Piping systems — pipes, fittings, valves and other items — not only must convey fluids (liquids and gases) from one location to another but also must cope with mechanical stresses. So, it is essential to check a system’s mechanical behavior under regular loads (internal pressure, thermal stresses, dynamic forces, etc.) as well as under occasional and intermittent loading cases such as special vibration or pulsation. This evaluation usually relies upon commonly used rules and guidelines or involves review by an expert; sometimes specialized software performs the piping stress analysis. Typically, pipe stress engineers verify that the routing, nozzle loads, hangers and supports are appropriate and adequate to ensure allowable pipe stress isn’t exceeded during situations such as sustained operations, pressure testing, etc.
Localized stresses in piping systems and their supports demand attention because they can lead to different types of failures. Such high stresses in steel structures and piping components can arise, for example, from sharp corners in the design or inclusions in a material.
Another area of concern is operating temperature range; piping and its supports for high or very low operating temperatures require special designs. High temperature poses issues of strength of materials, thermal expansion and thermal stress. Low temperature brings its own set of rules and guides; for instance, most ordinary steels become more brittle as the temperature decreases from normal operating conditions. So, it’s necessary to know the temperature distribution for these applications and select materials accordingly.
To learn more about piping, read “Mind Piping System Mechanics” from Chemical Processing.
