Ductile iron pipes - Solutions for drinking water and raw water

In France, and in most countries around the world, water networks (transport, conveyance and distribution of drinking water and raw water) are mainly made up of cast-iron components: grey cast-iron for the oldest and especially ductile cast-iron for those laid since the 1960s and today.

The mechanical performance of ductile cast iron is high, similar to that of steel. The ability of ductile cast iron to be precision-molded using a foundry process, combined with its superior resistance to corrosion, enables the efficient production of a wide range of high-performance components for water networks. As a result, contractors can build homogeneous networks covering diameters from 60 to 2,000 mm, drawing on the full range of components on offer. The components are very diverse, including pipes (socket, flange), fittings (elbows, tees, reducers, solid plates, etc.) and accessories (flanges, counter-flanges, locking devices, etc.). Fittings for water networks are also manufactured in ductile cast iron.

Ductile iron pipes are manufactured using the centrifugal casting technique, by pouring liquid cast iron into water-cooled rotating metal molds. Fittings are made by casting in sand molds.

Product quality is ensured by compliance with standards and additional specifications specific to each manufacturer. The manufacturer must set up a quality assurance system based on a quality management system ( NF EN ISO 9001 ), rigorous performance testing and monitoring of the manufacturing process.

Standards play an important role, particularly in the context of public tenders. European (EN) and international (ISO) standards, which specify the essential characteristics of ductile cast iron pipe components, are presented in detail. These standards have evolved significantly since the 2000s, incorporating more functional and performance characteristics.

All pipe components consist of a ductile cast-iron mechanical structure protected by coatings. This structure provides resistance to operating pressure (up to 100 bar), earth and rolling loads, shocks, ground movements, etc. This high level of resistance, thanks to the use of ductile cast iron and the safety coefficients used in design, means that they can cope with the many hazards of use, and is much appreciated by project owners.

Cast-iron components are marketed with protective coatings that enable them to be used in all contexts, over and above the intrinsic performance of the cast-iron material. Exterior coatings provide long service life in all types of flooring. Active coatings, currently based on zinc and aluminum alloys, are used for everyday situations. Passive...