Visual Testing of Welds
Some of the areas of knowledge that are required to be dealt with as a Visual Weld Inspector:
- A. Welding processes
- B. Weld joint configuration
- C. Weld defects (as applicable to various processes)
- D. Weld procedures
- E. Welder qualification records
- F. Material certifications
- G. Filler metal requirements
- H. Material processing
- I. Prints
- J. Weld symbols
- K. Mechanical test
- L. Metallurgy
- M. NDE
- N. English and metric measurement practices
- O. Codes and standards as applicable
- P. Safety
Basic Definitions required for weld inspections.
- A. Actual Throat: The shortest distance between the weld root and the face of a fillet weld.
- B. Autogenous: Welds or welding complete without the use of filler material.
- C. AWS: American Welding Society.
- D. AWS D1.1: Structural Steel Welding Code provided by AWS.
- E. CWI: AWS Certified Welding Inspector.
- F. NDE, NDI, or NDT: The process of evaluating the suitability of a component for performance by a method that does not harm the component under examination. (NOTE: NDE is in most cases considered an indirect method of examination.)
- G. Discontinuity: An interruption of the typical structure of a material, such as a lack of homogeneity in its mechanical, metallurgical, or physical characteristics. A discontinuity is not necessarily a defect..
- H. Defect: An interruption in the normal configuration or condition of a material or article under examination that exceeds the applicable code or standard under which the examination is being performed. This term designates rejectability.
- I. Interpretation: To give meaning to. The practice of determining the proper term to associate with an observed condition.
- J. Evaluate: To determine worth. The practice of determining if an observed condition exceeds the applicable criteria for the given inspection.
- K. Quantitative examination: Determined through measurement or reproducible, quantity. An example would be a measurement taken with micrometers or calipers.
- L. Qualitative examination: Of quality. This examination may lead to results based on judgment or opinion and may not be based on a measurable quantity.
- M. Indication: Any area where a suspect condition is observed on the surface of a
component under examination. Indications may take various forms, and may be rounded, linear, jagged, smooth, continuous or broken. (Specific aspects of indications will be covered later).
- N. Non-relevant Indication: This may be argued, but in my opinion, an indication due to the normal aspects of a component under evaluation. This could be geometry, threads, splines, press-fit plugs, surface roughness, and press fit assemblies. For this study guide, an indication caused by an acceptable discontinuity will just be considered an acceptable discontinuity, and not non-relevant, to eliminate confusion.
- O. False Indication: An indication caused by incorrect processing, such as fingerprints, smudges, excessive contamination. False indications are those that are eliminated by correcting errors in processing.