A volume bearing the title Design of Piping Systems, devoted solely to the study of expansion stresses and reactions in piping systems, was privately published by The M. W. Kellogg Company early in 1941. It made available for the first time an adequately organized, comprehensive analytical method for evaluating the stresses, reactions, and deflections in an irregular piping system in space, unlimited as to the character, location, or number of concentrated loadings or restraints. It was the culmination of an intensive, widespread effort to meet the recognized need for refined analysis capable of general application to the increasing number of critical piping services required by technological progress, and to the increasingly severe problems which they posed. The timely availability of this reliable and versatile approach, now widely known as the Kellogg General Analytical Method, made it possible to provide satisfactory design for the avalanche of critical and pioneering piping requirements associated with World War II plant design, and proved to be a major step in accelerating acquaintance with accurate thermal expansion analysis and appreciation of its potentialities for more extensive application.
Since the war, technological progress and the trend to larger scale, more complex units has continued unabated, while the attendant increased pressures, temperatures, and structural complexities have resulted in larger pipe sizes, heavier wall thicknesses, and a marked increase in alloy construction. Concurrently, the wartime-fostered universal acceptance of adequate piping flexibility analysis for critical service has paved the way for more searching examination of the over-all economics of erected piping by relating potential fabrication, materials, and operating savings to increased engineering costs. Earlier concepts, which regarded piping as trivial and expendable, are fast disappearing in view of the rising costs of field corrections and loss of plant operation — and also with the recognition that piping represents an increasing percentage of initial plant expenditure.
The importance of sound piping design is now well recognized not only by designers and users, but also by authorities concerned with public safety. The Code for Pressure Piping Committee (ASA B31.1) has increased its membership and activity over the past several years and a Conference Committee has been organized, composed of the chief enforcement authorities of each State or Province that has adopted a portion or all of the Code. Significant improvements in the rules have already resulted in the revised minimum (and now mandatory) requirements for piping flexibility. With this trend, the ASA Code is now rapidly assuming the status of a mandatory Safety Code, whereas previously it had served designers and users primarily as a recommended design practice guide.
The critical shortage of engineering personnel during World War II prevented the completion of sections on other aspects of piping design that had been planned for inclusion in the original edition of Design of Piping Systems. As the shortage persisted, considerable time elapsed before resumption of work could be considered. Meanwhile, many requests for extension and suggestions for improvement were