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Plumbing Year 4 > GAS RS & TQ > Flashcards

GAS RS & TQ Flashcards

1
Q

how far can a pool heater be from the property line?

A

18”

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2
Q

how far must a direct vent be from a regulator vent?

A

3’

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3
Q

how many supports does a horizontal propane tank need

A
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4
Q

Max pressure in a family dwelling?

A

2psig

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5
Q

max propane pressure in a commercial building

A

20Psig

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6
Q

What type of material for a gasket

A

neoprene

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7
Q

Joining method for tubing underground?

A

Brazed, flare or mechanical
approved compressio

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8
Q

what is the max distance of Metal flex conn for decorative appliance?

A

2’

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9
Q

standard vent termination for gas above roof?

A

2’

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10
Q

What type of pipe is not allowed on gas:

A

cast iron

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11
Q

buried plastic pipe needs what:

A

tracer wire

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12
Q

min bury depth of gas line?

A

15” unless its a comm drive way then its 24”

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13
Q

Higher flammability of propane:

A

9.6%

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14
Q

when does the high limit operate?

A

an temp rise

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15
Q

min. service clearance?

min clearance of b vent?

min clearance c vent?

A

SER = 24”
B = 1”
C= 6”

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16
Q

How does the relief vent of a propane cylinder have to be connected?

A

in contact with vapour space and lose cap fitting

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17
Q

Know distances for vaporizer

A
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18
Q

plastic piping is allowed on liquid propane systems?

T or F

A

F

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19
Q

How far should a rooftop unit be from the edge?

A

6’

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20
Q

What is the minimum length of a dirt pocket:

A

3” but matches the diameter of piping

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21
Q

what must piping have in a corrosive environment?

A

a coating

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22
Q

if piping is less then 1/2” what must it be made of?

A

Schedule 80 pipe

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23
Q

what is the smallest pipe diameter that can be concealed?

A

1/2”

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24
Q

what is regulator freeze up caused by?

A

high demand

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25
Q

If snare flame at a regulator vent limiting orifice:

A

pin hole in
diaphragm?

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26
Q

incomplete combustion creates what harmful products

A

aldehydes

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27
Q

why do you drill a orifice two dms size smaller?

A

because can drill
steady enough to have a prefect hole

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28
Q

what type of current is use on a rectification signal?

A

DC

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29
Q

Primary air

A

provides a percentage of the combustion air, but more
importantly it controls the amount of fuel that can be burned
efficiently.

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30
Q

Secondary air

A

increases combustion efficiency by causing the fuel to
completely burn. Atmospheric burners require secondary air, but power
burners do not; however, air leaking in at the access or cleanout doors
will allow some secondary air to enter the combustion chamber.

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31
Q

Excess air

40% of theoretical air

A

s supplied to the combustion zone, is air in excess of the
air which is theoretically needed for combustion. It is added to ensure
each molecule is surrounded by air. Tuning the burner will improve the
mixing of the fuel and air, thereby reducing the amount of excess air
required. If the excess air is dramatically increased beyond what is
actually needed, the result will be lowered flue gas temperatures,
leading to lower combustion efficiency.

32
Q

Dilution air

A

does not directly promote the combustion process but is
used to control the stack effect and to reduce the probability that the
moisture formed by the combustion of the fuel will condense in the
venting system. This will influence the amount of combustion air taken
in.

33
Q

Theoretical air

A

Input BTU/ Calorific Value = CFH Natural Gas

CFH Gas X Ratio (10, 24, 31) = Theoretical Air

34
Q

Excess air

A

40%

35
Q

The amount of air to completely burn twenty cubic feet of propane gas

A

25 Calorific Value X 20 CU ft = 500 Cu Ft

36
Q

how are Cylinders holding less then 300lbs. of propane filled?

A

by weight

37
Q

he first indication of poor combustion would be a?

A

yellow flame

38
Q

A thermocouple must be inserted ____ to _____ into the pilot flame

A

3/8” to 1/2”

39
Q

The highest combustion efficiency in an appliance is obtained with:

A

ow stack
temperature and high CO2

40
Q

he most common pilot burner found in gas appliances is a:

A

target type

41
Q

The purpose of a draft hood is to

A

Allow the entry of dilution air, maintain a zero
overfire draft, dry the flue gases

42
Q

Ultimate C02 for natural gas is

A

12%

43
Q

Ultimate C02 for propane is

A

14%

44
Q

to correct a lazy flame you must

A

increase the primary air supply

45
Q

Hot water boiler service clearance (in front)

A

48” infront

46
Q

Counter flow furnace being installed on a combustible floor must have

A

a factory
supplied base tee

47
Q

domestic gas fired clothes dryer is not allowed to be installed where?

A

Bathroom

48
Q

Appliance draft hood can be installed and connected to:

A

B vent, BW vent, a chimney

49
Q

how are bw vent and b vent different

A

in shape

50
Q

How many gallons of propane will a cylinder with WC (Water Capacity) of 595
hold at maximum filling density

A

595 X .42 (Specific Density)/5.1 Lbs = 49
Gallons

51
Q

The minimum distance that 1000 USWG tank can be located from a concrete wall
is

A

10’

52
Q
A
53
Q

propane tank must be supported by no more the ______ supports

A

2

54
Q

Propane cylinders stored at a construction site must be stored ________ in a secure
area

A

outside

55
Q

he minimum clearance from combustibles for a single wall connector is _________ inches

A

6 inches

56
Q

Flame sensing range

A

1-10 microamps

57
Q

he recommended spark gap on an IPI pilot assembly is a _______ inch gap

A

1/8 inch

58
Q

A type BH vent would have a stack temp rating of about ______ deg F

A

125 deg F

59
Q

When a transformer in a system repeatly burns out what might be the issue

A

wrong VA rating on the transformer

60
Q

VA rating

A

VA Rating is Voltage X Amperage=VA (Watts)

61
Q

open circuit test ranges

A

Thermocouple using an open circuit test must be 17-32 mV

Thermopile using an open circuit test must be 500-750 mV

62
Q

HWT clearances

A

Residential Hot water tank min 2” from combustible materials
Other Hot water tanks min 6” Clearance
Service clearance of 24“
Direct vented requires 3’ from burner side

63
Q

Unit heaters clearances

A

8’ from floor unless protected
4’ from floor protected
Clearance from combustibles is 18 “

64
Q

furnace clearances

A

Above 1”
Sides and rear 6”
Front is 24”

65
Q

Boiler clearances

A

Top, sides, rear 18”
Front 48”

66
Q

Natural Gas “Stats”

A

chemical formula: CH4
CV: 1000
C.A.R.: 10:1
Spcific Grav g/L: 0.6/0.424
Flame range: 5-15%

67
Q

Propane Gas “Stats”

A

chemical formula: C3H8
CV.: 2500
C.A.R.: 24:1
Specific Grav G/L: 1.5/.51
Flame range: 2.3-9.5%

68
Q

Fluctuating flame is caused by:

A

plugged vent on regulator

69
Q

a noisy lifting flame is caused by:

A

too much air (adjust primary air shutter)

70
Q

what are the three types of orifices?

A

plug cap and adjustable

71
Q

Safe shut off means

A

pilot stays lit

72
Q

100% shut off means

A

all the gas is off

73
Q

OHMS law formula

A

E/IR

e voltage
i amperage
R resistance

74
Q

vent termination from a mechanical air intake is _____ feet

A

10

75
Q

How is the flame sensing current measured?

A

between spark and ground

76
Q
A

Plumbing Year 4 (28 decks)

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