Calculator Inputs
Enter qualified WPS values and compare them with the proposed field setup.
Example Data Table
| Scenario | Qualified Process | Qualified Thickness Range | Proposed Thickness | Qualified Heat Input | Proposed Heat Input | Indicative Outcome |
|---|---|---|---|---|---|---|
| Structural beam groove weld | SMAW / E7018 / 3G | 6.00 to 20.00 mm | 12.00 mm | 1.456 kJ/mm | 1.677 kJ/mm | Review needed if tolerance is 15% |
| Pipe support fillet weld | FCAW / E71T-1 / 2F | 8.00 to 18.00 mm | 10.00 mm | 1.836 kJ/mm | 1.790 kJ/mm | Normally within screen window |
Formula Used
Heat Input = (Voltage × Amperage × 60 × Efficiency) ÷ (1000 × Travel Speed)
Heat Input Ratio = Proposed Heat Input ÷ Qualified Heat Input
Qualified Heat Window = Qualified Heat Input ± Tolerance Percentage
Change Severity Index = Sum of weighted essential variable triggers
This calculator is a screening aid. Final acceptance should always follow the governing code, approved WPS, PQR, and project welding requirements.
How to Use This Calculator
- Enter the qualified WPS or PQR basis values first.
- Enter the proposed field welding values next.
- Set the acceptable heat input tolerance percentage.
- Press the calculate button to compare both sets.
- Review critical changes before releasing work to site.
- Export the result as CSV or PDF for records.
FAQs
1. What does this calculator check?
It screens common WPS essential variables against a qualified baseline. It compares process, material group, thickness, filler, diameter, position, preheat, PWHT, gas, polarity, and heat input.
2. Does a flagged result always mean requalification?
No. It signals that engineering review is needed. Final disposition depends on the governing code, the approved procedure, client requirements, and the supporting qualification record.
3. Why is heat input included?
Heat input affects fusion, cooling rate, hardness, distortion, and mechanical performance. Large deviations can indicate a meaningful procedure change, especially on controlled structural welding work.
4. Can I use this for every welding code?
Use it as a site screening tool only. Different codes define essential variables differently. Always verify the exact acceptance logic against your project code and approved documentation.
5. What should I enter for PWHT when none is used?
Enter 0 for both qualified and proposed PWHT. The calculator interprets zero as no post weld heat treatment requirement.
6. How should shielding gas be entered?
Type the gas mix clearly, such as CO2, Ar/CO2 80/20, or None. For gas-dependent processes, any meaningful change is flagged for review.
7. Why does position matter?
Weld position changes deposition behavior, puddle control, and operator difficulty. A position change may affect qualification coverage and should be checked carefully.
8. What records should be saved with the output?
Save the exported screen with the WPS number, revision, weld map reference, project code, inspector notes, and any engineering review decision.