Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Third Year > Duct Construction > Flashcards

Duct Construction Flashcards

1
Q

Which one of these three things do you not need for pressure testing ?

Static
Leakage class
Leakage coiffecant
Velocity

A

Velocity does not matter for pressure testing

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is the best leakage class for pressure testing ?

A

Class a

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is the easiest joint to weld in light gauge sheetmetal ?

A

Standing seam
Flange

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What to do to veins when under a high pressure ?

A

Weld or solder

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What’s is the included angle of turning vanes on a 90 degree elbow ?

A

90 degrees

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What’s the smacna rules for screws when installing turning veins in duct ?

A

12” on center

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What does a two peice streamline used for ?

A

Goes around an obstruction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Where do we find specs for duct pressure classifications ?

A

Contract drawings

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

When no pressure classes are specified by the designer what pressure do we use ?

A

1” wc

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

For variable volume duct upstream of vav boxes what pressure do we use when designer does not give us a specific one ?

A

2” wc

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What are the 7 pressure ratings ?

A

10” wc
6”wc
4”wc
3”wc
2”wc
1”wc
1/2”wc

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What are the pressure ratings for medium pressure ?

A

6”wc
4”wc
3”wc

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What are the pressure ratings for low pressure ?

A

2” wc
1”wc
1/2” wc

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

2” acc 30x20 duct sized labeled on prong what size duct should we build ?

A

34x24

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What are the seal classes ?

A

A b and c a is the best c is the worst

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What percent is aluminum thinker than galvanized iron ?

A

44%

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

How many inches of water colum are residents duct systems usually ?

A

1/2” wc with low velocities less than 1000 fpm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What must be done before you can begin to design the ductwork ?

A

Load calculations and overall type of distribution system

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What organization gives u answers on how to construct duct work ?

A

Smacna

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What are some types of transverse joints

A

Slip and drive
Tdc
Big end small end pipe

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What’s another name for transverse joints ?

A

Gerth joints

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What’s the gerth joint for spiral pipe ?

A

Beaded sleeve joint

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What’s the shelf life of sealants ?

A

Less than 6 months

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What is the minimum amount of screws that should be placed along a diameter of 14” or less and must be used uniform intervals of atkeast 15” along the circumference?

A

Minimum 3 screws

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

What weld can be used for all pressure classes ?

A

Butt welds

26
Q

What is the strongest weld on round ?

A

Butt weld

27
Q

What joint is used in round ducts over 60”in diameter to help retain circular shape ?

A

Flange joint

28
Q

What’s the maximum hanger spacing ?

A

8ft or 10ft intervals

29
Q

What may you require to do for hangers on wider ducts ?

A

Trapeze bar

30
Q

What may installing intermediate hangers prevent ?

A

Any portion of the duct from sagging

31
Q

What is the range of the ductwork static pressure classifications ?

A

1/2” to 10” wc

32
Q

The letters STD indicate standard (non-variable volume) air duct construction requirements?

True or false

A

True

33
Q

The letters STV indicate the standard construction classification for variable volume ducts ?

True or false

A

True

34
Q

Beaded sleeves that join transverse round ducts must be ?

A

At least the same gauge as duct and minimum 4” long

35
Q

By how many inches should round duct transverse joints that are beaded and crimped be slip into one another ?

A

1”

36
Q

What is most commonly used for round duct reinforcements ?

A

Angle rings

37
Q

SMACNA refers to the part of a fitting collar that slips into the large end of spiral pipe. What is this part called ?

A

Spigot

38
Q

All duct constructed for 1” wc and 1/2” wc pressure classes must meet which seal class ?

A

Class c

39
Q

Does aluminum duct meet the requirements for equivalent strength and rigidity as galvanized duct ?

A

No aluminum is two gauges heavier

40
Q

What can not be used in commercial when wc is 2” and 2400 feet per minute ?

A

Fibrous duct

41
Q

For industrial duct systems pressure can range from above or below how many “ of wc ?

A

30” wc

42
Q

For industrial what are the three characteristics of materials to be conveyed?

A

Abrasiveness
Concentration
Corrosives

43
Q

Duct Designers must apply construction standards that are appropriate to specific situations the types of material being used and duct system features. What are the features ?

A

Joint seams
Reinforcements
Duct support

44
Q

When selecting a transverse joint it must be coincidentally with the following as outlined by Smacna . What 4 things to consider ?

A

Static pressure class
Applicable sealing requirements
Materials involved
Duct support intervals

45
Q

Liquid sealants that have high percents of solvents (30% to 60%) may what ?

A

Shrink when drying

46
Q

What sealant has excellent adhesion and elasticity and even some have fabric embedded in them ?

A

Mastics

47
Q

What sealant is usually used for fillets grooves and flanges ?

A

Mastics

48
Q

What is made from a friable material such as elastomer butyl that are made from open or closed cell rubber and are used for planted joints?

A

Gaskets

49
Q

Why is tape a questionable sealant

A

Tends to loose adhesion as it ages

50
Q

What should be done to all saddles ?

A

Seal them

51
Q

How do we attach angle rings to the duct wall ?

A

Screws
Rivets
Tack welds

52
Q

Rectangular longitudinal seams will vary according to what 3 things ?

A

Material thickness
Duct size
Local trade prefences

53
Q

Rectangular duct external reinforcements must be a maximum distances of _” from the ends and spaced at a maximum of _”

A

2”
12”

54
Q

What are the 4 types of rectangular duct external reinforcements ?

A

Angle
Hat section
Zee channel
U/ framing channel

55
Q

The duct hanging system is normally made up of three components what are they ?

A

The upper attachment
The hanger itself
Lower attachment

56
Q

Selecting the proper hanger system requires that you?

A

Transfer the load of ductwork’s weight to hanger system and secure it to building structure useing proper fasteners

57
Q

Most popular round transverse joint seam ?

A

Slip
Or lap type

58
Q

Maid advantage of high velocity duct systems ?

A

Thier smaller

59
Q

Is duct leakage more of a factor through an unconditioned space or a conditioned space ?

A

Unconditioned

60
Q

Unless otherwise stated a mitre elbow is based on Smacna standards and what else should be taken into consideration ?

A

Velocity

61
Q

Unless otherwise stated a mitre elbow is based on Smacna standards and what else should be taken into consideration ?

A

Velocity

62
Q

Compaion flange also know as van stone flange is used for round when ?

A

When round is over 60”

Third Year (10 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions