Describe the term "cyclic loading" as it relates to pressure piping.

Cyclic loading refers to the phenomenon where a material, such as the materials used in pressure piping systems, experiences repeated cycles of stress or strain. This means that the stress applied to the piping isn't constant but varies over time, which can lead to fatigue in the material. The repeated application of pressure and the resultant loading during operation simulate a back-and-forth pattern of stress that can eventually weaken the piping material. Over time, this can result in the development of micro-cracks and may lead to catastrophic failure if the fatigue is not mitigated or addressed.

In pressure piping systems, cyclic loading is particularly important to understand because many operational scenarios—such as the intermittent operation of pumps or valves—can cause fluctuating pressures within the pipes. Recognizing this concept helps ensure that appropriate materials and designs are chosen to withstand these stresses over their expected life span.