管子，是一种中空圆柱物体，用来输送流体。

• 金属
  • 铸铁、碳钢、不锈钢
  • 铜、黄铜、铝、铅
• 热固性塑胶
  • 玻璃钢（GRP）
• 热塑性塑胶
  • PE、PVC、ABS
• 混凝土
• 玻璃

A pipe is a tubular section or hollow cylinder, usually but not necessarily of circular cross-section, used mainly to convey substances which can flow — liquids and gases (fluids), slurries, powders and masses of small solids. It can also be used for structural applications; hollow pipe is far stiffer per unit weight than solid members.