Journal of Failure Analysis and Prevention

, Volume 7, Issue 1, pp 18–22 | Cite as

Corrosion Failure of Bottom Plates of an Aboveground Storage Tank

Case History
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Abstract

This paper describes the investigation of a corrosion failure of bottom plates on an aboveground tank used for the storage of potable water. The tank was internally inspected for the first time after six years of service. Paint blisters and rust spots were observed on the bottom plates and first to third course shell plates. Sand blasting and repainting of the bottom plates and first course shell plates was to be used as a remedial measure. However, during the sand blasting, holes and deep pitting were observed on the bottom plates. On-site visual inspection, magnetic flux leakage (MFL) inspection, ultrasonic testing (UT), and evaluation of the external cathodic protection (CP) system were used in the failure analysis. The corrosion products were analyzed using energy-dispersive X-ray analysis (EDAX). The failure is attributed to the ingress of water and its impoundment under the tank bottom along the periphery inside the ring wall and failure of water side epoxy coating. Various measures to prevent such failures in the future are recommended.

Keywords

Coating thickness Corrosion failure analysis EDS Nondestructive examination 

References

  1. 1.
    C.G. Munger: “Coatings and Cathodic Protection,” Corrosion Prevention by Protective Coatings, National Association of Corrosion Engineers, 1984, p. 235.Google Scholar
  2. 2.
    C.G. Munger: “Coatings and Cathodic Protection—cathodic disbonding tests,” Corrosion Prevention by Protective Coatings, National Association of Corrosion Engineers, 1984, p. 332.Google Scholar
  3. 3.
    C.G. Munger: “Coatings and Cathodic Protection—cathodic disbonding tests,” Corrosion Prevention by Protective Coatings, National Association of Corrosion Engineers, 1984 p. 335.Google Scholar

Copyright information

© ASM International 2007

Authors and Affiliations

  • M. Mobin
    • 1
  • A. U. Malik
    • 1
  • S. Al-Fozan
    • 1
  • F. Al-Muaili
    • 1
  1. 1.Research & Development CenterSaline Water Conversion Corporation (SWCC)Al-JubailSaudi Arabia

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