Codes, regulatory requirements, standards, specifications and recommended practices are used in all aspects of construction, fabrication, manufacturing and inspection. The following is a brief description of each of these categories along with examples of how they are used.
Codes are generally the top-tier documents, providing a set of rules that specify the minimum acceptable level of safety for manufactured, fabricated or constructed objects. These may incorporate regulatory requirements and will often refer out to standards or specifications for specific details on additional requirements not specified in the Code itself. Examples of some commonly used Codes are the ASME Boiler and Pressure Vessel Code (B&PVC) and the AWS D1.1 Structural Welding Code – Steel. The B&PVC covers pressure-related equipment from refineries and unfired pressure vessels to nuclear power generation, and the AWS D1.1 Code covers welded structures of all types.
Regulations are generally issued by a state or federal agency when public safety is an issue. Examples of such regulatory agencies and their regulations are the Nuclear Regulatory Commission (NRC), whose regulations are found in the Code of Federal Regulations, Title 10, Parts 0-50 (10 CFR 0-50). These regulations cover the use and handling of radioactive materials, and the NRC has significant input into Sections III and XI of the ASME B&PVC, which cover new nuclear construction and in-service inspection of existing nuclear power plants. The Occupational Safety and Health Administration (OSHA) provides rules for personnel safety on job sites, and the U.S. Department of Transportation (USDOT) provides regulations for pipelines and hazardous materials in 49 CFR 100-199.
Standards are documents that establish engineering or technical requirements for products, practices, methods or operations. Of particular interest to NDT personnel are those standards that provide personnel certification requirements and those that provide requirements for performing NDT tasks. Examples of certification standards are the ANSI/ASNT CP-189, ASNT Standard for Qualification and Certification of Nondestructive Testing Personnel and the ANSI/ASNT CP-105, ASNT Standard Topical Outlines for Qualification of Nondestructive Testing Personnel. Examples of NDT performance standards are the ASTM Standard E 709, Standard Guide for Magnetic Particle Testing, and ASTM E 1444, Standard Practice for Magnetic Particle Testing.
Specifications provide specific requirements for materials, components or services and are often generated by private companies to address additional requirements applicable to a specific product or application. Specifications are often listed in procurement agreements or contract documents as additional requirements above and beyond code or standard requirements.
Recommended practices provide guidelines for performing operations or functions. The most commonly used recommended practice for NDT personnel certification worldwide is the ASNT Recommended Practice No. SNT-TC-1A. This document, commonly referred to as "SNT-TC-1A," provides guidelines for employers to set up an in-house certification program for their personnel. The premise is that employers will incorporate the guidelines that apply to their specific needs into their written practice, at which point those guidelines become that company's requirements for the certification of their NDT personnel. For more information on SNT-TC-1A-based and other certification systems, go to the NDT Certification page.
For more information on many of the commonly used codes and standards, go to the Codes and Standards Bodies web page.