  Joining individual water pipe lengths to make up extended runs is made possible with flange, nipple, compression or soldered joints.