Explosion in a Fertilizers Plant (223)

The vent occurred in the ammonia production unit. A minor leak had been detected in a flange on the piping of the ammonia synthesis loop (operating at 250 bar). The company called a specialized external contractor to perform an on-stream repair of the valve. This solution was chosen because of for the limited extents of the leakage and the economic costs and efforts associated to a shut-down of a very complex system.