Welding Procedure Qualification Skill

Purpose

The Welding Procedure Qualification skill provides capabilities for developing and qualifying welding procedures per AWS and ASME codes, enabling compliant welding documentation and welder certification.

Capabilities

• WPS (Welding Procedure Specification) development
• PQR (Procedure Qualification Record) documentation
• Essential variable identification and ranges
• Welder qualification requirements
• Filler metal and consumable selection
• Preheat and interpass temperature specification
• NDT requirement specification
• Code compliance verification (AWS D1.1, ASME IX)

Usage Guidelines

Welding Process Selection

Common Processes

Process Selection Criteria

Consider:
- Base metal type and thickness
- Joint configuration
- Position requirements
- Production volume
- Quality requirements
- Welder skill availability
- Equipment availability

WPS Development

Essential Variables (ASME IX)

WPS Content Requirements

1. Identification
   - WPS number
   - Revision
   - Supporting PQR(s)

2. Joint Design
   - Type (butt, fillet, etc.)
   - Groove angle
   - Root opening
   - Root face
   - Backing (if used)

3. Base Metal
   - Specification
   - P-number/Group
   - Thickness range

4. Filler Metal
   - Specification
   - F-number
   - A-number
   - Size range

5. Position
   - Qualified positions
   - Progression (vertical)

6. Preheat/Interpass
   - Minimum preheat
   - Maximum interpass

7. Welding Parameters
   - Current type/polarity
   - Amperage range
   - Voltage range
   - Travel speed range

8. Technique
   - String vs weave
   - Single vs multi-pass
   - Cleaning method

9. PWHT
   - Temperature range
   - Time at temperature
   - Heating/cooling rates

PQR Documentation

Required Testing

Test Specimen Requirements

Groove Welds:
- 2 tensile specimens
- 4 bend specimens (2 face, 2 root or 4 side)
- Impact specimens (if required)

Fillet Welds:
- Macro examination
- Fillet weld break test

Welder Qualification

WPQ Requirements

Welder Performance Qualification:
- Based on qualified WPS
- Position-specific
- Thickness range qualified
- Process-specific
- Maintenance requirements (typically 6 months)

Position Qualification

Filler Metal Selection

AWS Classification System

E70XX (SMAW):
E = Electrode
70 = Tensile strength (70 ksi)
XX = Position and coating type

ER70S-X (GMAW/GTAW):
E = Electrode
R = Rod
70 = Tensile strength
S = Solid wire
X = Specific chemistry

Common Filler Metals

Preheat and PWHT

Preheat Requirements

Factors affecting preheat:
- Carbon equivalent
- Base metal thickness
- Hydrogen content
- Restraint level
- Ambient temperature

Carbon Equivalent (IIW):
CE = C + Mn/6 + (Cr+Mo+V)/5 + (Ni+Cu)/15

CE > 0.45: Preheat required

PWHT Requirements

Process Integration

• ME-020: Welding Procedure Qualification

Input Schema

{
  "base_metal": {
    "specification": "string",
    "p_number": "number",
    "thickness": "number (mm)"
  },
  "joint_design": {
    "type": "butt|fillet|corner|tee",
    "groove_type": "V|U|J|bevel",
    "position": "1G|2G|3G|4G|5G|6G"
  },
  "applicable_code": "AWS_D1.1|ASME_IX|ASME_B31.3",
  "quality_requirements": {
    "ndt_required": "array",
    "impact_required": "boolean",
    "design_temperature": "number (C)"
  }
}

Output Schema

{
  "wps_draft": {
    "wps_number": "string",
    "process": "string",
    "joint_design": "object",
    "filler_metal": "object",
    "parameters": "object",
    "preheat": "object",
    "pwht": "object"
  },
  "pqr_requirements": {
    "test_specimens": "array",
    "acceptance_criteria": "object",
    "test_laboratory": "string"
  },
  "welder_qualification": {
    "wpq_required": "boolean",
    "positions": "array",
    "essential_skills": "array"
  },
  "code_references": "array"
}

Best Practices

1. Always work from the applicable code requirements
2. Document all essential variables completely
3. Maintain traceability of filler metal certifications
4. Keep welder qualifications current
5. Review WPS before production welding
6. Archive all qualification records

Integration Points

• Connects with Material Selection for weldability
• Feeds into FAI Inspection for weld inspection
• Supports Design Review for joint details
• Integrates with Quality for procedure control