HVAC Sheet Metal and Fabrication 3

Question 1

When using aviation snips to cut sheet metal, which color handle is used for straight cuts?

Accepted Answer

Yellow

Answer

Yellow-handled aviation snips are designed for straight and wide-curve cuts in sheet metal.

Question 2

What is the correct bend allowance concept used when laying out a sheet metal fitting?

Accepted Answer

Extra material must be added to account for metal that stretches during bending

Answer

Bend allowance accounts for the arc length of metal at the neutral axis during bending, so extra flat length is included in the pattern.

Question 3

Which duct sealing class per SMACNA requires sealing all transverse joints, longitudinal seams, and duct wall penetrations?

Accepted Answer

Class A

Answer

SMACNA Seal Class A requires sealing all transverse joints, longitudinal seams, and duct wall penetrations for the highest level of airtightness.

Question 4

What type of fitting connects a rectangular duct to a round duct?

Accepted Answer

Transition fitting

Answer

A transition fitting (also called a square-to-round transition) is used to connect rectangular and round duct sections.

Question 5

In sheet metal layout, what tool is used to scribe a parallel line at a fixed distance from a straight edge?

Accepted Answer

Dividers or a scratch awl with a straightedge

Answer

Dividers or a scratch awl guided along a straightedge are used to scribe accurate parallel layout lines on sheet metal.

HVAC Practice Test