Pattern Development

Question 1

What are the most common triangulated fittings?

Answer 1

Top Takeoff, End Boot and Garbage Chute

Question 2

When is a face line used ?

Answer 2

When triangulating a transitional Y-Branch

Question 3

What is a foreshortened line?

Answer 3

A line that appears shorter than it actually is.

Question 4

When determining the VH (vertical height) for a pattern all seams and allowances must be _________.

Answer 4

Subtracted.

Question 5

How much of the pattern of an on centre both ways square to round needs to be developed ?

Answer 5

1/4 pattern

Question 6

What view is necessary to develop a square or rectangular to round fitting ?

Answer 6

Plan view.

Question 7

Transitional elbows are most commonly found in __________ installations.

Answer 7

Commercial

Question 8

What are the benefits of transitional elbows ?

Answer 8

direction, dimension and elevation can be changed with one fitting

Question 9

In transitional ogee offsets the vertical height of the sloped pattern is obtained from the sloped length of the ________

Answer 9

Runners

Question 10

Why are transitions necessary ?

Answer 10

Transitions are necessary to change the size and or position of the main trunk to maintain the required amount of airflow

Question 11

Twists serve the same purpose as ________

Answer 11

Transitions.

Question 12

The vertical height of transitions and twists is the height of he fitting minus any ________ and ________.

Answer 12

Collars and Allowances

Question 13

Cheek patterns for transitional y-branches are developed from the _________ view.

Answer 13

Elevation view

Question 14

Multiple branch fittings are typically used in _______ systems

Answer 14

Blowpipe systems

Question 15

How are 3 way branches triangulated ?

Answer 15

Chord offsets

Question 16

What is the simplest form of triangulation?

Answer 16

Triangulation from plan view

Question 17

The round collar pattern must be developed ______in order to determine the distance from point to point as you work your way around the round opening

Answer 17

First

Question 18

Rectangle to round on patch fittings are found on what type of roofs ?

Answer 18

Pitch roofs only

Question 19

What is an advantage of rectangle to round offsets ?

Answer 19

Combine 2 fittings into 1

Question 20

Triangulation from elevation uses what views ?

Answer 20

Elevation and Plan View

Question 21

When the fitting is on Centre the work line is always located ______ the depth of the rectangular opening as seen in the plan view.

Answer 21

1/2

Question 22

Where are garbage chutes found ?

Answer 22

Older apartment buildings or small apartment blocks

Question 23

Where is rectangle to round used in residential?

Answer 23

End boots

Question 24

If the work line falls within the plan view you continue the ______ development

Answer 24

Pattern

Question 25

What is a chord offset ?

Answer 25

A chord offset can be described as a distance between a point on the collar opening and a point on the plan view perpendicular to the collars opening

Question 26

Developing a pattern for a round reducing elbow uses __________ and _______ _____ development

Answer 26

Triangulation and parallel line development

Question 27

On a round reducing elbow when subtracting once chord offset from another you must always work from the __________ in

Answer 27

Outside

Question 28

When do the collars need to be developed on a round reducing offset ?

Answer 28

The collars need to be developed first

Question 29

On round reducing offsets the collars must be developed ______

Answer 29

First

Question 30

Round reducing y branches are typically found in _____ _______ systems

Answer 30

Dust collection

Question 31

How much of the pattern must be developed for an on Centre round reducing y branch ?

Answer 31

1/2 pattern

Question 32

How is the crotch mitre plan view developed ?

Answer 32

From the major and minor axis

Question 33

How is the ellipse developed in a round reducing y branch ?

Answer 33

With a minor and major axis

Question 34

Where are boots most commonly found ?

Answer 34

Residential duct systems

Question 35

Where are right angle boots commonly found ?

Answer 35

Above and below windows

Question 36

How many work lines are required for on Centre boots ?

Answer 36

One work line

Question 37

How many work lines are required for off Centre boots ?

Answer 37

Two work lines

Question 38

What is an advantage of top take offs ?

Answer 38

Top take offs allow branch lines and run within joists

Question 39

What view is used to triangulate end or right angle boots ?

Answer 39

Elevation view

Question 40

It is acceptable to use boot configurations when developing a _________

Answer 40

Wall stack

Question 41

The work line of a boot is found by measuring the centre of the ______ opening to the outside of the _____ opening

Answer 41

Round . Rectangular

Question 42

What types of pattern development are used on bull head tees ?

Answer 42

Line to line and triangulation

Question 43

What type of installations are bull head tees used in?

Answer 43

Blow pipe installations

Question 44

How many side of the triangle need to be triangulated in bull head tees ?

Answer 44

2 sides

Question 45

One foot of water equals ____ PSI

Answer 45

0.433 PSI