ABSTRACT
In 1998, one year before occurrence of the accident, it was reported that the refinery’s desalting unit ran 40% above its original design capacity. This was mainly caused by a change from lighter to heavier crude oils which led to a decrease in the ability to separate salts, water, suspended solids and other unwanted materials. Several reports and recommendations on improvements of the desalting unit were made during 1998. Its performance and efficiency were described as “hopeful to nonexistent” and “never been more difficult” (Board, 2001). Although the management knew about the problems, and what could be done to improve the situation, they did not follow the procedures given in order to avoid accidents associated with unwanted consequences. This in the end led to an increase in corrosion in the system. On February 10th, 1999 a leak at the top of the naphtha piping connected to the tower was discovered (valve A in Figure 1). Several attempts were made to tighten the leak, but were not successful. A closer inspection of the leaking pipe revealed that it was severely corroded and a decision was made to replace a large section of the naphtha line.
