Triangulatuon ?

Question 1

What 2 ways can triangulation be described ?

Answer 1

1- finding the length of a hypotenuse useing ther vertical and horizontal legs of a right angle

2- developing the surfaces of fittings with surfaces that slant at diffrent angles

Question 2

What type of fittings can be developed with triangulation ?

Answer 2

Square to round /offsets
Top takeoffs
Right angle and end boots
Hoppers
Breaches
Ship ventilators
Twist
Rectangular duct transitions
Transitional duct elbow
dropCheck elbow
Y branches
transitonal offsets

Question 3

Lines perpendicular to the viewer line of vision are ? Can also be defined as dimension or line that is not distorted by the view ?

Answer 3

True length lines

Question 4

An object, construction or element line that is shorter than it Accutalky is because it is slanting towards or away from the viewer?

Answer 4

Foreshortened lines

Question 5

The horizontal leg is equal to the length of the foreshortened lines taken from the plan view. The vertical leg is equal to height of the fitting from elevation view. The length taken from the vertical leg to horizontal leg is known as the triangulated length. What is this describing ?

Answer 5

True length triangle

Question 6

A perpendicular line repressing the branch opening for an elbow or Y branch?

Answer 6

Face line

Question 7

What is vertical height ?

Answer 7

It’s a measurable length. The vertical height of the fitting may or may not include seams and allowances. When using the vertical height for triangulation all seams and allowances must be subtracted

Question 8

Define triangulation

Answer 8

Method used to develop patterns for irregular shapes and forms in which parallel or radial line cannot be used

Question 9

What is Pythagorean theorem?

Answer 9

An equation that recognizes the relationship between the sides of a right angle triangle

Question 10

Formula for Pythagorean theorem?

Answer 10

A2+B2=C2

Question 11

The hypotenuse is a side of what kind of triangle ?

Answer 11

Right angle triangle

Question 12

A foreshortened line is a line that appears shorter than it is ?
True or false

Answer 12

True

Question 13

What are true length triangles horizontal leg ?

Answer 13

A foreshortened dimension

Question 14

What is used to retro fit a new furnace to the existing plenum ?

Answer 14

Rectangular transitions

Question 15

Does the face line run 90 to a secondary y branch opening ?

Answer 15

No

Question 16

When determine the vertical height of a pattern what must be subtracted ?

Answer 16

Seams and allowances

Question 17

What are transitions and twists used for ?

Answer 17

Change duct sizes and positions in hvac system

Question 18

What must be used to develop center transitions ?

Answer 18

A plan view

Question 19

How would u label a transition plan view ?

Answer 19

Label top opening of transition 1-4 in clockwise direction label bottom abcd in clockwise direction as well

Question 20

Off center transition development steps ?

Answer 20

Plan view
Label all 4 sides
If labeled ba it’s outside if labeled ab its inside

Question 21

Would line 2b be a true length or foreshortened line ?

Answer 21

Foreshortened anytime a letter goes to a number

Question 22

How many sides of an off center transition can be developed without triangulation ?

Answer 22

2

Question 23

How many triangulated lines are in an off center transition?

Answer 23

2

Question 24

Does vertical height include collars ?

Answer 24

No

Question 25

What is the advantage of transitional elbows ?

Answer 25

Change direction dimensions and elevation all in one fitting . Try to keep both the throat and heel radius to a maximum

Question 26

What is a transitional y branches used for ?

Answer 26

Split airflow in 2 directions while changing size of duct as well

Question 27

Cheek patterns for transitional y branches are developed from what view ?

Answer 27

Elevation

Question 28

What line do u use to swing the heel arc on transitonal cheek for y branches ?

Answer 28

Face line

Question 29

When is an ogee offset used?

Answer 29

When the offset would be to great for a straight side offset

Question 30

Where can rectangular to round fittings be found ?

