Piping Stress Services
Piping stress services are crucial to ensure the safety and reliability of industrial piping systems. By evaluating the effects of static and dynamic loads on pipe materials, piping stress services help companies identify potential problems before they occur. This can reduce costly downtime, equipment damage and safety hazards.
Pipes must be capable of withstanding static and dynamic loading conditions such as deadweight (self-weight of the pipe, fluid and fittings), internal pressure, vibration, thermal expansion, water hammer, shock and relief valve discharge. To analyze the stresses in a piping system, a piping stress engineer uses specialized software programs such as CAESAR II, AutoPIPE, ANSYS Mechanical APDL, AVEVA E3D or ROHR2. These specialized programs allow a piping stress engineer to model and evaluate complex piping systems with the aid of advanced finite element analysis capabilities.
The piping stress services offered by engineering consulting companies help companies optimize their design, comply with regulations and achieve better efficiency. In addition, these services can also help companies avoid costly repairs and maintenance. However, many plant maintenance, inspection and engineering personnel lack a deep understanding of the underlying engineering behind pipe stress. In many cases, piping stress may only be a minor part of their daily responsibilities.
To address these concerns, PT&P has developed a primer on Pipe Stress to provide a brief overview of the principles of Pipe Stress Analysis for those who want to learn more. Ultimately, the objective is to develop a basic level of knowledge that can be leveraged by those who have the primary responsibility for managing Pipe Stress issues at their plants.
The Pipe Stress Primer introduces the basics of piping stress, including the types of stresses in a piping system and their effects. It also highlights the different factors that can affect piping stress, such as material selection and support spacing. The primer can also be used as a reference for those who are learning to use the industry-standard piping stress program CAESAR II or AutoPIPE.
Static Loads Deadweight, internal and external pressure. Dynamic Loads Vibration, water hammer, shock, pulsation and transient flow. Occasional Loads Wind, seismic disturbances, PSV discharge.
A piping system must be designed to withstand the stresses generated by these sustained loads, without exceeding the maximum allowable stress value for the metal. The resistance of the system balances these forces, ensuring that they remain in equilibrium. Exceeding the allowable stress value results in catastrophic failure of the piping system. A piping stress engineer must therefore use the appropriate sizing method and consider the material’s properties, temperature and loading conditions. The piping stress calculation must take into account axial and bending stresses as well as shear stresses due to the load distribution. In addition, a piping stress engineer must calculate the nozzle loads on piping connected equipment and keep them within their predetermined allowable limits. Finally, the piping stress engineer must select the correct type of pipe support based on the piping stress calculation and check that pipe displacements at maximum and minimum temperatures are within their respective tolerances to prevent clashes with other equipment.
