SHARBATHAT Oman

ASME Code Welding Requirements

ASME (American Society of Mechanical Engineers) sets stringent requirements for welding in the construction of pressure vessels and other critical components. These requirements are outlined in detail within ASME Section IX, which focuses on welding, brazing, and fusing qualifications.  

Here are some of the key requirements:

1. Welding Procedure Specifications (WPS):

• Development: A detailed WPS must be developed for each specific welding process, material combination, and joint configuration.  
• Qualification: The WPS must be qualified through rigorous performance qualification tests (PQTs) to demonstrate that it produces welds with the required strength, ductility, and other critical properties.  
• Parameters: The WPS must specify critical welding parameters such as:
  • Welding process: (e.g., SMAW, GMAW, GTAW)  
  • Base materials: Type and grade of metals being joined
  • Filler metals: Type and size of welding rods or wires
  • Welding positions: (e.g., flat, horizontal, vertical, overhead)
  • Pre-heat and post-weld heat treatment: Temperature and duration of any required heat treatments
  • Welding parameters: Voltage, amperage, travel speed, and other relevant settings

2. Welder/Operator Qualification:

• Certification: Welders and operators must be qualified to perform welding according to the approved WPS.  
• Qualification Tests: Welders must pass a series of qualification tests, including:
  • Practical tests: Demonstrating the ability to produce sound welds according to the WPS.
  • Written examinations: Demonstrating knowledge of welding principles, safety practices, and code requirements.
• Record Keeping: Welder qualifications must be documented and maintained, including records of all qualification tests and performance evaluations.  

3. Material Control:

• Material Traceability: Materials used in welding must be properly identified and traceable to their source.  
• Material Certification: Material certificates must be provided to verify the chemical composition and mechanical properties of the base materials.  

4. Welding Process Control:

• Procedure Compliance: Welders must strictly adhere to the approved WPS during welding operations.  
• Visual Inspection: Visual inspections must be performed throughout the welding process to identify and correct any defects.  
• Non-Destructive Examination (NDE): NDE methods such as radiography, ultrasonic testing, and magnetic particle testing must be performed to detect internal defects in welds.  

5. Post-Weld Heat Treatment (PWHT):

• Requirements: If required by the WPS or code, PWHT must be performed to relieve residual stresses and improve the toughness of the weld.  
• Control: PWHT procedures must be carefully controlled to ensure that the required temperature and holding time are achieved.  

6. Documentation:

• Complete Records: Detailed records must be maintained for all aspects of the welding process, including:
  • WPSs and welder qualifications  
  • Inspection reports
  • NDE results
  • Heat treatment records
  • Material certifications

Importance of ASME Code Welding Requirements:

• Safety: Ensure the safety and integrity of pressure vessels and other critical components.
• Quality: Produce high-quality welds that meet the required strength, ductility, and other performance criteria.  
• Compliance: Ensure compliance with ASME standards and other relevant regulations.
• Reliability: Enhance the reliability and longevity of welded structures.