AWS D18.1/D18.1M PDF

This specification covers the requirements for gas tungsten arc welding (GTAW) and plasma arc welding (PAW) of stainless steel tube and pipe 1/4 in [6 mm] diameter and larger in the fabrication and construction of new sanitary (hygienic) processing systems. This specification includes the welding of tube and pipe for the transportation of sanitary (hygienic) system products and cleaning or sanitizing solutions. It includes manual welding as well as mechanized or automatic welding, such as orbital welding. This specification addresses welding procedure and performance qualification as well as visual examination requirements for as-welded surfaces and finished surfaces.

This specification is intended for new construction. However, the requirements may also be applied to maintenance and repair of food processing equipment. When there is a conflict between this specification and a design specification to which the equipment is being constructed, the applicable code shall govern on issues that apply to structural design or structural integrity. This specification does not address requirements designed to prevent corrosion damage during service or any structural design or integrity aspects of components or systems used for sanitary (hygienic) applications.

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 dairy, meat, poultry, vegetables, beverages, personal care items (such as shampoo, soap, toothpaste, cosmetics), and other products consumed or used by humans or animals, which require freedom from contamination.

When this specification is stipulated in contract documents, conformance with all provisions of this specification is required except provisions specifically modified or exempted by the Owner, their representative, or the contract documents.