AWS D18.3/D18.3M:2015

This specification provides the requirements for welding of tanks, vessels, and other equipment used in food processing plants and other areas where sanitary (hygienic) applications are required. The document addresses qualification, fabrication, extent of visual examination, acceptance criteria, and documentation requirements.
Scope : This specification covers the requirements for welding of stainless steels and nickel alloys (as well as carbon steels and other metals for some applications) in sheet, plate, bar, and other forms for the fabrication and construction of new tanks, vessels, and other equipment in sanitary (hygienic) applications. The welding of pipe or tube to a tank, vessel or other piece of sanitary equipment, for use as a nozzle or other opening, is included in this specification. This specification excludes the welding of tube and pipe for the transportation of sanitary (hygienic) system products and cleaning or sanitizing solutions. Pipe and tube welding for sanitary (hygienic) systems is covered in AWS D18.1, Specification for Welding of Austenitic Stainless Steel Tube and Pipe Systems in Sanitary (Hygienic) Applications. This specification is intended for new construction and may also be applied to maintenance and repair of equipment in sanitary (hygienic) applications. This specification does not address structural, pressure design nor corrosion aspects of components and systems. However requirements in this specification should be applied in conjunction with other governing requirements. Sanitary processing systems are intended to include those systems handling products for human and animal consumption, or for cleaning and sanitizing solutions used in these systems. Such products include, but are not limited to, dairy, meat, poultry, vegetable, beverage, personal care items (such as shampoo, soap, toothpaste, cosmetics), and other products consumed or used by humans and animals. This specification may be used, in whole or in part, for other applications where hygienic fabrication is desired. This specification addresses welding qualification and visual examination requirements for as-welded surfaces as well as finished surfaces. 1.2 Units of Measure. This standard makes use of both U.S. Customary units and the International System of Units (SI). The latter are shown within brackets ([ ]) or in appropriate columns in tables or figures. The measurements may not be exact equivalents; therefore each system must be used independently.1.3 Safety. Safety and health issues and concerns are beyond the scope of this standard; some safety and health information is provided, but such issues 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 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. 1.4 Ownerâ??s Responsibility. The Owner or their representatives shall provide a complete specification for the equipment and shall identify surface classification zones (product-contact surface zones and non-product-contact surface zones) and weld finishes for each surface classification zone. Owners should use Figure 1 to specify surface classification zones and Annex B to designate the required weld finish of each zone. 1.5 Welding Symbols. Welding symbols shall be those shown in the latest edition of AWS A2.4, Standard Symbols for Welding, Brazing, and Nondestructive Examination. Special conditions shall be fully explained by added notes or details.