Gasfitting Theory Period 2 (CND) Flashcards
(152 cards)
1
Q
True or False: Piping or tubing may be supported by any larger pipe in the system?
A
False; Clause 6.8.3.
2
Q
Threaded schedule 40 steel piping maybe used for pressures not exceeding _______ psi.
A
125psi; Clause 6.2.3.
3
Q
Every hose and hose fitting shall have a minimum pressure rating of _____ psi.
A
350psi; Clause 6.2.9
4
Q
True or False: Natural rubber maybe used as a gasket material?
A
False; Clause 6.9.7
5
Q
True or False: A defective section of gas piping or tubing maybe repaired by a qualified gasfitter?
A
False; Clause 6.14.1
6
Q
A hose maybe used to connect an unvented appliance when it is______________.
A
Mobile or requires isolation from vibration;; Clause 6.20.2
7
Q
A corrugated metal connector shall not exceed 2’ in length when connecting a _____________.
A
suspended appliance or a decorative appliance.; Clause 6.21.3 (b)(c)
8
Q
Plastic piping shall only be used for _______________.
A
Outdoor or underground service; Clause 6.2.16
9
Q
True or False: Nesting of bushings is permitted on low-pressure gas piping.
A
False; Clause 6.14.2
10
Q
True or False: A girder, beam or joist maybe cut for the installation of piping.
A
True - Not so as to weaken it beyond its required purpose.; Clause 6.8.4
11
Q
Tubing run inside hollow walls within 1.75” of the surface shall b protected by?
A
NO. 16 GSG (1.59mm) Plates or Sleeves; Clause 6.16.4
12
Q
List 5 items a corrugated metal connector maybe used to connect. And shall be a maximum length of ?
A
Range, Refrigerator, Clothes dryer, Built-in counter or suspended or decorative appliances, or A room heater. And shall be a maximum length of 6ft.
13
Q
Type L or G copper tubing maybe used underground when it has been __________________.
A
Coated with extruded PVC or Polyethylene resin at the time of manufacture.; Clause 6.2.7
14
Q
A branch line must be the same diameter as the supply piping when it ?
A
Supplies an unknown future connection; Clause 6.10
15
Q
Gas piping, tubing and fittings may not be reused unless they were used on?
A
Gas before and are in as good as new condition. Clause 6.1.2
16
Q
A 2” NPS horizontal gas line must be supported every?
A
10ft; Table 6.1
17
Q
A piping outlet that it not connected to an appliance shall be terminated by means of ?
A
A plugged/capped valve,
A cap or plug compatible with the pipe or tubing employed.; Clause 6.12.1
18
Q
Underground tubing systems shall be joined be the means of?
A
Brazing (1000*F) approved mechanical compressing fittings or Approved flare fittings.; Clause 6.15.3
19
Q
A dirt pocket shall be installed on the ?
A
Final drop serving an appliance other than a range, a clothes dryer.
20
Q
A residential tubing system shall be identified at ?
A
6 foot intervals; Clause 6.17.3
21
Q
True or False: The use of left and right handed couplings is not permitted on a gas piping system.
A
True; Clause 6.14.3
22
Q
Piping or tubing shall be painted or coated when?
A
Outdoor piping, indoor piping or tubing systems are exposed to corrosive atmospheres.; Clause 6.16.1
23
Q
Piping or tubing shall be located at least _____ below a commercial driveway or parking lot.
A
24”; Clause 6.15.4
24
Q
For permanent installation, a hose shall not exceed _____ in length.
A
10 feet; Clause 6.20.3
25
The unthreaded portion of a piping outlet shall extend _____ through a ceiling or wall and ______ through a floor.
1" through a ceiling or wall and 2" through a floor. Clause 6.12.2
26
Piping or tubing extending from one building to another shall have a shutoff valve located at the?
exit of the first building and at the point of entry to the second building. Clause 6.18.8
27
A swing joint may not be installed in a ?
Concealed location. Clause 6.14.4
28
A construction heater shall be connected by a hose not less than _____ and no more than _____ in length.
15' and no more than 75'.; Clause 6.20.1
29
A bushing maybe used to reduce one pipe size when made of?
Steel; Clause 6.9.10(a)
30
True or False: A vented appliance maybe connected by a hose.
False; Clause 6.20.1
31
A drip pocket shall be provided where?
Condensate may collect. Clause 6.13.5
32
Where a commercial appliance maybe affected by vibration a _______ maybe used.
Hose connection may be used. Clause 6.20.2
33
Tubing laid on a rooftop shall be supported continuously with?
Treated wood and planks. Clause 6.26.2
34
The volume of gas required for each appliance shall be determine from _______________ and/or the manufacturer's specifications.
