SUCCESSFUL USE OF STAINLESS-STEELS IN NITROGEN-BASED FERTILIZER PLANTS

In ammonia plants duplex stainless steels have been successfully used in many heat exchangers operating up to 600 degrees C in cooling water polluted by chlorides. The duplex stainless steels offer a safe and c ost-efficient alternative to carbon steel and stainless steels in the 300 series. In urea plants operating with stripper technology the mate rial for the stripper condenser, H.P. piping and reactor is reviewed. The good performance of 2RE69 has lead to a wider usage especially whe n 316L Urea Grade has been replaced for the Snamprogetti stripper. The new bimetallic tubing using a 2RE69 tubing with an inner lining of zi rconium is now an accepted solution. Welding consumables are also pres ented.