Tank, Vessel & Pressure Equipment Fabrication worked example

Weld Length Estimate with weld defect severity rating of 3 score: a worked example

This worked example runs the weld length estimate numbers for a tougher week than the baseline: weld defect severity rating of 3 score instead of the typical 6 score. This Weld Length Estimate tool is a weighted weld-risk index that blends how severe a weld defect would be, how likely it is to occur, and how hard it is to detect into one prioritization number.

The inputs for this scenario

  • Weld defect severity rating: 3 score (the input this scenario stresses; the baseline uses 6)
  • Defect occurrence likelihood: 4 score (held at the documented default)
  • Inspection detection difficulty: 3 score (held at the documented default)

Working through the calculation

  • The calculation starts from the formula this tool documents: Weld Length Estimate risk score = severity × 0.40 + occurrence × 0.35 + detection × 0.25.
  • Risk score works out to 3.35 ft at these inputs, and this is the headline figure for the scenario.
  • Severity works out to 3 score at these inputs.
  • Occurrence works out to 4 score at these inputs.
  • Detection works out to 3 score at these inputs.

How this compares with the baseline

  • Against the tool's baseline example, where weld defect severity rating sits at 6 score and the headline result is 4.55 ft, this scenario comes in 26.37% below the baseline at 3.35 ft.
  • Use it while planning the NDE and inspection plan for a vessel, to rank weld joints by risk before committing radiography budget. A result at this level usually justifies acting on the stressed input before touching anything else, because every other figure in the table is downstream of it.

Results at a glance

  • Risk score: 3.35 ft (headline result)
  • Severity: 3 score
  • Occurrence: 4 score
  • Detection: 3 score

Run it with your numbers

  • To rerun this with your own numbers, open the live Weld Length Estimate calculator, set weld defect severity rating to your actual value, and adjust the remaining inputs to match your operation.

Last reviewed 2026-05-12.