An Alternative Form of Pressure Vessel of Novel Laminar Construction
Although Class 1 welded vessels have been used to an increasing extent for what might be termed moderate-pressure purposes, most of the vessels required for chemical reactions at really high pressures have up to the present been of forged construction—at any rate in this country. There are certain drawbacks and limitations associated with the forging method of construction, and attempts have therefore been made to develop an alternative type of pressure vessel. One such attempt is that of the “multi-layer” vessel developed in the United States by the A. O. Smith Corporation. This consists of a central welded tube on which successive layers of relatively thin plate are wrapped and welded. The present paper describes a vessel of novel laminar design, the main advantages of which are that the vessel can be built up from plate, which is relatively cheap and available from many sources of supply, and the actual construction and assembly does not call for equipment other than that likely to be found in a good engineering construction shop. Furthermore, the present proposed method of construction will allow the manufacture of vessels far larger than can be produced as single forgings, where the limit in regard to ingot size has already been reached. Two of these laminar vessels have been constructed and have given satisfactory service at 350 atmos. pressure for some years. The paper describes the design, construction and testing of these vessels and makes observations on the cost aspect and the future possibilities.