Determination of load capacity of a nongasketed flange joint under combined internal pressure, axial and bending loading for safe strength and sealing

Performance of a bolted flange joint is characterized 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. A very limited work is found in literature under combined internal
pressure and bending loading. Due to the ignorance of external loads i.e. bending and axial in addition to the internal pressure loading, an optimized performance of the bolted flange joint can not be achieved. The present
design codes do not address the effects of combined loading on the structural integrity and sealing ability. To investigate joint strength and sealing capability under combined loading, an extensive comparative experimental and numerical study of a non-gasketed flange joint with two different taper angles on the flange surface and with different load combinations is carried out and overall joint performance and behavior is discussed. Actual joint load capacity is determined under both the design and proof test pressures with maximum additional external loading (axial and bending) that can be applied for safe joint performance.