168. Designing Pressure Vessels for Optimum Weight

Paper

Abstract

The weight of pressure vessels constitutes a sizeable part of the total weight empty of modern, high performance aircraft and missiles. If performance is to reach its peak efficiency, then every effort must be made to design pressure vessels with optimum weight. Regardless of whether the pressure vessel is designed as an integral or non-integral tank, the same basic design considerations apply. They are:
1. Examine the design conditions and determine that the tank components meet those conditions.
2. Use the optimum shape for the particular application. Wherever possible, use spherical shapes.
3. Remember that for geometrically similar shapes, the weight of the container shell is independent of the number of vessels used to contain a given volume of fluid at cu1Ibtutt pressure and temperature.
4. Remove excess material either by machining or chemical milling.
5. Make a careful selection of the material for the particular application, keeping in mind that steel can often save weight in pressure vessels.
6. Take advantage of low temperature environments to reduce pressure vessel volumes and increase allowable tensile strengths.
7. Make use of non-standard gages and oversized sheets where their use results in a weight reduction.
8. Where possible, use tapered skins to reduce the weight of pressure vessels.
9. Vary the product of pressure and volume of a gas without affecting weight in order to fit the pressure vessel into available space.
The success of tomorrow’s aircraft and missiles can be measured only in terms of performance. A sizeable contribution toward that success can be made by designing pressure vessels for optimum weight. The fruits of our efforts will be measured by improved range, velocity, altitude, or payload.