"Stress analysis" can mean anything from a quick check of one line to the complete mechanical verification of a unit. When scope is vague, quotes are not comparable and surprises appear at the first client comment. This is the scope used by the studio for a standard package, and the list of inputs that make a quote reliable.
1. Input review
Before any model is built, the inputs are checked for consistency: design basis and project specification, line list with design and operating conditions, P&IDs, layouts and isometrics (or the 3D model export), piping classes, equipment drawings with allowable nozzle loads, and the support standard. Gaps are listed in an assumptions register that travels with the calculation — the single most useful document when the client asks "why".
2. Model and load cases
The model is built, or an existing one is checked independently. Load cases follow the code and the specification: sustained (weight and pressure), operating at each temperature set, expansion ranges, occasional loads such as wind, earthquake, PSV thrust or slug, hydrotest, and project-specific conditions like settlement or upset temperatures. The free load combination generator shows a typical CAESAR II set.
3. Code checks and equipment
Code compliance is only the start. The package also verifies displacements against clearances, restraint loads, spring hanger travel and load variation, and equipment nozzle loads against API, NEMA or vendor allowables — the item that most often drives re-routing.
4. Recommendations
Where a system does not comply, the deliverable is not just "fails": it is a practical modification — a loop, a guide moved, a spring support, a different anchor — agreed with the layout team so it can be built.
5. Deliverables
- Native model and input echo.
- Stress report with assumptions and compliance summary.
- Support load and displacement tables, spring hanger data.
- Nozzle load assessment.
- Marked-up isometrics.
Scope boundary. Drafting of isometrics and fabrication drawings is a different service; if needed, it should be stated in the request.
What to send to get an accurate quote
- Number of critical lines or systems (or the line list) and the applicable code.
- A sample of isometrics, or the 3D model / existing stress model.
- Equipment involved (pumps, compressors, turbines, air coolers) and their allowables.
- Specification, required deliverables and schedule, including client comment cycles.
With these, a fixed-price proposal can be issued with clear assumptions — and compared fairly with others.