PVP2014-28270 A Survey Method to Optimize Bolted Flanged Joint Assembly Torques for ASME B16.5 Flanges

The three critical components within a bolted, flanged connection are the flanges, gasket, and bolts. Until recently, simplified flange assembly target torque values for ASME B16.5 flanges were routinely determined by considering just one or two of these primary components. One approach considers only the gasket. Gasket-based target torque values are selected to optimize the gasket’s sealing performance by ensuring compression between minimum and maximum seating stress ranges, or based upon achieving specific levels of gasket Tightness (Tp). Another approach, fastener-based torque values, simply targets a specific bolt preload during assembly, typically some percentage of bolt material yield stress. A third approach optimizes gasket seating stress or tightness within the specific preload stress range o