Rectangular Duct And Fittings

Question 1

This is found on the front of a circumference ruler?

Answer 1

Inches and stretch outs on the bottom

Question 2

What can be used to find a specific angle?

Answer 2

Protractor

Question 3

What is the purpose of cross breaks?

Answer 3

To reinforce metal usually 12 inch and over

Question 4

What is the difference between a net and gross pattern

Answer 4

Net means no allowances
Gross is with allowance

Question 5

When using a box and pan brake what steps must be taken before using?

Answer 5

Adjust fingers and clamping pressure

Question 6

Why do we cross brake?

Answer 6

For stiffness

Question 7

At what measurement should we start cross breaking?

Answer 7

Over 12 inch

Question 8

A curved cheek should have what for a Pittsburgh allowance on its curved portion?

Answer 8

3/16

Question 9

What allowance is used on a straight portion of duct for a Pittsburgh joint?

Answer 9

1/4

Question 10

What are the heel and throat called
That join the cheeks together to make an elbow?

Answer 10

Runners or wrappers

Question 11

What should you do to a wrapper or runner before putting on the pittsburgh?

Answer 11

Pre roll it

Question 12

What is the allowance per end for slip and drive of duct?

Answer 12

1/2

Question 13

What should be done to the transition sloping end on the 1 inch ends?

Answer 13

Kinks or correction bends

Question 14

Where is the TDC put on a piece of duct?

Answer 14

Raw edge

Question 15

Where is the drive put on a piece of duct?

Answer 15

Short side

Question 16

What is one reason for using a proprietary connection?

Answer 16

Adequate seal for high pressure system

Question 17

To adjust blanks and patterns for growth you remove how much?

Answer 17

1/16 per joint

Question 18

What is the purpose of a canvas connection?

Answer 18

To provide isolation of sound

Question 19

Can fire dampers be modified?

Answer 19

No

Question 20

How much smaller is a first damper made to fit in a sleeve?

Answer 20

1/4

Question 21

Hoe much of the fire damper sleeve should stick through the wall minimum and maximum?

Answer 21

Min 3 inch
Max 6 inch

Question 22

When connecting a fire damper sleeve to the duct work what must it have?

Answer 22

A break away joint

Question 23

What is the minimum gauge of a fire damper sleeve?

Answer 23

22 ga