TPI July 2012

products & developments

Welding technology for potable water project The desalination of seawater, in order to provide potable water to those countries that have little of it, is a major challenge. The extremely high costs linked to the operation have previously obstructed the development of such a procedure. Using technology developed by the National Institute of Ocean Technology (NIOT), a low temperature thermal desalination (LTTD) facility in Agatti, Kavaratti – an island in the Indian Ocean – will produce potable water directly from the ocean, with low costs. The Indian government is monitoring the development of the project and its benefits, so as to expand the desalination technique not only to other islands, but to the entire Indian coast, with facilities that will produce 10mn litres of potable water per day. The desalination principle is based on a floating aspiration line. The ocean water has an average temperature of 28-30°C at the surface. In a vacuum chamber, the vapour obtained is condensed in sea depths of as much as 350-400m, where the temperature varies from 7 to 15°C. Not only can the system produce potable water at very low costs, but it can also generate energy, or even air conditioning. HDPE PE-100 pipes are used for this kind of job: OD 630mm for the aspiration pipes, and OD 315mm for distribution pipes. The pipes were dragged by boats to the island, and brought to dry in between the palm trees. At this scenic site, construction was assisted by a Delta 630 welding machine from Ritmo, Italy. The welder was equipped with a hydraulic crane that facilitated operations such as loading/unloading of the pipes, milling cutter, and heating plate. Considering the importance of the project, the contractor opted to have the welding certified by Ritmo’s Inspector, a data logger that analyses and saves the welding processes, and points out any errors occurring during the welding. The Inspector allows the storage of welding data, and printing of welding reports. Up to 1,020 saved reports can be managed directly from a PC/laptop, and a database can be created for future reference, by means of specific software. Having perfect and certified weldings at 400m under the sea is of the essence, as the pipes will bear extremely stressful conditions.

Ritmo SpA – Italy info@ritmo.it www.ritmo.it

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July 2012 Tube Products International