Answer 30

Dust collection fittings Roof jacks Rectangular to round offset fittings Rectangular to round 90s Garbage chutes

Question 31

When is the method of triangulation used?

Answer 31

When they cannot be developed from the plan view

Question 32

What is the work line equal to ?

Answer 32

1/2 the depth of fitting

Question 33

What are the diffrent types of boots ?

Answer 33

Right angle boots End boots Top takeoffs U boots

Question 34

What kind of hvac systems are boots normally found in ?

Answer 34

Residential

Question 35

Where are boots commonly found ?

Answer 35

By windows

Question 36

How many work lines are needed for on center boots ?

Answer 36

1

Question 37

How many work lines are needed for off center boots ?

Answer 37

2

Question 38

Top take offs allow branch lines to run where ?

Answer 38

Within the joists

Question 39

When triangulating boots what kind of view is used ?

Answer 39

Elevation

Question 40

A 1/2 pattern is needed when developing a pattern for off center right angle boots ? True or false

Answer 40

False

Question 41

It is acceptable to use boot configuration when installing a wall stack ? True or false ?

Answer 41

True

Question 42

What portion of a square to round on center do u need to develop it ?

Answer 42

1/4

Question 43

Do the distances around the opening of a square to round need to be triangulated ?

Answer 43

No

Question 44

When labeling a square to round where is the best place to start ?

Answer 44

Seam

Question 45

Are both plan and elevation views needed to develop a square to round ?

Answer 45

No

Question 46

Are the steps for laying out an off center square to round the same as an on center one ?

Answer 46

Yes

Question 47

What does vh on the right angle triangle refuse to ?

Answer 47

The length of fitting

Question 48

The horizontal leg on the right angle triangle is used for what?

Answer 48

Triangulating letters to numbers

Question 49

Are 12 equal spaces always used to divide the round opening ?

Answer 49

No

Question 50

What are commercial side take offs made out of compared to residential stos?

Answer 50

A heavier gauge

Question 51

What are round reducing y branches used for ?

Answer 51

Dust collection Commercial or industrial air handling

Question 52

When swinging from the middle crotch point for round y branches what is it called ?

Answer 52

Major axis

Question 53

What is the divided portion of the major axis called ?

Answer 53

Minor axis

Question 54

What work line does 2 and 3 go on for round y Branches ?

Answer 54

The small branch opening

Question 55

What is chord offset ?

Answer 55

Subtracting the small opening divided section from the large opening dived sections

Question 56

Where is point 10,12 and 14 located on round y branches?

Answer 56

The center seam line

Question 57

A round y branche consists of a primary opening and 2 what ?

Answer 57

Secondary openings

Question 58

Do we use a chord offset on round reducing y branches ? True or false ?

Answer 58

True

Question 59

The crotch mitre plan view is developed from what ?

Answer 59

Major and minor axis

Question 60

What is developed with the major and minor axis ?

Answer 60

Ellipse

Question 61

What two types of pattern development are used for a bull head tee?

Answer 61

Line to line and triangulation

Question 62

Where are bull head tees coming found ?

Answer 62

Blow pipe installations

Question 63

How many sides of the base triangle for a bull head tee needs to be triangulated ?

Answer 63

2

Question 64

When is it necessary to have a plan view for a bull head tee ?

Answer 64

Never

Question 65

What can the design of a bull head tee affect ?

Answer 65

Static pressure and friction loss

Question 66

What is a chord offset ?

Answer 66

A distance between a point on collar opening and a point on the plan view perpendicular to the collar openings

Question 67

When developing a round reducing elbow what type of pattern development is used ?

Answer 67

Parallel line and triangulation

Question 68

How many diffrent types of fittings are used to develop one round reducing elbow ?

Answer 68

2

Question 69

When subtracting one chord offset from another you must ?

Answer 69

Outside in

Question 70

Do collar patterns need to be developed first before u can develop body of a round reducing elbow ?

Answer 70

Yes