Experimental Investigation into the Stress Distribution in a Band-Reinforced Pressure Vessel

A model of a band-reinforced, cylindrical, reactor pressure vessel has been manufactured and tested. The vessel dimensions were 5 ft inside diameter by 9 ft overall length, with hemispherical ends, nominal plate thickness being 1 in. throughout. Hoop reinforcement on the barrel consisted of 3-in. wide circumferential bands, each band being built up of 13 layers of -in. strip, giving a total band thickness of 1 in. Full details of design, construction, and method of manufacture are given.

A complete experimental investigation into the stress distribution in the vessel has been carried out, using electrical resistance strain gauges, both at its design pressure of 1000 lb/in² and also at twice this pressure. The stress distribution on the inner surface of the barrel, on the outer surface of the bands, and local to the tangent line has been measured. These results are compared with theoretical calculations.

Finally, the vessel was pressurized to destruction.

The results show that, as would be expected, the band reinforcement was not fully effective. However, the general stress level was maintained within acceptable limits, the theoretical stresses being exceeded by about 20 per cent. The bursting pressure of 3940 lb/in² confirms the safety of the design, that is, a design factor of safety of 3·94.

It is considered that the results of the investigation fully demonstrate the safety and merits of the design.