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Root Cause Failure Analysis
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Equipment failures (eg: boiler tube failures) often provide a critical test of the water treatment suppliers ability to respond to a customer problem.
FAILURE ANALYSIS INVESTIGATIONS ANSWER TWO QUESTIONS.
BOILERS
COOLING SYSTEMS
The two questions, which generally need to be addressed are: Why did the failure occur? And what can be done to prevent a recurrence? A root cause failure analysis investigation can provide the answers to both questions. The following discussion reviews one approach, which can be utilized to conduct a successful failure analysis investigation. The analysis of a failure of a component in a piece of heat transfer equipment (for example, a heat exchanger tube failure or boiler tube failure) is quite often a complex exercise involving the evaluation of many different factors. For example, boiler tube failures can result from thermal effects such as rapid overheating, long term overheating, thermal stress, waterside chemical effects such as stress cracking, caustic attack, phosphate corrosion, acid corrosion, oxygen corrosion, galvanic corrosion, under deposit corrosion, design effects such as crevice corrosion or process side/fireside effects such as high temperature ash corrosion or erosion or water side erosion corrosion mechanisms. The identification of the cause of the failure generally requires more than an examination of the failed metal specimen, although such examination is an important component of the elucidation of the mechanism. In practice three areas should be researched in detail to obtain a successful conclusion.
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