Chapter 7 (7.4.1 - 7.15.2)

Question 1

(7.4.1) Pressure Reduction. Where pressure reduction is required in branch connections for compliance with 5.5.1, such reduction shall take place ___(A)___ or ___(B)___

Answer 1

(A) either inside the chase or (B) immediately adjacent to the outside wall of the chase.

Question 2

(7.4.1) Pressure Reduction. Regulator venting and downstream overpressure protection shall comply with 5.8.55.8.6 and section 5.9. The regulator shall be accessible for service and repair and vented in accordance with one of the following.

(1) Where the fuel gas is lighter than air, regulators equipped with a vent limiting means shall be permitted to be ___(A)___. Regulators not equipped with a vent limiting means shall be permitted to be vented either directly to the outdoors or to a point ___(B)___.

(2) Where the fuel gas is heavier than air, the regulator vent shall be ___(C)___.

Answer 2

(A) vented into the chase
(B) within the top 1 foot of the chase
(C) vented only directly to the outdoors.

Question 3

(7.4.3) Ventilation. A chase shall be ___(A)___. The opening(s) shall have a maximum free area (in square inches) equal to the product of one-half of the maximum pressure in the piping (in pounds per square inch) times the largest nominal diameter of that piping (in inches), or the cross-sectional area of the chase, whichever is smaller. Where more than one fuel gas piping system is present, ___(B)___ and the largest area used.

Answer 3

(A) Ventilated to the outdoors and only at the top.
(B) the free area of both systems shall be calculated

Question 4

(7.5) Gas Pipe Turns. Changes in direction of gas pipe shall be made by the use of ______.

Answer 4

fittings, factory bends, or field bends.

Question 5

(7.5.1) Metallic Pipe. Metallic pipe bends shall comply with the following
(1) Bends shall be made only with bending tools and procedures intended for that purpose.
(2) All bends shall be smooth and free from buckling, cracks, or other evidence of mechanical damage.
(3) The longitudinal weld of the pipe shall be near the neutral axis of the bend.
(4) Pipe shall not be bent at an arc of more than ___(A)___
(5) The inside radius of the bend shall not be less than ___(B)___

Answer 5

(A) 90 degrees
(B) 6 times the outside diameter of the pipe.

Question 6

(7.5.2) Plastic pipe. Plastic pipe bends shall comply with the following: The radius of the inner curve of such bends shall be no less than ______.

Answer 6

25 times the inside diameter of the pipe.

Question 7

(7.6.1) Provide drips where Necessary. For other than dry gas conditions, a drip shall be provided at any point in the line of pipe where condensate could collect. Where required by the authority having jurisdiction or the serving gas supplier, a drip shall also be provided at the outlet of the meter. The drip shall be installed so as to _______ before it runs back into the meter.

Answer 7

constitute a trap wherein an accumulation of condensate shuts off the flow of gas.

Question 8

(7.6.2) Location of Drips. All drips shall be installed only in such locations the they are ___(A)___ to permit cleaning or emptying. A drip shall not be located where the condensate is ___(B)___.

Answer 8

(A) Readily accessible
(B) likely to freeze

Question 9

(7.6.3) Sediment Traps. The installation of sediment traps shall be in accordance with 9.6.7. Where a sediment trap is not incorporated as a part of the appliance, a sediment trap shall be installed ______. The sediment trap shall be either a tee fitting with a capped nipple in the bottom outlet as illustrated in figure 9.6.7 or other device recognized as an effective sediment trap. Illuminating appliances, ranges, clothes dryers, decorative appliances for installation in vented fireplaces, gas fireplaces, and outdoor grills shall not be required to be so equipped.

Answer 9

downstream of the appliance shutoff valve as close to the inlet of the appliance as practical.

Question 10

(7.7.1.2) Can outlets be located behind doors?

Answer 10

No

Question 11

(7.7.1.4) The unthreaded portion of gas piping outlets shall extend ______ or indoor or outdoor walls.

