AWS B1.10:2016

This guide acquaints the user with the nondestructive examination methods commonly used to examine weldments. The standard also addresses which method best detects various types of discontinuities. The methods included are visual, liquid penetrant, magnetic particle, radiographic, ultrasonic, electromagnetic (eddy current), and leak testing
Scope : 1.1 Scope. 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 (VT) (2) Liquid Penetrant (PT) (3) Magnetic Particle (MT) (4) Radiographic (RT) (5) Ultrasonic (UT) (6) Electromagnetic (Eddy Current) (ET) (7) Leak (LT) The types of discontinuities detected with each method and their causes are discussed. Acceptance criteria are not addressed in this standard. Requirements for nondestructive examination and acceptance criteria should be specified in procurement documents prior to the award of contracts. Principal factors to consider when choosing an examination 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. 1.2 Advantages and Limitations of the Examination Method. The advantages and limitations of the examination method help to determine which method(s) is (are) best for detecting discontinuities of a particular size, shape, and orientation. For example, radiography can detect discontinuities with major planes aligned parallel with the radiation beam, such as cracks oriented normal to material surfaces. Radiography, however, usually cannot detect laminations immaterial or cracks oriented parallel to the plate surface. Conversely, ultrasonic examination can detect cracks oriented in any direction provided the sound beam is oriented essentially perpendicular to the major axis of the crack. 1.3 Acceptance Standards. The statement â??the weld shall be radiographically examinedâ? is incomplete unless acceptance standards are specified. Acceptance standards define characteristics of discontinuities. They also establish upper and lower limits that determine the acceptance or rejection of a given discontinuity in conformance with the applicable acceptance standard. Discontinuities may be acceptable providing their size and distribution are within specified limits. Some acceptance standards are shown in Annex C. 1.4 Cost. Costs of the various examination methods depend on the particular situation. Two factors that should be considered in selection of a nondestructive examination method are the cost of performing the examination and of the equipment. Visual examination is usually the least expensive, but it is limited to the detection of surface discontinuities. In general, the cost of radiography, ultrasonic, or eddy current examination is higher than the cost of visual, magnetic particle, or liquid penetrant examination. To determine the method(s) that will best satisfy the intended purpose and minimize cost, qualified personnel should be consulted. 1.5 Procedures. It should be recognized that all NDE methods must be performed in accordance with an approved procedure which is available to the technician performing the test or examination. This is almost always a requirement of the applicable code. Only by following a documented (written) procedure can the NDE technician ensure adherence to codes and specifications applicable to the fabrication under test. These procedures should be documented to provide all details of test preparation, performance, and interpretation to ensure reliability and reproducibility of results. 1.6 NDE Symbols. The use of NDE symbols and abbreviations is shown in Annex B, which is adapted from AWS A2.4, Standard Symbols for Welding, Brazing, and Nondestructive Examination. 1.7 Standard Units of Measurement. This standard makes use of both the International System of Units (SI) and U.S. Customary Units. The latter are shown within brackets ([]) or in appropriate columns in tables and figures. The measurements may not be exact equivalents; therefore, each system must be used independently. 1.8 Safety and Health. Safety issues and concerns are beyond the scope of this standard and therefore are not fully addressed herein. Safety and health information is available from the following sources: American Welding Society: (1) ANSI Z49.1, Safety in Welding, Cutting, and Allied Processes (2) AWS Safety and Health Fact Sheets (3) Other safety and health information on the AWS website Material or Equipment Manufacturers: (1) Safety Data Sheets supplied by materials manufacturers (2) Operating Manuals supplied by equipment manufacturers Applicable Regulatory Agencies U.S. Department of Labor Regulations: (1) CFR-29, Part 1910.107 Spray Finishing using Flammable and Combustible Liquids. Work performed in accordance with this standard may involve the use of materials that have been deemed hazardous, and may involve operations or equipment that may cause injury or death. This standard does not purport to address all safety and health risks that may be encountered. The user of this standard should establish an appropriate safety program to address such risks as well as to meet applicable regulatory requirements. ANSI Z49.1 should be considered when developing the safety program.