This standard provides a reference guide for the kinds of nondestructive examination methods that are used to verify that welds meet the requirements of a code or specification. The nondestructive examination methods described are:

(1) Visual

(2) Penetrant

(3) Magnetic Particle

(4) Radiographic

(5) Ultrasonic

(6) Electromagnetic

(7) Leak

The types of discontinuities detected with each method are disclosed and their causes discussed. Acceptance criteria are not addressed in this standard. Such requirements may be in the application code. Requirements for nondestructive examination and acceptance criteria not provided in the application should be the specified in procurement documents prior the award of contracts.

Nondestructive examination (NDE) is a general term used in this text to identify the common inspection methods for evaluation of welds and related materials without destroying their usefulness.

The terminology used in this guide is that established in AWS A3.0, Standard Welding Terms and Definitions. That document defines a discontinuity as “an interruption of the typical structure of a material, such as a lack of homogeneity in the mechanical, metallurgical, or physical characteristics.” It defines discontinuity as a defect when it exceeds the sizes and types of discontinuities defined as rejectable by the applicable specification. For the purpose of this guide, reference will be made to detection of discontinuities without regard to the distinction between acceptance or rejection.

Principal factors to consider when choosing an inspection method are the advantages and limitations of the method, anticipated type and size of discontinuity, acceptance standards, and cost. Annex A is a guide to process selection.