Host: The Japan Society of Mechanical Engineers
Name : [in Japanese]
Date : September 09, 2018 - September 12, 2018
T-junctions are widely used for fluid mixing in process plants. Temperature fluctuations generated by the mixing of hot and cold fluids at a T-junction can cause high cycle thermal fatigue failure. This kind of phenomenon is generally called thermal striping. JGC Corporation has tackled thermal striping failure incidents since early 2000s. This paper presents JGC corporation's thermal striping failure experiences and two failure examples which occurred at a chemical plant and a refinery plant. For both cases, fatigue failures generated at inner surface were found. Root cause analyses were conducted using CFD analysis and JSME S-017 2003, and it was concluded that both fatigue failures occurred due to thermal striping. For such high cycle fatigue failures, installation of thermal sleeve is a typical countermeasure for a new plant. For existing plants without thermal sleeve, a periodic inspection is a typical and effective prevention measure. However, cause of failure may be a combined effect of thermal striping and other phenomena such as stress corrosion cracking. Thus, investigation from a wide-ranging point of view is necessary.