Appliance rating plate; Clause 6.4.2
35
Finished piping and appliance connections shall be checked under ___________ pressure with either a ___________ or a __________.
Normal Operating pressure with either Soap Solution or a Leak Detection Device. Clause 6.22.3(e)
36
An addition to an existing gas line is not subject to Table 6.3 when it is?
Less than 20' long or is a welded tie in. Clause 6.22.4(a)(b)
37
When a piping system is purged outdoors, the purge point must not terminate closer than?
10 feet from a building or air intake. Clause 6.23.7(a)
38
The maximum range of a test gauge shall exceed the test pressure by at least ____ but not greater than ____.
at least 15% but not greater than 300%. Clause 6.22.2(b)
39
A 2" NPS welded gas line shall be tested to a pressure of ____ psig or _____ times maximum operating pressure for ____ minutes.
50 psig, 1.5 times, 180 minutes. Table 6.3
40
A gas line operating at 10" w.c. shall be designed to prevent the loss of no more than ?
1" water column .
41
A purge line shall be no larger than _______ NPS for purging a line up to 4" NPS water column.
1/2" diameter.
42
True or False: Underground piping maybe covered 24 hours before being tested?
False
43
Pressure and duration of tests shall be in accordance with?
Table 6.3
44
After an appliance is connected and before the gas is turned on a, check shall be made to ensure that?
No openings permit the escape of gas, etc. Clause 6.22.3(a)(b)(c)(d)(e)
45
All factory-wrapped or coated piping shall be tested to a minimum of ?
100 psi.
46
A test gauge shall have a minimum diameter of?
3"
47
A gas line 4" NPS or larger that has been tested with air must be purged with ________ or ________ and then purged with ______.
Carbon dioxide or Nitrogen and then purged with Gas.
48
List 3 appliances that are not to be connected to a venting system.
```
Gas ranges,
Gas clothes dryers,
Portable gas-burners appliances,
Direct vent appliances,
Gas lights,
Any appliance approved for use without a vent.
```
49
A vent complying with ULC Standard CAN/ULC-S605 and consisting entirely of factory made parts, each designed to be assembled with the other without requiring field fabrication, and intended for venting gas appliances. these are constructed of a galvanized steel outer casing with an inner lining of aluminum separated by an air space (1/2" nominal). The maximum internal temperature is not exceed 470*F (243*C).
Type B Vent
50
A vent complying with ULC Standard CAN/ULC-S605 and consisting of factory made parts, each designed to be assembled with the other without requiring field fabrication, and intended for venting only wall furnaces for use with such type of vent. It is constructed of a galvanized steel outer casing with an inner lining of aluminum separated by an air space (1/2" nominal). The maximum internal temperature is not exceed 470*F (243*C). This vent is oval in shape.
Type BW vent
51
A vent complying with ULC Standard CAN/ULC-S609 and consisting of factory made parts, each designed to be assembled with the other without requiring field fabrication.It is constructed of a galvanized steel outer casing with an inner lining of stainless steel separated by an air space (1/2" nominal). The maximum internal temperature is not exceed 550*F (288*C).
Type L vent
52
What is the operating principle for a natural draft venting system?
Convection
53
What is the operating principle for an induced draft venting system?
Convection
54
Name the most common type of vent used for natural draft residential gas appliances?
Type B
55
What is the minimum allowable size (area) for Type B vent?
Equal to a 3" diameter pipe. Clause 8.13.3
56
What is the minimum internal dimension of a type BW vent?
2" (50mm) Clause 8.13.3
57
What is the minimum effective vent height for a Type B vent?
5 feet (1.5m); Clause 8.14.6
58
What shape may a gas vent be?
Any shape
59
True or False: All gas vents must terminate to the outdoors?
True
60
What is the minimum height of a gas vent termination above a flat roof?
2 feet (600mm); Clause 8.14.5
61
What is the minimum height of a gas vent termination above a sloped roof?
2 feet (600mm); Clause 8.14.5
62
What are the minimum installation height requirements for Type BW vent?
12 feet (3.6m) above the base of the wall furnace to the termination or changes of direction.
63
Masonry chimneys maybe used for gas-fired appliances without alteration if they are in good condition and have an?
Liner; Clause 8.12.8
64
What measurement must the chimney termination above a sloped roof be?
3 feet (900mm); Clause 8.14.4
65
What measurement must the chimney termination above a flat roof be?
3 feet (900mm); Clause 8.14.4
66
What is the minimum size of a chimney?
Area equal to 12 square inches or 4-inch diameter; Table C5, C6, C7, and C8
67
What code must the construction of a field-built chimney comply with?
Alberta Building Code
68
The basic function of a gas regulator?
