TPi September 2014

products & developments

Plant extends tube life to 15 years A major Caribbean producer of furfural, an organic compound derived from agricultural by-products, chose to replace the existing tube in its heat exchangers with hyper-duplex stainless steel by Sandvik Materials Technology. As a result, its tube lifecycles have extended from two to 15 years, with an impact on material costs. Sandvik SAF 2707 HD is a hyper-duplex stainless steel with resistance to pitting corrosion and chloride induced stress corrosion cracking.

The material is an alternative to nickel alloys with similar performance, but according to Sandvik is more attractive economically in terms of material and life cycle costs.

The furfural plant, based in La Romana, the third-largest city in the Dominican Republic, was experiencing problems with the lifecycles of existing standard stainless steel tube in several of its heat exchangers, used to process untreated seawater as the cooling media. In some cases the existing tube needed replacing after just two years. A new material was therefore required that would better withstand exposure to seawater with sewage load, microbiological influenced corrosion (MIC) and sulphur ions, with lower costs for the customer. The plant gradually upgraded the quality of its tube, and in 2008 Sandvik SAF 2707 HD ® tubes were installed in two overhead heat exchangers. Replacement material was installed in a distillation column that condenses furfural acid and low boiling components.

“Our hyper-duplex stainless steel was selected for its mechanical

has a presence in the western market. In addition to the domestic market, Nezone’s products have been accepted in countries including Australia, Singapore, Sri Lanka, Bangladesh, Nigeria and Canada. Nezone Tubes Ltd and Nezone Strips Ltd have received various export excellence awards from Engineering Export Promotion Council for Exporting, and the Nezone Group has been recognised by the Government of India as an ‘Export House’. The manufacturing facilities of the companies are located around India, including the eastern region, north- eastern region and southern region. Mr Senatore added, “Sandvik SAF 2707 HD is helping to increase service life and reducing maintenance in many types of heat exchangers. “The material is a cost-competitive alternative to standard grades by minimising risks and outperforming Super Duplex stainless steels. The customer now expects a tube life of 15 years minimum. This increased service life from two to 15 years will have a profound impact on material costs.” Sandvik Materials Technology – Sweden www.smt.sandvik.com

strength, that is higher than all Super Duplex stainless steel grades available on the market, and excellent chloride corrosion resistance suited to much more aggressive service conditions,” explained Marcelo Senatore, global technical marketing, Sandvik Materials Technology. After two years of successful operation, the heat exchangers were inspected and found to be as good as new, showing no signs of pitting corrosion. The furfural producer will introduce periodic washing of metal surfaces to keep the equipment free from seawater debris.

Electric-welded steel tubes The Nezone Group is a multi-plant manufacturer, specialising in the production of electric-welded steel tubes. Starting with electric resistance welded (ERW) steel tubes, both black and galvanised, of different dimensions, the group has extended its capabilities to manufacture cold rolled and cold rolled close annealed strips, precision tubes, hollow steel sections (RHS/ SHS), air pre-heater tubes (ERW), OD series pipes for idlers and oval tubes. Only top quality steel is purchased from leading primary producers. Most of the manufacturing units of the group have been awarded ISO 9001:2008 certification from reputed accrediting agencies. The group states that it has a position of prominence in the eastern and north- eastern region of India, and that the products of the group companies are regularly purchased by different state public health engineering departments, irrigation departments, railway, defence, telecom companies, automobile manufacturing units, bus/crane earth- moving manufacturing units, and different government/semi-government infrastructure companies. Founded in 1981, Nezone is now a ‘one-stop shop’ for all welded steel tubes. The Nezone Group operates fully integrated manufacturing facilities, allowing it to keep a stringent check at every stage, from examining the quality of raw materials procured to slitting, tube formation, sizing, annealing, galvanising, fabrication and packing. The group has a distributor and dealership network in the north-eastern, eastern and southern regions, and also

Nezone Tubes Ltd – India nezone@nezonesteel.com www.nezonesteel.com

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September 2014 Tube Products International