The fabrication of critical process equipment - and equipment for urea plants falls in that category - has always demanded specific expertise and skills from the part of the vessel fabricator. This because of the process conditions in urea plants, with high operating pressures in combination with corrosive process fluids.
In order to be able to successfully complete projects for such an environment, a number of requirements must be fulfilled, both from the customer and the vessel maker. This applies even more to the repair or modifications of such equipment considering the conditions in the field, in particular the time constraint for most of such works. This paper describes the fabrication sequence of HP urea equipment and specifically refers to the critical steps. It also highlights the special features of repairing or replacing liners as well as retubing in situ.