To reduce and maintain a desired set point pressure while compensating for changes in downstream demand.
69
List the main parts of a self-operation low-pressure gas regulator?
Orifice, Diaphragm, and Spring
70
The outlet pressure of most residential regulators are set by adjusting the tension on a ?
Spring loading element.
71
Most pressure adjusting screws on regulators are protected from dust and tampering by a ?
Dust cap.
72
What is the function of a diaphragm in a pressure regulator?
To measure the outlet pressure and make corrective adjustments by opening or closing a valve disc at the restricting element.
73
The function of a vent on a regulator is to maintain ____________ above a diaphragm and a ___________________________.
Atmospheric pressure above a diaphragm and a Pathway of least restriction for gases to escape to a safe location.
74
A ruptured diaphragm is a gas regulator will allow the gas to ?
Constantly discharge from the vent opening.
75
What effect would a ruptured diaphragm have on the outlet pressure of a regulator?
It could make the regulator operate sluggish and create a slight overpressure situation on the downstream system.
76
Name the part of a regulator that determines the maximum capacity of gas that can pass through the regulator?
Orifice.
77
A device that can be used to control the movement of air through the vent of a regulator is a ?
Surge arrestor or vent-limiting device.
78
The vent on a regulator is protected from the entry of insects by a ?
Screened Opening.
79
2 devices that maybe used to control excessive outlet pressure in a gas regulator are an ________ valve or a ________ device.
Internal relief valve or a Line relief device.
80
The direction of flow through a regulator can be determined by finding the ___________________ on the body of the regulator.
Directional arrow or the word inlet.
81
Regulators should be installed s that they are protected from adverse conditions such as ?
Rain, excessive cold and ice.
82
It is recommended that regulators be installed in the __________ plane and that vents and vent-limiting devices be installed in the _______ plane.
Horizontal, Vertical
83
The 2 main considerations when selecting a regulator are ?
Volume of gas required through the regulator,
| and Downstream pressure.
84
Most domestic locally installed propane systems regulate delivery pressure in ?
2 stages.
85
The main considerations when installing regulators?
Install in the correct flow direction,
| Keep vent opening down
86
Natural gas appliance regulators for residential applications are usually set at ?
3.5" water column
87
The first stage propane regulator is usually located at the ___________ while the second stage regulator is usually located at the _____________.
```
Propane tank (attached),
Exterior of the building (attached to the wall)
```
88
Regulators installed inside a building are usually vented to the ?
Outdoors.
89
A first stage pressure regulator is recommended to be set at a maximum pressure of __________ and the second stage regulator pressure is generally set at _________.
10psig (70kpa) and 11" (275mm) water column
90
Explain one of the main problems that can occur with regulators exposed to low temperature or extremely high draws of gas.
Freeze-up low ambient temperatures may cause internal freeze up while high gas draws may cause external freeze up.
91
A system regulator, excluding a residential 2 psig (14kpa) regulator with a leak-limiting device, shall have?
A manual shut off valve installed upstream and An internal or line relief device vented to the outdoors.
92
The vent from an appliance pressure regulator having a diaphragm larger than _____ shall not be restricted.
6"
93
The 2 basic functions of a gas orifice are to?
Regulate the volume, and The velocity of the gas.
94
How is altitude affect the input rating of an appliance?
As altitude increases, atmospheric pressure decreases.
95
Low altitude is considered to be?
0 to 2000 feet (0 to 600m) above sea level.
96
High altitude rating is considered to be?
2000 to 4500 feet (600m to 1350m) above sea level.
97
The recommended practice for de-rating gas appliances installed above high altitude?
The appliance is de-rated an additional 4% per 1000 feet (300m) above 4500 feet (1350m) elevation.
98
The method used to check the firing of a gas appliance is?
Clock the meter.
99
The formula used to clock the gas meter is?
3600 x Size of Dial / Number of seconds per revolution = Cubic feet of gas per hour.
100
The direction in which a gas orifice should be drilling is in ?
The direction of the gas flow.
101
The rationale for drilling a gas orifice in the prescribed direction is so that ?
Any burrs that form can quickly and easily be removed with a file.
102
The recommended drill size to be used when drilling a gas orifice by hand is ?
2 sizes smaller than the recommended size fro the tables.
103
3 main designs of pilot burners?
Non-aerated, Aerated and Post-aerated.
104
What is the primary function of a pilot?
To effectively ignite the main burner.
105
What is the secondary function of some pilots?
Activating a flame failure device.
106
What is another term used to describe a aerated pilot?
Bunsen or Linting.
107
What is another term used to describe a non-aerated pilot?
Non-Bunsen or Non-linting.
