In the vacuum system, sewage is transported by means of a vacuum. The water closets and other sanitary fittings are connected to a piping system, which is maintained under partial vacuum, through valves that are normally kept closed. The vacuum is generated by one or several vacuum pumps situated at the outlet end of the system. The amount of water used is only 1.2 litres per flushing and so the vacuum system achieves a significant saving in water consumption. The vacuum system can be connected via a special discharge unit to any receptacle under atmospheric pressure. The holding tank can be freely designed with regard to the available space, or an existing space in the ship's structure may be used as an integral holding tank. The discharge from the holding tank can be connected to a sewage treatment plant if the intended route of the vessel is mainly in areas where discharge of untreated sewage is not permitted. In this case a vacuum tank is unnecessary and a special discharge unit would be provided. Owing to the reduction in the volume of the sewage, the treatment plant need not be over-dimensioned to cope with an unnecessary amount of diluted waste water.

  • Corporate Authors:

    Whitehall Technical Press Limited

    29 Palace Street, Westminster
    London SW1,   England 
  • Publication Date: 1976-12

Media Info

Subject/Index Terms

Filing Info

  • Accession Number: 00168298
  • Record Type: Publication
  • Source Agency: Engineering Index
  • Files: TRIS
  • Created Date: Mar 29 1978 12:00AM