What Reviewers look for in Calculations with PV Elite

Three things that determine whether a PV-Elite analysis is accepted

When PV-Elite models are reviewed internally, most discussions do not start with formulas or code clauses. They start with how the model was set up.

Pressure vessel calculations produced in PV-Elite often pass all code checks and still attract review comments. In most cases, this is not because the analysis is incorrect. It is because the basis of the model is not immediately clear to the reviewer. In practice, reviews tend to converge quickly when three things are clear. When they are not, reviews slow down regardless of how low the stress utilisation is.

This article focuses on these three points.

1. The design basis must be obvious before anything else is reviewed

Before stresses, ratios, or detailed reports are considered, reviewers typically confirm that the design basis is unambiguous.

This usually includes:

• the applicable design code (e.g. ASME VIII Division 1, EN 13445, PD 5500),
• design pressure and temperature,
• corrosion allowance,
• reported MAWP for the vessel and its components.

PV-Elite presents this information early in the output, but reviewers will still check whether:

• MAWP is greater than or equal to design pressure plus static head,
• the governing temperature aligns with the specification,
• corrosion allowance has been applied consistently.

If any of this is unclear or scattered across reports, the review often pauses here. Even a technically correct model becomes difficult to assess without a firm design basis. Conversely, a clear design basis allows everything else in the PV-Elite calculation to be interpreted correctly.

The MAWP is shown in the Vessel Design Summary.

2. Thickness philosophy determines whether results are trusted

Once the design basis is accepted, the next question concerns the thickness intent.

PV-Elite reports:

• required thickness,
• actual thickness,
• corroded and uncorroded conditions,
• hot and cold MAWP values.

What reviewers want to understand is not just whether a thickness passes, but:

• whether it was selected deliberately,
• whether it was adjusted automatically by the software,
• whether it represents sizing or verification.

If automatic thickness selection was enabled, PV-Elite may increase wall thicknesses to satisfy pressure criteria. This is useful during early exploration, but it changes how results should be interpreted later.

Typical review questions include:

“Is this thickness a design choice, or something PV-Elite adjusted?”

“Does this thickness match the drawing, or is this a sizing model?”

If the thickness philosophy is unclear, reviewers may request clarification or re-runs even when utilisation is low. Clear thickness philosophy avoids this entirely.

3. Warnings are interpreted, not ignored

PV-Elite distinguishes between failures and warnings, and a model can pass with warnings present. During review, those warnings are almost always read.

Common warnings include:

• minimum design metal temperature (MDMT) messages,
• unit conversion notes,
• code-specific advisory statements.

Reviewers are usually not expecting all warnings to be eliminated. They are expecting that:

• warnings have been noticed,
• their relevance is understood,
• and their impact has been consciously accepted or dismissed.

A common review response is:

“This looks acceptable, but why does this warning appear?”

Acknowledging warnings and understanding whether they affect the design builds confidence. Ignoring them often does the opposite.

Warnings can be found in the "Warnings and Errors" report.