Coker Blowdown Pipe Rupture Case Study

Problem

Pipe ruptures occurred at a major refinery Coker blowdown system. The problem was investigated by the internal engineering group and other consultants. KHE was called in because of our capability to analyze the process and mechanical response of the unit using our Integrated Systems Approach. The failure cost over $1MM in expense and posed a safety hazard.

Solution

KHE field services group instrumented the unit. KHE recorded the pressure, temperature, flow, and vibration during the ten plus operating modes. Pipe stress analysis was performed to analyze large-scale piping response. The process was analyzed and determined that thermal shock occurred during one transient event. Using Finite Element Analysis, we modeled the field data in a structural model of the piping section and determined that the thermal shock created sufficient stress to rupture the line. KnightHawk Engineering's field services group verified this occurrence as part of the process cycle.

Result

A process change with rerouting of two process streams solved the problem. The client has experienced no more problems with this unit.