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Deaerator Troubleshooting and Preventative Maintenance

Mitigate risks to your critical equipment


Essential in minimizing damage to equipment and operations, deaerators play the critical role of removing oxygen and other dissolved gases from steam generator feedwater. When left unchecked, gases such as oxygen and carbon dioxide can cause corrosion and resultant cracking, which are dangers to a boiler's performance.

Cracks and other problems in deaerator systems can be caused by a variety of factors and usually develop along a boiler's welded seams. Several of these factors include

  • Excessive pressure fluctuation
  • High oxygen or CO2 levels
  • Low outlet temperatures
  • Unexpected storage tank level excursions
  • Water out of the vent
  • Presence of iron oxide in the deaerator

Once cracks develop, they spread quickly, leading to failure of the deaerator, and a potentially negative impact upon site operations.

TÜV SÜD Global Risk Consultant’s (GRC's) recent Deaerator Study revealed that potential business interruption associated with cracked deaerators totaled $27.7 million for the inspected facilities where cracks were found, which equals to 1.319 million dollars per site. Approximately 4,000 Euro would be needed per site to adequately inspect the deaerators and take corrective action.


Regular inspections and preventative maintenance are critical to the continued operability of deaerators and production. The National Association of Corrosion Engineers (NACE)'s 1996 study reported that general cracking was found on 41% of inspected deaerators. NACE recommends frequent deaerator inspections, the first occurring 1-2 years following a deaerator's installation. Following that, inspections should occur:

  • Every year or less if weld cracks were repaired.
  • One to two years if non-weld defects were repaired.
  • Three to five years if no cracks were found, and no repairs were needed.


TÜV SÜD GRC’s own Deaerator Weld Inspection Study examined 99 facilities within the cocoa, milling, oilseed, salt, starch, and protein industries. Using predictive analytics, the study is one example of TÜV SÜD GRC's preventative -rather than reactive- approach to risk management.

The purpose of the study was to both expand upon the NACE study, and determine if the NACE study’s findings are still relevant to the global market.

TÜV SÜD GRC's study concluded that minor and major forms of cracking had been found on 30% of deaerators. Not only that, cracked deaerators are still being found, worldwide, across all industries (as seen on the left). Because of this, it can be determined that the NACE study is indeed still valid, although there is still room for future expansion of this TÜV SÜD GRC study.


Through the use of data analysis, TÜV SÜD GRC's deaerator study exemplifies how predictive analytics can be key to preventing failure in regular business operations.

Our services enable your organization to achieve its specific loss prevention goals and objectives. We support you in developing action plans to control losses and avoid breakdowns, while enabling you to identify, track and trend specific concerns. In addition to concentrating your resources on critical needs, we identify ways to improve operational efficiencies.

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