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Plumbing Level 3 > E2: Install Gas Piping and Tubing Systems > Flashcards

E2: Install Gas Piping and Tubing Systems Flashcards

1
Q

What is included in a piping system?

A

pipe, tube, connector, hose or fitting used to carry fuel gas from supply –> appliance

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2
Q

What is required when jointing sealant is used?

A
  • Apply to male ends
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3
Q

How should T-tape be used?

A

Tape has to be stretched and applied in a clockwise direction
- have a 50% overlap
- Leave the first 2 started threads bare

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4
Q

How are steel pipe seized 2 1/2” and over connected?

A

With welded joints

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5
Q

What must threaded fittings be made of?

A

malleable iron or steel construction

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6
Q

Why can’t cast iron threaded fittings be used?

A

more susceptible to cracking

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7
Q

How are cast iron fittings differentiated from malleable fittings?

A

Cast iron hubs are larger (“heavier reinforced bead”)

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8
Q

All pipe thread have to be free of what?

A

burrs, scale and defects

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9
Q

Do all pipe ends have to be reamed?

A

Yes

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10
Q

How are press fittings designed?

A

If there are any un-pressed connections, it will leak past the internal sealing element (

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11
Q

What fittings are NOT approved for steel pipe?

A

-Fittings w/ running threads (thread protectors)
-Close nipples
- Street elbows
- Fittings w/ right or left hand threads

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12
Q

What kind of bushing is used when there is 1 pipe size change?

A

Forged steel bushing

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13
Q

What type of material is used when reducing to min 2 pipe sizes?

A

Malleable iron or steel

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14
Q

What is nesting mean?

A

using multiple bushings together

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15
Q

What type of fittings can be used with Copper pipe?

A

flared
brazed
press - connect

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16
Q

Can compression fittings be used with copper pipe?

A

If AHJ approves

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17
Q

What type of flare fittings has to be used?

A
  • use soft annealed copper
  • 45 degree type
  • does not come with nuts (have to purchase separately)
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18
Q

What are flared fittings made of? (BF)

A

Brass forged type

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19
Q

Can externally machined nuts be used?

A

No, they are not strong –> wall thickness decreased dt machining process

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20
Q

How are CSST tubing connected?

A

By using self-flaring brass fittings –> creates a metal to metal seal when tightened.

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21
Q

True or False: only manufactured certified fittings can be used with CSST pipe

A

True

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22
Q

Adapter fittings used for CSST pipe have what kind of threads?

A

standard NPT

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23
Q

What can be used in place of fusion fittings for PE pipe?

A

PE compression slab lock fittings

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24
Q

Manual shut offs are required where?

A

for each appliance / must be readily accessible

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25
Q

If a manifold is being used, where can shut off valves be placed?

A

at the manifold.
If AHJ approves

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26
Q

Where are manual shut offs installed?

A

upstream of any line pressure regulators that in the system or any underground section of pipe

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27
Q

What kind of turn must a manual shut off have?

A

A quarter

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28
Q

What type of valves can be used for shut offs?

A
  • ball
  • plug
  • eccentric type
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29
Q

Shut off valves can be used as long as they are rated for what?

A

for the pressure and temperature they are being used for

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30
Q

What is the most common shut off used?

A

ball valve

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31
Q

Where would you find a lubricated plug valve?

A

Utilities meter set

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32
Q

Where are eccentric style valves seen?

A

larger applications –> over 2” in size

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33
Q

What is a benefit of the offset half plug?

A

Creates less friction = lower operating torque needed for large valves

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34
Q

Quick disconnects has what kind of internal device?

A

shut off

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35
Q

What must be installed in addition to a quick disconnect shut off?

A

manual shut off valve installed upstream of quick -disconnect device

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36
Q

What is a gas convenience outlet?

A

It is a combined units w/ the quick disconnect + manual shut off supplied as a unit

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37
Q

What additional feat does a manually operated gas valve have?

A

a handle designed so that disconnection can be accomplished only when the gas valve is in the closed position

38
Q

Where can we see Dirt pockets?

A
  • inlet to an appliance regulator
  • at the base of a vertical drop to an appliance
39
Q

How does a dirt pocket work?

A
  • designed to capture dust before it enters the appliance
  • reduces the chance of clogged gas valves or orifices
40
Q

Drip pockets have to be provided where?

A

at all points in a piping system where condensation can collect
(ex: wide ranges or sudden temp changes)

41
Q

True or False: drip / dirt pocket names are used interchangeable.

A

True

42
Q

Why must piping or tubing be mounted, braced and supported?

A

To provide for expansion, contraction, jarring, vibration / settling = no wear or strain on the piping.

43
Q

What are the additional considerations for commercial or industrial roof tops?

A

pipe movement caused by thermal expansion / contraction

44
Q

How are thermal expansion / contraction supported?

A

through designed pipe bends, loops, offsets or expansion joints

45
Q

True or False: pipes have to be anchored at appropriate locations to control direction or expansion / contraction

A

True

46
Q

Can gas piping enter the building from underground?

A

No, it has to rise above grade before entry unless otherwise permitted by AHJ

47
Q

What must happen when gas lines pass through an exterior wall above ground?

A
  • must be sealed in a watertight / portion running through the wall sleeved or double wrapped w/ a waterproof wrap
48
Q

Joints or Fittings must be what before being covered up?

A

tested / inspected

49
Q

Where can’t gas pipes be installed?

