AWS D9.1 PDF

This Specification covers welding as it applies to the fabrication and erection of non-structural sheet metal heating, ventilation, and air-conditioning systems; architectural usage; food-processing equipment; and similar applications. Where pressures or vacuums of more than 120 inches of water gauge pressure (4 psig) or where structural requirements are concerned, other standards are to be used.

The attachment of any members whose sole purpose is stiffening, supporting, or reinforcing of the sheet metal material is also addressed in this Specification as well as the attachment of accessories or components of the system.