Answer 11

not less than 1 inch through finished ceilings

Question 12

(7.7.1.5) The unthreaded portion of gas piping outlets shall extend ______ above the surface of floors or outdoor patios or slabs.

Answer 12

not less than 2 inches

Question 13

(7.7.2.1) Each outlet, including a valve, shall be closed gastight with a ___(A)___>
When an appliance or equipment is disconnected from an outlet and the outlet is not to be used again immediately, it shall be capped or plugged gastight.

Exception 1: ___(B)___ installed in accordance with 9.6.2(1) shall be permitted.

Exception 2: The use of a ___(C)___ with integral shutoff or listed gas convenience outlet shall be permitted.

Answer 13

(A)Threaded cap or plug immediately after installation and shall be left closed until the equipment or appliance is connected thereto.
(B) Laboratory appliances
(C) listed quick disconnect valve

Question 14

(7.8) Branch Pipe Connection. When a branch outlet is placed on a main supply line before it is known what size pipe will be connected to it, the outlet shall be ______

Answer 14

of the same size as the line that supplies it.

Question 15

(7.9.2.1) Accessibility of Gas Valves. Main gas shutoff valves controlling several gas piping systems shall be ___(A)___ for operation and installed so as to be ___(B)___. They shall be marked ___(C)___ or other permanent means attached by the installing agency so that the gas piping systems supplied through them can be readily identified.

Answer 15

(A) readily accessible
(B) protected from physical damage
(C) with a metal tag

Question 16

(7.9.2.2) Shutoff Valves for Multiple house lines. What is the minimum amount of shutoff valves needed for multiple units in one building.

Answer 16

an individual shut-off shall be provided for each apartment or tenant.

Question 17

(7.9.2.3) Emergency Shutoff Valves. An exterior shutoff valve to permit turning off the gas supply ______ as such and their locations posted as required by the authority having jurisdiction.

Answer 17

to each building shall be provided. The emergency shutoff valves shall be plainly marked

Question 18

(7.9.2.4) Shutoff Valve for Laboratories. Each laboratory space containing two or more gas outlets installed on tables, benches, or in hoods in educational, research, commercial, and industrial occupancies shall have ___(A)___ through which all such gas outlets are supplied. The shutoff valve shall be accessible, located ___(B)___

Answer 18

(A) a single shutoff valve
(B) within the laboratory or adjacent to the laboratory’s egress door, and identified.

Question 19

(7.10) Prohibited Devices. No device shall be placed inside the gas piping or fittings that ______ except where proper allowance in the piping system design has been made for such device and where approved by the authority having jurisdiction.

Answer 19

reduces the cross-sectional area of the pipe or otherwise obstructs the free flow of gas.

Question 20

(7.12.5.3) Air Intakes. Air intakes for gas mixing machines using compressors or blowers shall be ______.

Answer 20

taken from outdoors whenever practical.

Question 21

(7.12.6) Use of Automatic Firechecks, Safety Blowouts, or Backfire preventers. Automatic firechecks, safety blowouts, or backfire preventers shall be provided in piping systems distributing flammable air-gas mixtures from gas-mixing machines to ______.

Answer 21

to protect the piping and machines in the event of flashback.

Question 22

(7.13.1) Pipe and tubing other than CSST. Each aboveground portion of a gas piping system, other than CSST, that is likely to become energized shall be electrically continuous and bonded to an effective ground-fault current path. Gas piping, other than CSST, shall be considered to be ______.

Answer 22

bonded when it is connected to an appliance that is connected to the appliance grounding conductor of the circuit supplying that appliance.

Question 23

(7.13.3) Prohibited Use. Gas piping shall not be used as _____.

Answer 23

a grounding conductor or electrode.

Question 24

(7.15.2) Any essential safety control depending on electric current as the operating medium shall be of the type that ______.

Answer 24

shuts off (fail safe) the flow of gas in the event of current failure.