A
  • stairwell (unless chase available)
  • chimney, dumbwaiter
  • heating or vent plenum, duct, shaft
  • cinders, ashes, corrosive materials
  • under a foundation wall
50
Q

What happens if gas pipe has to be installed in concrete?

A

it has to be laid in channels / encased in ventilated ducts so there are free air space around

51
Q

What are the rules for a vertical chase?

A
  • has to have an opening at the top / bottom
  • openings have to be 1” in diameter around the pipe
52
Q

Damaged pipe results in

A

reduced life expectancy
failure of the piping system

53
Q

What are 3 basic methods to protect pipes?

A

1) protective coatings
2) physical/ mechanical damage protection
3) cathodic protection

54
Q

Why is coating or wrapped gas piping not recommended?

A

due to exposure to sunlight / rain / snow = thermal expansion / contraction

55
Q

How can you avoid galvanic corrosion?

A

install pipe so that it is not in contact with dissimilar metals

56
Q

Why must piping be sleeved or double wrapped when running through masonry or concrete?

A

It is very corrosive

57
Q

When should striker plates be used?

A

When pipe is running through hollow walls

58
Q

How can piping be protected from vehicular traffic locations?

A

By posts or guard rails

59
Q

How should piping be supported that runs vertical out of the ground?

A

a sleeve to prevent free movement of the soil / covering w/o placing strain on the pipe

60
Q

How can gas lines be located underground?

A

by placing a yellow poly coated tracing wire (or something like it) or magnetic tape, buried alongside the pipeline

61
Q

Where should the tracer wire be placed exactly?

A

Laid within 6” of the plastic pipe, where its practical but is possible - directly above pipe

62
Q

Do we have to worry about the ends of the tracer wire?

A

yes, place them were they can be easily accessible so they can connect to electronic tracing equipment

63
Q

When do additional corrosion control measures come into play?

A

When steel gas pipe is buried.

64
Q

When does electrochemical corrosion occur?

A

When 2 dissimilar metals contact each other in a moisture - rich environment

65
Q

How does corrosion occur?

A

one metal becomes a cathode, the other metal becomes an anode (usually the pipe), which corrodes / develops a leak

66
Q

What are 3 methods of protecting underground pipe from corrosion

A

1) protective coatings
2) cathodic protection
3) electrical insulation

67
Q

How do protective coating protect pipe?

A

They insulate the pipe from the soil (aka the electrolyte)
- adheres tightly to soil
- can withstand soil stresses, tendency towards cracking

68
Q

What does high dielectric strength mean?

A

It’s a good electrical insulator

69
Q

What are the main coating used?

A

Yard - applied coal tar
Extruded PE

70
Q

Can the integrity of the pipe coating be tested?

A

yes

71
Q

What is Jeep or Holiday mean?

A

Areas on a pipe that are not protected?

72
Q

What is a Jeep meter?

A

Is an electronic testing unit
It finds imperfections / allows repairs prior to being buried

73
Q

What happens if 2 metals have a different electrical potential?

A

A current will flow between them

74
Q

How does current flow?

A

From active metals (metals with higher potential) to less active metals (metals w/ lower potential)

75
Q

What are 4 things necessary for galvanic corrosion to occur?

A

1) An anode
2) A cathode
3) An electrolyte
4) A conductive path

76
Q

True or False: It doesn’t matter if metals are close or far, a current will still flow.

A

True

77
Q

For galvanic corrosion to occur, there must be a complete electrical circuit, correct?

A

Yes

78
Q

True or False: the electrical current travels from cathode to anode.

A

False: travels from anode to cathode (A before C)

79
Q

What is the simplest method of protecting against galvanic corrosion?

A

Connect the protected metal to a sacrificial metal via insulated conductor
(sacrificial metal will act as the anode)

80
Q

What are 2 basic methods of cathodic protection?

A

1) Passive Galvanic anode system
2) Impressed Current System

81
Q

Anodes are made up of what?

A

Magnesium (Mg) –> Used in BC
Zinc (Zn)
Aluminum (Al)

82
Q

What does a sacrificial anode here consist of?

A

A bag containing either magnesium or zinc igot / other chemicals.
Is connected by a wire –> underground metal piping system

83
Q

How does the sacrificial anode function?

A

As a battery => induces a direct current on the piping system to slow corrosion

84
Q

What is the difference bn a Passive galvanic anode system and a impressed current system?

A

Passive - uses sacrificial anode
Impressed - uses shania twain (that don’t impress me much)
- also uses a DC electrical power source

85
Q

How is the direct current induced?

A

by means of a rectifier

86
Q

Where are Impressed current systems used?

A

along transmission pipelines
(less interference w/ other pipelines)

87
Q

In an Impressed Current System, what are the anodes here made of?

A

corrosion - resistant material used to disperse the electrical current
(graphite, silicone cast iron, lead- silver alloy, platinum, scrap steel)

88
Q

What kind of output does the DC rectifier have?

A

10 - 50 amps
50 volts

89
Q

What is the point of installing a dielectric fitting on the pipeline directly outside the building wall?

A

Prevents electrical contact bn underground piping (protected piping) + above ground / unprotective piping

90
Q

What is the common dielectric fitting used?

A

insulated union
insulated flange
insulated meter spud

91
Q

What should be added to piping systems to identify contents of any section of piping in a facility?

A

Pipe markers

92
Q

What colour are all flammable or oxidizing fluids or gas?

A

Yellow w/ black text

Plumbing Level 3 (26 decks)

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