Coatings for ductile cast-iron pipes

Coating technology

Coating technology

Exterior protection for extreme durability

Ductile cast-iron pipes are renowned for their exceptional durability.
The various external coatings we use are a major factor in ensuring that our pipes go the distance.

Pipe with zinc coating

Zinc coating with polymer-modified cement-mortar coating (CMC)

Pipes with a polymer-modified cement-mortar coating can be placed in soils of any level of aggression with a maximum grain size of 100 mm.  This exterior coating is available for pipes with nominal sizes from DN 80 to DN 1000.

Polyurethane coating (DIN EN 15 189)

The PUR coating (vonRoll ECOPUR) is a reinforced coating (fully protected pipe) in accordance with EN 545. The coating is a passive protection system. It acts as a barrier between water (or the soil) and ductile cast iron, and is resistant to aggressive, acidic and heterogenous soils. We offer PUR-coated pipes in nominal sizes from DN 80 to DN 700.


Zinc-aluminium coating with epoxy resin finishing layer (Duktus Zinc-Plus)

This exterior coating is comprised of a Zn/Al alloy applied at a mass of 400 g/m². It is suitable for use in combination with soils with a grain size of up to 32 mm. The zinc-aluminium exterior coating is available for pipes with nominal sizes from DN 80 to DN 1000.

Galvanising a pipe

Zinc coating with epoxy resin finishing layer

Available in nominal sizes DN 80 to DN 1000. Suitable for use in soil classes I and II in accordance with DIN 50 929, Part 3 (mildly aggressive and aggressive). If used in conjunction with a corrosion-protected bed, where the location permits, also suitable for use in soil class III (highly aggressive). Maximum round grain size of 32 mm.

Thermal-insulated compensator (WKG) pipes

WKG pipes

Thermally insulated pipes made from ductile cast iron for drinking water supply and waste water disposal in insulated frost-sensitive pipes (WKG).

The CFC-free polyurethane (PUR) hard foam insulation protects drinking water and waste water pipes, as well as the connected socket bends in applications such as bridge pipelines, against the cold. It can also be used to protect above-ground pipelines and pipelines installed just below the surface.

Even in severe sub-zero conditions, water or waste water can remain in the pipes for long periods of time without freezing.

In abouve-ground pipelines, the PUR hard foam is protected against weather conditions by a wrapped galvanised steel or stainless steel coating.

Buried pipelines are equipped with a polyethylene coating.

The standard socket joints are also available for WKG pipes.

Other coatings are available on request.

Internal coating for hygienic operating methods

Depending on their application or the medium with which they are to be used, ductile cast-iron pipes come with different cement-mortar linings:

Blast furnace cement mortar (BFSC) for drinking water supply

  • Inorganic lining ideal for transporting drinking water
  • Centrifugal casting process for extreme wear-resistance and durability

High alumina cement mortar (HACM) for waste water disposal

  • Flow speeds of up to 20 m/s can be achieved
  • Used for domestic waste water with a pH value between 4 and 10

High performance mineral (HPM) for special applications

Duktus offers a range of highly reliable, wear-resistant internal coatings for industrial applications (e.g. mining, potassium & salt) to protect pipelines against abrasive and aggressive liquid media.

Compared to other pipe materials and coatings, Duktus pipes coated with HPM have a significantly longer operating life. The HPM coating can withstand significant frictional force in combination with low pH values, and is an active protection system.

Polyurethane coating in accordance with DIN EN 15 655

  • Universal application: Drinking water, waste water, natural gas
  • pH value between 1 and 14

Other internal coatings are available on request