108
A post-aerated pilot utilizes primary air and secondary air, but has no?
Mixing tube .
109
A pilot flame that is supervised by a flame failure device (Thermocouple)
Proved Pilot.
110
A pilot that burns constantly whether the main burner if fired or not.
Standing pilot.
111
A pilot that constantly burns at a low turndown, but is automatically increased at the call for heat for proper ignition.
Expanding pilot.
112
A pilot that is automatically ignited at the call for heat, ignites the main burner and remains on throughout the main burner cycle.
Intermittent pilot.
113
A pilot that is automatically ignited at the call for heat, ignited the main burner and is extinguished once the main burner is proven lit.
Interrupted pilot.
114
What is the fixed element that controls the amount of gas that a pilot will burn?
The Orifice
115
Name the adjustable component that controls the amount of gas the pilot will burn?
A needle valve, or on large appliances a pilot regulator.
116
What is the most common problem associated with a pilot that produces an orange flame?
Dirt, dust and other impurities in the air used for combustion .
117
The 2 types of hook-ups used for safety devices are _____ hookup and ______.
Safe hookups and 100% safe hookups.
118
What is the recommended distance from the ends for bending a thermocouple?
The rule is 1".
119
What is the recommended electromagnetic device used as a load in a safety circuit usually called?
Power Unit.
120
What is the recommended output range for the closed-circuit test on a thermocouple?
8-17 mV (Millivolts)
121
What is the recommended output range for the open-circuit test on a thermocouple?
17 to 32 millivolts (mV0
122
What is the solution for a failed turn-down test?
Relocate the pilot burner.
123
Name the type of electrical current generated by a thermoelectric device?
Direct Current (DC)
124
What does the electrical output of a thermoelectric device depend on?
The amount of heat applied to the thermocouple and the difference in temperature between the hot and cold junction.
125
The pilot flame should cover the tip of the thermocouple by ?
3/8" to 1/2"
126
2 functions a thermopile can perform?
Operate the safety system (Power unit) and Operate the main burner gas valve (Operating gas valve).
127
A thermopile is a number of thermocouples connected in ?
Series.
128
If the wiring on a thermopile circuit exceeds 80 feet, a ______ system should be considered.
24-volt system.
129
What is the thermopile test called that is similar to the drop-out test performed on thermocouples
Pull-in voltage test.
130
What test is used on a thermopile system to test proper ignition of the main burners at a low pilot flame condition?
An effective ignition
131
What is the principle of motivation of the gases in the natural draft venting system?
Hot gases rise (Convection)
132
2 basic types of draft control devices used on gas-fired appliances?
Draft hoods and Double acting draft regulators (Barometric damper)
133
What is the basic design difference between a draft hood and a barometric draft control?
The draft hood has no moving parts (Fixed Opening)
134
Alteration of draft control devices by the gasfitter is ?
Prohibited. (Clause 8.23.3)
135
3 methods used to check draft condition in a gas venting system?
Match Test,
Smoke test,
Gauge test.
136
3 domestic gas appliances that do not require a draft hood?
Incinerators,
Dual oven combination ranges,
Direct vent appliances. (Clause 8.23.1)
137
3 locations where draft hoods cannot be installed?
False ceiling space,
In a different room to that of the appliance,
In any manner that could permit a differential air pressure between the draft hood relief opening and the combustion air supply. (Clause 8.23.6)
138
3 types of materials that may be used for vent connectors?
Galvanized steel,
Aluminum,
Type B Vent.
139
Appliances should be installed as close as is practical to the vertical vent so that the vent connector is as?
Short and direct as possible.
140
What is the minimum wall thickness of a GSG vent connector without dilution air?
24 galvanized sheet gauge (GSG) (Clause 8.18.1)
141
What is the minimum wall thickness for the vent connector on a gas fired incinerator?
20 GSG (Clause 8.18.2)
142
The maximum temperature of combustible surfaces shall not exceed?
194*F (90*C) (Clause 8.18.12 (b))
143
What is the general clearance requirement for vent connectors made of other than type B material?
6" (Table 8.6)
144
What is the general clearance requirement for vent connectors made of type B material?
1" (Table 8.6)
145
With an office adjustment and you are drilling at whole always drill
2 sizes smaller then desired.
T q
146
Most commonly used orifice would be ?
Fixed orifice. 19 degrees. Type two
147
B vent mun diameter inside natural draft is ?
3inch
148
B vent approx temp
470degreef
149
L vent temp is ?
290c or 550 degrees f
150
The min length for a vent connector is ?
1foot
151
A vertical vent above a draft hood is minimum ____feet
5
152
Min high of vent from bottom of heater to outlet is ??
12 feet
