Case story: Sandvik's urea stripper tubes set world record
Sandvik 2RE69 tubes set a world record after operating for 36 years in the CO2 stripper of a large European urea plant.
A leading European ammonia and urea producer built its three CO2 stripping urea plants in the mid 1970's with the aim of operating them continuously over many years. To ensure long service life, the plants were designed with Stamicarbon's innovative and efficient urea stripping technology based on reduced steam consumption.
Since the stripper is a very critical part of the urea process, tough demands were put on the tube material that must be able to resist the severely corrosive environment and high temperatures.
The Sandvik solution
Maximizing CO2 stripper service life requires high-performance tubes meeting the very tough demands on corrosion resistance and extreme care in fabrication and operation of the plant. For this reason, two of the strippers were fabricated using Sandvik 2RE69 tubes.
This high-alloy grade with almost zero ferrite content was developed specifically for the most severe conditions in the urea production process.
The two strippers with Sandvik 2RE69 tubes were replaced after 34 and 36 years operation. The tube material has thereby set a world record on-stream time for any high-pressure stripper in a urea plant, resulting in exceptionally low lifecycle costs. The previous longest service record for Sandvik 2RE69 was 27 years.
High-pressure equipment items in the plants are currently being manufactured using material grade Safurex – the successor to Sandvik 2RE69 and specially developed for the urea industry through close cooperation between Sandvik and Stamicarbon.
The exceptional corrosion resistance of Sandvik 2RE69 and Safurex has made Sandvik the global market leader in tubes and complementary products for urea production.