State of the art

European shell and tube heat exchangers market is undergoing a phase of cutthroat competition, which is adversely affecting the margin of domestic companies. Low cost heat exchanger suppliers from outside Europe have been fuelling the aggressive price war. Foreign entrants include suppliers from South Korea, China, and India as well. Surging metal prices and energy costs are also having a direct impact on profitability of heat exchanger manufacturers in Europe. Although companies are devising strategies to sustain their markets, pricing pressure is expected to continue in future.


Productivity improvements in the heat exchangers manufacturing are set to revitalize the shell and tube exchangers market. Indeed, the welding process plays a significant role in order to reduce the production cycle time, and thus reducing the delivery time, especially in shell and tube heat exchangers, where thousand of tube to tube-sheet welded joints are required. The orbital arc welding process for welding tube to tube-sheet joints was one of the major improvements introduced in this industrial sector in 1980s.

This process is well established in different industrial sectors due to the high quality of the welded seams and the good repeatability of the process. The orbital arc welding process is an alternative to manual arc welding process because it increases the welding speed and ensures the repeatability of the welded seams. Even so, the cycle time of the welding process is still very high, typically around forty seconds.

Tube to tube-sheet TIG welds 

The introduction of laser welding for the manufacturing of heat exchangers and steam generators can introduce some improvements in the manufacturing process such as the increase of the welding speed and therefore a reduction of production time. Furthermore due to the large number of welds to be done, the time between each operation is a critical point. The automation of the process, involving the use of the laser welding technology, would permit to reduce the time between welding operations. On the other hand, one of the main characteristics of laser welding is the high focused energy, allowing to get high power density in a spot size of 0,2-0,6mm. It results in a narrow fusion zone and low heat input so a reduction of rework operations can be expected decreasing the costs of rework, maintenance and repair of welded parts. As a result, the production cycle time would be reduced, improving productivity.

Orbital laser weld on stainless steel

 inox_tubo_6  inox_tubo_6_p1.5_v1.5_f-2_97471-15_fig_7a

Orbital laser weld on Inconel alloy

inconel_tubo56_p1.5_v3.5_f-0.5_97471-19_fig_1  inconel_tubo57_p1.5_v4_f-0.5_97471-18_fig_2a



The research leading to these results has received funding from the European Union Seventh Framework Programme (FP7/2007-2013) under grant agreement n° 262455