Piping systems, design flexibility stress

Thermal expansion and the resultant pipe stresses must be considered in any piping system design. For example, if the temperature changes from 50 to 600°F, the increase in length would be 4.9 in. per 100 ft for steel pipe and 7.3 in. per 100 ft for brass pipe. This amount of thermal expansion could easily cause a pipe or wall to buckle if the pipe were fastened firmly at each end with no allowances for expansion. The necessary flexibility for the piping system can be provided by the use of expansion loops, changes in direction, bellows joints, slip joints, and other devices. 

In addition to the design requirements for pressure, weight, and other loadings, hydrogen piping systems subject to thermal expansion and contraction or to similar movements imposed by other sources shall be designed in accordance with the requirements for the evaluation and analysis of flexibility and stresses specified herein. 

A complete presentation of stress and flexibility analysis and design in piping systems is beyond the scope of this book. This section will serve as an introduction to the subject, and references for more detailed study will be included. 

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