Piping Stress Analysis

TNI performs piping stress analysis in CAESAR II to ASME B31.3 (or the code specified by the project), keeping systems safe under thermal expansion, protecting pumps, vessels and equipment from overload, and optimising the number and type of supports.

Scope of analysis

Item	Content
Critical line list	Lines selected by project criteria: temperature, size, pressure, rotating equipment connections, relief (PSV) lines
Sustained loads	Weight of pipe, fluid and insulation, and pressure
Thermal expansion	Displacement stress range checked against allowable limits
Occasional loads	Wind, seismic and relief valve reaction loads when required
Support loads	Forces and moments at supports for structural design
Nozzle loads	Compared with manufacturer or code limits (e.g. API 610 for centrifugal pumps); vessel nozzle checks when needed
Vibration & fatigue	Assessment for lines with thermal cycling or vibration

Deliverables

• Stress analysis report: input data, load cases, results and conclusions.
• Support load list for the structural discipline.
• Stress mark-up isometrics: guides, line stops, spring supports.
• Routing changes: expansion loops and flexible joints where justified.

Practical experience

• Pump piping is a common cause of vibration and seal failure; supporting close to the pump and checking nozzle loads during routing avoids rework.
• Add flexibility by changing pipe routing before using expansion joints, which need maintenance and introduce pressure thrust.
• Spring supports must be locked for pressure testing and released before operation – note this clearly on the drawings.

Related services: 3D/2D plant design · Tank & pressure vessel design