Jord was engaged to undertake a comprehensive failure analysis to determine the cause of failure. Initial analysis of the process fluid indicated that chloride levels were well within the limits for the material selected.

The damaged tubes were not immediately available and analysis was limited to review of the design, materials and manufacturing processes, analysis of vibration, differential expansion and manufacturing stresses utilizing FEA, analysis of chemical composition of external environment and review of air cooler operation

Once tube samples became available, further analysis involved metallographic and chemical examination, SEM/Fractography & EDX analysis, mechanical & corrosion testing and comprehensive metallurgical analysis. Jord’s comprehensive study determined that though the chloride level of the process fluid was below the limit for the selected material, the operating conditions caused localized condensation that increased chloride concentrations to levels well above those of the process fluid and far exceeding that acceptable for utilization of SS316L. The result was stress corrosion cracking of tubes & eventually header bottom plate.

As a result of the analysis, the client engaged Jord to upgrade the bundles from 316L to Incoloy 825. Not just at this facility but also subsequently at other regional sites where similar conditions were identified. The client also revised its specifications to avoid a reoccurrence on future project, thereby greatly improving the reliability and asset integrity.