Design Basis Screening

Use this skill to assemble and sanity-check a screening design basis: it compares operating capacities and conditions against the proposed design capacities and conditions, computes indicative flow, pressure, and temperature margins, and flags margins below transparent public thresholds. It also echoes the design standards basis. It is intentionally simple and should guide users toward validated mechanical design, the applicable standards (ASME, API, DNV, NORSOK), and qualified engineering review.

When to Use

• When an early concept needs a quick design-margin sanity check.
• When an agent needs an upstream "design basis" feed for a facilities or cost-estimate screening chain.
• When documenting the capacities and conditions a downstream model should use.

Inputs

• operating_flow / design_flow: operating and design flow rate (same unit).
• operating_pressure_bara / design_pressure_bara: operating and design pressure.
• operating_temperature_c / design_temperature_c: operating and design temperature.
• standards: optional list of design standards labels.

Outputs

• flow_margin, pressure_margin: design/operating ratios.
• temperature_margin_c: design minus operating temperature.
• flow_flag, pressure_flag, temperature_flag: ok or low.
• standards: normalized standards basis.
• design_warning: ok or watch.
• flags: human-readable warnings.
• neqsim_available: whether the optional NeqSim package is importable.
• assumptions: public assumptions and required follow-up.

Engineering Method

The skill computes simple margins: flow and pressure as design/operating ratios, temperature as a design-minus-operating difference. Each margin is compared against an indicative public threshold (default 1.10 for flow and pressure ratios, 10 C for temperature). A low flag is raised when a margin is below its threshold, and a missing standards basis is flagged. The verdict is watch when any flag is raised, otherwise ok.

This skill performs no code-rating, wall-thickness, or mechanical-design check. It is a transparent placeholder that must be replaced by validated mechanical design for any quantitative use.

Python Usage Pattern

from design_basis_screening import DesignBasisModel

model = DesignBasisModel()
result = model.evaluate(
    operating_flow=100.0,
    design_flow=120.0,
    operating_pressure_bara=60.0,
    design_pressure_bara=70.0,
    operating_temperature_c=40.0,
    design_temperature_c=60.0,
    standards=("ASME VIII Div.1", "NORSOK P-001"),
)

print(result.flow_margin, result.pressure_margin, result.temperature_margin_c)
print(result.design_warning)
for flag in result.flags:
    print(flag)

Validated NeqSim Path

This screening is a placeholder. For a real design basis use:

• NeqSim mechanical-design classes (neqsim.process.mechanicaldesign) for vessel, pipe, compressor, and heat-exchanger design with code factors.
• The applicable standards databases (ASME, API, DNV, NORSOK) for ratings.
• The community pressure-drop-screening, line-velocity-check, and pipe-wall-thickness-screening skills for related hydraulic and mechanical screening.

Escalation

Escalate any watch verdict, and any quantitative use, to validated NeqSim mechanical design and qualified engineering review against the applicable codes.

Validation Checklist

• Inputs are validated and within stated ranges.
• Examples use public data only.
• Screening assumptions are stated explicitly.
• Limitations are respected.
• Quantitative use is escalated to validated NeqSim models.

Common Mistakes

Limitations

• Educational screening only; not a validated design method.
• No confidential data or proprietary methods are included.
• Escalate any quantitative or design use to validated NeqSim workflows.

References

• NeqSim repository: https://github.com/equinor/neqsim
• NeqSim Skills Guide: https://github.com/equinor/neqsim/blob/master/docs/integration/skills_guide.md