3.1 Standard nomenclature shall be used to facilitate communication between designers, suppliers, and users of HVAC ventilation ductwork components.

3.2 Standard design parameters shall be used to define ventilation ductwork shapes.

3.3 Standard variables for design parameters (see 2.2) are useful in writing CAD/CAM software for automatic fabrication of ventilation ductwork shapes.

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. Straight:

 1.1 Straight-round

 1.2 Straight-flat oval

 1.3 Straight-rectangular

2. Offset:

 2.1 Offset-round

 2.2.1 Offset-flat oval-long axis

 2.2.2 Offset-flat oval-short axis

 2.3.1 Offset-rectangular-without splitters

 2.3.2 Offset-rectangular-with splitters

 2.4.1 Offset-ogee-without splitters

 2.4.2 Offset-ogee-with splitters

 2.5.1 Offset-rectangular reducing-without

 splitters

 2.5.2 Offset-rectangular reducing-with splitters

3. Elbow:

 3.1 Elbow-round

 3.2.1 Elbow-flat oval-long axis

 3.2.2 Elbow-flat oval-short axis

 3.3.1 Elbow-rectangular-without splitters

 3.3.2 Elbow-rectangular-with splitters

 3.4.1 Elbow-rectangular reducing-without

 splitters

 3.4.2 Elbow-rectangular reducing-with splitters

 3.5.1 Elbow-rectangular transition-without

 splitters

 3.5.2 Elbow-rectangular transition-with splitters

4. Vaned Turn:

 4.1 Vaned turn

5. Reducer:

 5.1 Reducer-round

 5.2 Reducer-flat oval

 5.3 Reducer-rectangular

6. Transition and Bellmouth:

 6.1 Transition-flat oval to round

 6.2 Transition-rectangular to round

 6.3 Transition-rectangular to flat oval

 6.4 Transition-rectangular to radius corner

 6.5 Transition-radius corner to flat oval

 6.6.1 Bellmouth-round

 6.6.2 Bellmouth-rectangular

7. Branch:

 7.1.1 Branch-round-on equal diameter round

 7.1.2 Branch-round-on larger diameter round

 7.1.3 Branch-round-on round reducer

 7.1.4 Branch-round-on rectangular straight

 7.1.5 Branch-round-on rectangular reducer

 7.1.6 Branch-round “Y”

 7.1.7 Branch-rectangular to round-“Y”

 7.2.1 Branch-rectangular-on rectangular straight

 7.2.2 Branch-rectangular-on rectangular reducer

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 are used.

1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.