Porosity Acceptance Calculator
Evaluate porosity against AWS D1.1 and ASME acceptance criteria.
AWS D1.1 RT Porosity Limits
| Thickness | Max Single Pore | Max Sum (any 6") |
|---|---|---|
| ≤ 12mm | 2.5mm (3/32") | 10mm (3/8") |
| 12-25mm | 3mm (1/8") | 10mm (3/8") |
| 25-50mm | 4mm (5/32") | 13mm (1/2") |
| 50-100mm | 5mm (3/16") | 16mm (5/8") |
| > 100mm | 6mm (1/4") | 19mm (3/4") |
Understanding Weld Porosity
Types of Porosity
- Scattered: Uniformly distributed small pores - most common
- Clustered: Groups of pores in localized area - more serious
- Linear/Aligned: Pores in a line - indicates systematic problem
- Piping/Wormhole: Elongated tubular cavities - typically at start/stop
Causes of Porosity
- Gas Entrapment: Shielding gas disruption, contamination
- Surface Contaminants: Oil, rust, moisture, paint
- Electrode Issues: Wet electrodes, damaged flux coating
- Base Metal: High sulfur content, improper cleaning
- Welding Parameters: Arc too long, travel speed too fast
Prevention
- Clean base metal thoroughly before welding
- Store electrodes properly (dry, temperature controlled)
- Ensure adequate shielding gas flow and coverage
- Use proper welding technique and parameters
- Protect weld area from drafts