Ductile iron pipes for highly aggressive soils

STANDARD All Terrain or TT (“Tous Terrain”) ductile iron pipes are protected by an exterior coating that is suitable for extremely corrosive soil in which a zinc coating is no longer sufficient.

The pipes come in two types according to the diameter - PE or PUX:

  • For diameters between DN80 and 700 mm: TT PE pipes, coated with a 2 mm layer of extruded polyethylene over a BioZinalium coating (conforming to standard EN 14628)

  • For diameters between DN800 and 2000 mm: TT PUX pipes, coated with a 1 mm layer of polyurethane thermally sprayed onto shot-blasted ductile cast iron (conforming to standard EN 15189)

The fittings for these pipes have a thick epoxy external coating for the small diameters and a polyurethane coating for the larger ones. The range of application of coatings is specified in Annex D of standard EN 545.


  • Tried and tested: in addition to rigorous tests performed in the laboratory, the coatings on pipes laid in the aggressive marine soil of the bay of Mont Saint Michel in France have been observed over a very long period, demonstrating their efficiency and longevity. They have also been tried and tested in the large Taweelah and Shuweihat projects in the salt deserts of the United Arab Emirates.
  • On-site support: the PAM expert technical teams can conduct soil surveys on request to establish which ductile iron pipe solution is most appropriate in the given geographical terrain and work site conditions.
These PAM technical teams can conduct soil surveys as per the customers’ request.
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Aggressive soils

Ductile iron pipes and coatings for withstanding corrosion 

Underground pipelines are subject to a variety of stresses, including corrosive soils and backfills. The conventional zinc coating on the basic version of our pipes provides a high level of resistance to corrosion in most standard cases of application.

However, the soil’s corrosiveness must be assessed to determine whether additional active protection, such as a polyethylene sleeve or special coating, is required. This can be done by means of a topographical survey by our expert technical staff, which evaluates the various strata traversed and provides information on the nature of the terrain and its natural corrosiveness.  

Saint-Gobain PAM has developed special coatings made of a zinc-aluminum alloy, BioZinalium, to ensure the longevity of its ductile iron underground pipes.

TT PUX in aggressive soil
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See also

Ductile iron pipes with special coating for withsatanding corrosion