Material selection for chemical tanks is of prime concern when considering building costs, and maintenance costs.

This paper outlines why duplex stainless steels have been more and more selected instead of 316 LN or 317 LN grades for the erection of new chemical tankers.

The main advantages of duplex stainless steels, including their resistance to different corrosion mechanisms, their high mechanical properties which allows the designer to reduce weight when properly used, and their good weldability are emphasized.

The paper gives also some practical advices when selecting duplex stainless steels, i.e. how to specify and how to weld them. Finally, some practical experience gained from the use of the material in marine chemical tankers is summarised.