With an increasing number of  urea plants  becoming older or even reaching the end of their design life , and thus the  installed  equipment, the need of more intensive attention directed to these equipments has become bigger. Unscheduled shutdowns as a result of failed equipment can be costly or disastrous at worst. Therefore plant operators need to establish
thorough inspection and maintenance programs in order to be able both to monitor the integrity of installed items and to take corrective actions in case of problems. These programs must address the  concept of preventive maintenance as well as quick response to emergency situations.
In those cases when equipment needs to be repaired , the decision must be made whether such repair should be carried out in a shop or could be also made in-situ. In those instances when such a repair is not technically feasible or economically justified and the equipment must be replaced, then the replacement  of equipment within an acceptable time frame becomes important.
This paper describes projects of replacing old equipment with new ones on one hand and the execution of an in-situ repair of a HP heat exchanger on the other.