Determination of Safe Operating Conditions for Non-gasketed Flange Joint under Combined Internal Pressure and Temperature

Abstract

Performance of a flange joint is characterised mainly due to its ‘strength’ and ‘sealing capability’. A number of analytical and experimental studies have been conducted to study these characteristics only under internal pressure loading. However, with the advent of new technological trends for high temperature and pressure applications, an increased demand for analysis is recognised. The effect of steady state thermal loading is a well recognised problem and makes the problem more complex under combined application of internal pressure and temperature. The present design codes do not address the effects of temperature on the structural integrity and sealing ability. To investigate, joint strength and sealing capability under combined internal pressure and different steady state thermal loading, a 3D non-linear finite element analysis of non-gasketed flange joint is carried out and its behaviour is discussed. To determine the safe operating conditions or actual joint load capacity, the joint is further analyzed for different internal pressures and temperatures. In addition, effect of coefficient of thermal expansion of different flange joint component material is discussed and importance is highlighted.