A first-stage impeller in a synthetic gas compressor failed
after 20 years of service. The compressor is a six-stage
centrifugal compressor driven by a steam turbine. This case
history discusses the investigative methods, such as visual and
fractographic examinations, to identify the root cause for the
fracture of the impeller. The leading contributing cause was a
combined action of fatigue and sulfide stress cracking (SSC).
The case history also discusses practical corrective actions to
boost the compressor reliability and sustainability.