What is Welding Inspection & Stages of Welding Inspection

Welding Inspection, what it means?

Weld inspection begins long before the first welding arc is struck on the job. A welding inspector must review the job package to become familiar with the:

  • welding processes to be used;
  • materials and any special properties;
  • joint configurations and preparation;
  • welding procedure specifications to be used and any limitations;
  • qualifications of welders to be used and any limitations;
  • heat treatment (pre-heat or post-weld heat treatment), if any;
  • nondestructive examination (NDE), if any; and
  • specific ASME Code or NBIC requirements (for example, Section VIII, Div. 1, lethal service).
fillet weld measurement

Importance of Welding Inspection & Welding Inspector

While not imperative, the inspector should learn to read common weld symbols such as the AWS symbols. At the very least, the inspector should always carry a reference guide to interpret weld symbols. Having reviewed all this information in advance, the inspector will be prepared to recognize any problems as they develop rather than after-the-fact. Welding inspection includes much more than just the non-destructive examination of the completed weld. Many other issues are important, such as:

  1. review of specifications,
  2. joint design,
  3. cleaning procedures, and
  4. welding procedures.
  5. Welder qualifications

All above steps should be performed to better assure that the weldment performs properly in service.

Stage of Welding Inspection

Welding inspection activities can be separated into three stages corresponding to the welding work process. Inspectors should perform specific tasks:

  1. prior to welding,
  2. during welding and
  3. upon completion of welding.

Welding Inspection before welding:

root gap inspection

The importance of tasks in the planning and weld preparation stage should not be understated. Many welding problems can be avoided during this stage when it is easier to make changes and corrections, rather than after the welding is in progress or completed. Such tasks may include:

  1. Drawings, Codes, and Standards: Review drawings, standards, codes, and specifications to both understand the requirements for the weldment and identify any inconsistencies.
  2. Weldment Requirements Review requirements for the weldment with the personnel involved with executing the work such as the design engineer, welding engineer, welding organization and inspection organization.
  3. Procedures and Qualification Records Review the WPS(s) and welder performance qualification record(s) (WPQ) to assure they are acceptable for the work.
  4. NDE Information Confirm the NDE examiner(s), NDE procedure(s) and NDE equipment of the inspection organization are acceptable for the work.
  5. Welding Equipment and Instruments Confirm welding equipment and instruments are calibrated and operate.
  6. Heat Treatment and Pressure Testing Confirm heat treatment and pressure testing procedures and associated equipment are acceptable.
  7. Materials Ensure all filler metals, base materials, and backing ring materials are properly marked and identified and if required, perform PMI to verify the material composition.
  8. Weld Preparation Confirm weld preparation, joint fit-up, and dimensions are acceptable and correct.
  9. Preheat Confirm the preheat equipment and temperature.
  10. Welding Consumables Confirm electrode, filler wire, fluxes, and inert gases are as specified and acceptable.

Welding Inspection during welding:

tack welding

Welding inspection during welding operations should include audit parameters to verify the welding is performed to the procedures. Such tasks may include the following:

  1. Quality Assurance Establish quality assurance and quality control umbrella with the welding organization.
  2. Welding Parameters and Techniques Confirm welding parameters and techniques are supported by the WPS and WPQ.
  3. Weldment Examination Complete physical checks, visual examination, and in-process NDE.

Welding Inspection after competition of weld

visual inspection

Final tasks upon completion of the weldment and work should include those that assure final weld quality before placing the weldment in service.

  1. Appearance and Finish Verify post-weld acceptance, appearance and finishing of the welded joints.
  2. NDE Review Verify NDE is performed at selected locations and review examiner’s findings.
  3. Post-weld Heat Treatment Verify post-weld heat treatment is performed to the procedure and produces acceptable results.
  4. Documentation Audit Perform a final audit of the inspection dossier to identify inaccuracies and incomplete information.

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