Structural integrity and sealing behaviour of bolted flange joint: A state of art review.

Bolted flange joints are widely used in pressure vessels and piping. With the increase in installation of nuclear power plants, chemical industries and oil and gas transportation facilities, design of highly reliable leak proof joints has become an important concern. Bolted flange joint is subjected to many uncertainties such as material and geometric nonlinearities, load distribution and its relaxation. Hence, there is a need to understand the behaviour of bolted flange joint under different conditions, with varying bolt load, internal fluid pressure, temperature and occasional loads. In the present study, the influence these factors on the leakage of bolted flange joints are reviewed in detail. The significance of variation in axial joint stiffness due to bolt load relaxation at elevated temperature is discussed. Attention is also given to sealing performance and prediction of leakage rate under different loading conditions. The load bearing capacity and failure criteria of flange joint, along with the effect of loading history are also discussed. Then, the focus is turned towards the numerical formulations of flange joint under dynamic loads, in addition to experimental techniques to extract its response. Further, the current challenges in this area along with future scope for improvement to achieve leak-proof and structurally sound flange joint are also discussed in this review article. • Load relaxation in bolted flange joint due to creep and thermal loads. • Effective material characterization techniques of nonlinear gasket material. • Behaviour of flange joint subjected to thermal and external loads is discussed. • Sealing performance and prediction of leakage rate under different loading conditions are highlighted. • Recommendation to overcome joint relaxation is also discussed. [ABSTRACT FROM AUTHOR]