Conical shells feature commonly in pressure vessels and piping, for ex
ample as reducers and end closures. When a conical shell is joined to
a cylindrical shell, a slope discontinuity is introduced in the shell
meridian, leading to local high bending and circumferential membrane s
tresses when the shell is pressurized. The strength of cone-cylinder i
ntersections is therefore a major concern for the designer. This paper
presents an investigation into the collapse behavior and strength of
cone large end-to-cylinder intersections with locally increased wall t
hickness (i.e., sleeving or sleeve reinforcement) under internal press
ure. The study is aimed at developing a simple method for the estimati
on of the axisymmetric failure strength. Simple equations for the plas
tic limit loads are first developed based on small deflection elastic-
plastic finite-element calculations. An approximate procedure for taki
ng into account the beneficial effect of geometrical change is then su
ggested and briefly discussed. The strength equations established here
are directly applicable in practical design and are suitable for futu
re inclusion into pressure vessel codes.