Tests of some Taper-Hub Flanges with Narrow Gaskets

Abstract

Seventeen 4 in bore models having two pipe thicknesses, various flange thicknesses and hub lengths, made of spheroidal graphite (s.g.) iron, mild steel and bronze, were subjected to series of initial bolt tensions and, at each bolt tension, pressurized in stages to leakage or failure of the metal. Outer surface strains were measured at each stage. Elastic behaviour was also determined from some Araldite models using strain gauges or frozen stress photoelasticity. The elastic flange-hub fillet stresses due to initial tightening are compared with predictions based on Taylor-Forge and DIN methods of calculation. For different positions of gasket reactions, the effect of internal pressure on flange fillet stresses may be predicted from consideration of the external forces. Plastic-elastic behaviour is described; leakage and failure characteristics are presented.