“The pipes with the red cap!” and their characteristics:

FW pipe bearing with red caps in Celle
FW pipe bearing with red caps in Celle
  • Suitable for use both below and above ground
  • Suitable for use in all types of soil
  • Testable at any time
  • Usable under any operating conditions
  • Safe in case of flooding
  • Usable for any media as the material of the inner pipe can be adapted
  • FW STEEL-CASED PIPE-IN-PIPE is operated with vacuum in the ring space because:
      - thermal losses are reduced by up to 50%
      - the tightness of the system is permanently controlled 
      - by the removal of oxygen and humidity the external side of the inner pipe and 
        the interal side of the encasing pipe is permanently protected from corrosion.
  • Equipped with cathodic corrosion protection (where electrical ground resistance is ≤ 10,000 Ohm cm)
  • Offers a high degree of prefabrication. All fittings such as elbows, anchors, watertight wall ducts, axial compensator end seals, T-junctions, reductions, pipe bearings, compensators, etc. are installed in or on the 12 - 16 metre long construction units at the factory.
  • Both the encasing and the inner pipe are welded so as to be pressure-resistant and vacuum-tight
  • FW STEEL-CASED PIPE-IN-PIPE- anchors do not need concrete foundations
  • The steel-cased pipe-in-pipe, firmly installed in the ground, absorbs soil and traffic loads; the inner pipe is free to expand when exposed to heating
  • Inner pipes can be thermally pre-stressed against the encasing pipe; this enables long routes to be built without compensators



  • Northern Italy: laying of FW STEEL-IN-STEEL-PIPE systems, above ground on a steep slope

  • Horizontal directional drilling – the fascinating, sheer aesthetics of mud


  • FW-SIS with passive corrosion protection made of polypropylene

  • Prefabrication

  • Standard length production: metal strapping of insulating shells

  • Horizontal directional drilling – the aesthetics of mud and Strasbourg on water - 7.000 m FW-SIS

  • Amsterdam

  • Memorial Church in Berlin