#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.
  part of:  infrastructure
  subtype:  electric_main  a main that distributes electricity
  subtype:  gas_main__gasmain  a main that distributes gas
  subtype:  sewer_main__sewermain__sewer_line__sewerline  a main in a sewage system
  subtype:  water_main__watermain  main (a pipe or conduit) for conveying water

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