A Comprehensive Guide to NDT CODES & STANDARDS

• Codes are generally the governing documents, providing a set of rules that specify the minimum acceptable level of safety for manufactured, fabricated, or constructed objects.
• Most codes will provide acceptance and rejection criteria for the required inspections.
• ASME (American Society of Mechanical Engineers) Codes are legally enforceable in many US states. Whereas, in the other part of the world they are not legally enforceable, but such countries have their own similar codes.

• Standards are the documents, prepared by professional societies or committee, which are believed to be efficient engineering practices and which contain mandatory requirements.
• An inspection standard may include information on how to apply multiple testing techniques.
• Standardization of certain items to prevent multiple versions to be used.
• Standards are usually created by individual companies, organizations, or countries. They are not legalized.

A “GUIDE”

is a compendium of information or series of options that does not recommend a specific course of action. A guide increases the awareness of information and approaches in each subject area.

A “PRACTICE”

is a definitive set of instructions for performing one or more specific operations or functions that does not produce a test result. Examples of practices include, but are not limited to application, assessment, cleaning, collection, decontamination, inspection, installation, preparation, sampling, screening and training.

A “TEST METHOD”

is a definitive procedure that produces a test result. Examples of test methods include, but are not limited to identification, measurement and evaluation of one or more qualities, characteristics or properties.

Here are the most used ASTM NDT standards. Additional standards could be sourced in the ASTM Annual Book of Standards, Volume 03.03.

www.astm.org

ASME B31.1: Power Piping. This code contains requirements for piping systems typically found in electric power-generating stations, industrial institutional plants, geothermal heating systems, and heating and cooling systems.

ASME B31.3: Process Piping. This Code contains requirements for piping typically found in petroleum refineries; chemical, pharmaceutical, textile, paper, semiconductor, and cryogenic plants; and related processing-plant terminals.

www.asme.org

www.api.org

is a nonprofit organization with the goal of advancing the science, technology, and application of welding and related joining disciplines. AWS provides certification programs for welding inspectors, supervisors, educators, etc., and publishes multiple standards, many of which contain procedures for the application of nondestructive testing methods and techniques above and beyond visual inspection. A few of their standards are listed here:

www.aws.org

the world’s largest developer and publisher of International Standards, is a non-governmental organization located in Geneva, Switzerland. ISO is a network of the national standards institutes of 161 countries, one member per country. Many of the ISO member institutes are part of the governmental structure of their countries or are mandated by their government. Other members have their roots uniquely in the private sector, having been set up by national partnerships of industry associations. Three of the many ISO standards are listed below:

www.iso.org

NAS 410, NAS Certification & Qualification of Nondestructive Test Personnel. This employer-based certification standard establishes the minimum requirements for the qualification and certification of personnel performing nondestructive testing (NDT), nondestructive inspection (NDI), or nondestructive evaluation (NDE) in the aerospace manufacturing, service, maintenance, and overhaul industries. In 2002, NAS 410 was harmonized with European Norm 4179 (listed in the CEN section), so that the requirements in both documents are identical.

NAS 999, Nondestructive Inspection of Advanced Composite Structures. This specification establishes the requirements for non-destructive inspection (NDI), NDI standards, NDI methods, and NDI acceptance criteria.

www.aia-aerospace.org

Standards (Norms) developed by CEN are considered “harmonized standards” that are required to be accepted by all member nations in the European Union. The following two ENs are NDT certification standards:

EN 4179, Aerospace series – Qualification and approval of personnel for non-destructive testing. This employer-based certification standard is the European version of NAS 410, which was described under the Aerospace Industries Association section on this web page.

EN 473, Non-destructive testing – Qualification and certification of NDT personnel – General principles. This European Standard established principles for the third-party (“central”) qualification and certification of personnel who perform industrial non-destructive testing (NDT) by an accredited third-party certification body. Under EN 473, certification bodies had to administer procedures for certification according to the requirements of EN 473 and must fulfill the requirements of EN ISO/IEC 17024.

EN ISO 9712, which was approved in June 2012, replaced EN 473 as the European harmonized standard (Norm) for NDT central certification effective 1 January 2012. EN ISO 9712 permits the use of current EN 473 certifications until the certificate holders’ next renewal period, at which time they must recertify in accordance with the EN ISO 9712 requirements. EN ISO 9712 and ISO 9712 are identical except that EN ISO 9712 has been approved as a harmonized standard for use under the European Pressure Equipment Directive 97/23/EC.

www.cen.eu