Stress analysis in piping connection thermal sleeves - some design criteria

A statement of the problems that present piping connections subjected to sudden cooling has been made, emphasizing the importance of a suitable choise of the design to reduce thermal stresses. The analysis methodology has also been explained by means of finite element programs. The application to two specific thermal sleeve cases has permitted discussion of the results in the most critical sections and locations. On modifying the dimensions of one of them, the impact on thermal stresses has been verified, proving that it is significant only as far as fatigue is concerned. The stress values obtained are very high, making the simplified elastoplastic procedure necessary. Even after this, the results are very near the admissible limits. This means that in even more critical cases than those considered above, design validation would require a stress analysis based on plastic behavior. (orig.)