03213 Sheet Metal Duct Systems: Module 9

When steel is galvanized, the galvanizing process is a form of a(n)_?

Coating

An advantage of using galvanized sheet metal over other materials when assembling a duct system is it_?

Is resistant to corrosion

When steel is rolled while it is cold, it_?

Gains tensile strength

The grooved lock seam is also known as a(n)_?

Acme, or pipe lock

A drive is put in place with a(n)_?

Hammer

What type of duct connector contains an additional hem reinforcement?

Standing S

Ducts OVER 60 inches wide must be supported with_?

Trapeze hangers

Ducts UP TO 60 inches wide must be supported with_?

Strap hangers

What is the maximum distance that a riser should be located away from the wall?

2 inches

In which application is fibrous glass duct liner NOT approved?

Hospital rooms

Which of the following can help reduce discomfort from embedded glass fibers when working with fiberglass insulation products?

Apply talcum powder before beginning

How much additional length must be added to 1 1/2 inch thick insulation being wrapped around a rectangular duct?

8 inches

When applying duct insulation with the adhesive method, how far apart should strips of adhesive be applied around the outside of a duct?

6 inches

The need for breakaway connections on ducts connected to fire damper sleeves is based on the_?

Size of the damper

What damper is the best choice when fully open and fully closed are the primary damper positions?

Parallel blade

Extractors our devices used with_?

Take-offs

Flexible duct is typically available in diameter up to_?

20 inches

Which of the following is a correct statement?

Flexible duct can be compressed so that a long section can fit into a much smaller box

How many wraps of duct tape must be made around a flexible duct when it is attached to a round collar?

2

What is the minimum width of support straps used to hang flexible ducts?

1-1/2 inches

The following questions are, "bonus questions," that might prove useful for study.

In which application is fibrous glass duct lines not approved?

Operating temperature of 250°F may be exceeded

Which of the following is an alloy?

Stainless steel

Steel is made up of iron and_?

Carbon

Which of the following connects branch ducts to the main trunk duct?

Hammerlock

When selecting sheet metal, a higher gauge indicates a(n)?

Thinner steel

If a wall or another duct is blocking the side of the duct were a manual volume damper must be installed the shaft for the damper quadrant should be located?

On the unblocked side

Sheet steel, cold-rolled steel, and copper are examples of__ metal?

Basic

Which of the following controls the spread of smoke in flames within an air distribution system?

Dampers

When measuring the thickness of coded sheet metal, the installer should?

Use one gauge thinner than the measurement

When installing fiber us glass duct lining, adhesive must be reinforced with?

Mechanical fasteners

Vertical duct runs are known as?

Risers

The sound power level is a rating that specifies?

The amount of sound a fan will produce

What may be required to reduce noise in an HVAC system?

Sound attenuation

When cutting 1 1/2 inch blanket insulation for round or oval duct you would add___ inches to the duct circumference to determine the length of the duct?

10 inches

When inspecting the installation of registers, grills and diffusers, which of the following must be true?

The duct or sleeve is flush with the finished wall

Which of the following is the most common seam fabricated in the sheet metal shop prior to duct assembly?

Pittsburgh lock

Which of the following duct connection illuminates the need for further reinforcement?

Standing seam

Which of the following is a direct factor in the air leakage for a system?

Seam and joint types

Sheet steel, cold-rolled steel and copper are examples of what type of metals?

Basic metals

Which of the following can help reduce discomfort from embedded glass fibers when working with fiberglass insulation products?

Rinsing the skin or showering and cool or cold water

1 inch light gauge metal straps are often used to suspend?

Round duct

Sheet metal is available in 26 gauge and 20 gauge. What is the difference between the two?

20 gauge is thicker than 26 gauge

What is the maximum allowable SAG beween supports for flexible duct?

1 inch per foot

Which seem is commonly used as a cross- seam and large ducts since it adds reinforcement?

Standing seam

Fasteners heads must compress the insulation know more then?

1/8 inch

Dampers close automatically with a?

Spring

The Fire Rating for fire dampers is specified in?

Hours