#main  a principal pipe in a system that distributes water or gas or electricity or that collects sewage
  supertype:  pipe__pipage__piping  a long tube made of metal or plastic that is used to carry water or oil or gas etc.
  subtype:  electric_main  gas_main  sewer_main  water_main
  part of:  infrastructure__base  the stock of basic facilities and capital equipment needed for the functioning of a country or area; "the industrial base of Japan"

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