The high-pressure vessels in the new Assaluyeh urea production plant in Iran are being constructed in Sandvik Material Technology’s recently developed Sandvik SafurexTM steel grade. All stainless steel materials for high-pressure equipment are being supplied by Sandvik. Although Sandvik Safurex materials have been installed, tried and tested in several plants around the world, the Assaluyeh plant is the first green field site where Sandvik Safurex is introduced as the preferred steel grade for use in all high pressure equipment, throughout the stripper, pool condenser, reactor and scrubber. Developed in co-operation with Stamicarbon, Sandvik Safurex has many advantages over other steel grades for urea service but, in particular, has the ability to passivate at a lower oxygen level. It therefore has the key benefit of reducing the level of oxygen content in the process. With the injection of less oxygen in the form of air, there is less inertia in the system, contributing to increased manufacturing capacity. Sandvik Safurex also has the benefit of extremely high strength and the risk of high corrosion rates in considerably reduced. It also has improved resistance to stress corrosion cracking. Due for delivery in 2003, the Assaluyeh pressure vessels are due for fabrication by summer 2003.
