Journal of Failure Analysis and Prevention

, Volume 15, Issue 6, pp 782–788 | Cite as

Failure Analysis of Severely Corroded Steam Coil in Water Seal Vessel

Case History---Peer-Reviewed

Abstract

Repeated failures have been experienced in steam coil installed in a water seal vessel. The steam coil was found severely corroded after 9 months of operation especially at the steam inlet. Several samples were collected from different locations for examination and failure investigation. The investigation included visual examination, XRF\CS, and SEM\EDS analysis. It is concluded that the failure mechanism was acid attack caused mainly by sulfuric acid found in the water inside the vessel. It is recommended to eliminate the source of sulfuric acid by controlling the inlet of process gas into the vessel. In addition, measurement of pH and conductivity of the water in the vessel must be conducted regularly. Moreover, under standard operating parameters, material ASTM A-106 Gr. B carbon steel performs well in this environment and material upgrade is not required. However, if it is not feasible to prevent the ingress of sulfuric acid then upgrading the material is necessary.

Keywords

Corrosion Steam Sulfuric acid Carbon steel Steam coil Failure analysis 

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Copyright information

© ASM International 2015

Authors and Affiliations

  1. 1.Manufacturing Center of ExcellenceSABICJubailSaudi Arabia
  2. 2.Home of InnovationSABICJubailSaudi Arabia

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