Steam Piping for High Pressures and High Temperatures

Consideration of the following matters is made important by recent progress to high operating steam pressures and temperatures: the changing and more favourable distribution of stress in a pipe, the accompanying creep, and their application to the rational and economical design of steam piping; the determination of permissible working stress; differences in American and British procedures and consequent differences in stress magnitudes; the influence of operating fluctuations of pressure and temperature and the choice of a design temperature at rated pressure to provide for them; tentative considerations of behaviour of ferritic and austenitic steels; the action of creep at operating pressure and temperature in reducing and removing the initial thermal expansion loading of a pipe-line, and in imposing it fully when cold.

In these connexions some consideration should be paid to bolted, or otherwise removable, joints at terminal or other special positions; the problem of making a joint between ferritic and austenitic steel piping and components; the factors of materials and corrosion; promised adequacy of existing ferritic steels for present requirements, and application of the principles operative at very high temperatures to piping for less advanced conditions, and economy arising therefrom.