Purpose of stress analysis
From a mechanical standpoint, stress analysis ensures that a piping system, whether connected to equipment or not, remains safe under all possible conditions:
- Under normal operating conditions
- Under abnormal (upset) conditions
To ensure piping systems operate safely, stress analysis considers several key factors:
- Comply with piping code constraints under which the system is designed, manufactured and tested.
- Adhere to the maximum forces allowable on connected equipment.
- Comply with stress limits for structural piping supports.
- Ensure proper support for all load conditions to ensure piping remains in place.
- Limit vertical deflection between supports, especially for sloped pipes used for drainage.
- Prevent interference between pipes under all operating scenarios.
CAESAR II software
BBA uses CAESAR II software for stress analysis. This tool simulates how a piping system behaves under various conditions, including:
- The weight of piping system components and external elements, such as ice
- Thermal expansion or contraction caused by fluid temperature differences relative to the installation temperature
- Displacements imposed by external elements, such as structural displacements
- Forces from wind and seismic activity
- Loads induced by activating safety devices in the system, such as relief valves and rupture disks
The software calculates stresses based on the equations of the relevant piping code for different loading conditions. It then compares these calculated stresses with the allowable limits specified in the code.
Moreover, built-in subroutines help users verify that forces and moments at the connection points of rotating and non-rotating equipment remain within acceptable limits. These limits vary depending on the equipment type and applicable industry standards.