1.1 This practice covers the identification of design configurations and descriptive nomenclature for sheetmetal HVAC ductwork shapes frequently used in shipbuilding. This practice also covers parametric dimensions of these shapes. (See Table 1.)1.2 This practice does not cover the location of seams or joints within a shape or the method of joining shapes together. 1.3 Since this practice is not measurement sensitive, it is applicable whether inch-pound or SI metric dimensions a