Fuel Gas Code

Question 1

Sediment Traps are required in gas piping systems and must be located ______

Answer 1

After the appliance shutoff valve and as close as possible to the inlet of the equipment.
Pg. 76 Fuel Gas Code

Question 2

You have a 45,000 btu/hr hot water heater and a 60,000 btu/hr furnace installed inside a building. How many cubic feet of combustion air is required for these two appliances when using indoor air for combustion?

Answer 2

5,250cu.ft.
Pg. 17 Fuel Gas Code

50cu.ft. per 1000btu
50 x 45= 2250cu.ft.
50 x 60= 3000cu.ft.
2250 + 3000= 5250cu.ft.

Question 3

What is the maximum distance between supports for 1/2in semi rigid copper tubing when used as a gas line?

Answer 3

4ft.

Pg. 81 Fuel Gas Code

Question 4

You are running a gas vent from a space through a ventilated attic. The vent travels through the attic insulation. what is the clearance you are required to maintain with an insulation shield if the vent is connected to a Category 1 furnace and the vent is type B double-wall?

Answer 4

1in

Pg. 84 Fuel Gas Code

Question 5

A room inside a building has 100,000 btu/hr furnace and two 45,000 btu/hr water heaters installed that are taking combustion air from the space. How many cubic feet of air is needed for combustion air based on the standard method?

Answer 5

9500cu.ft.
Pg. 17 Fuel Gas Code

50cu.ft. per 1000btu
50 x 190= 9500

Question 6

A corrugated stainless-steel tubing gas network has a longest length of 90ft. How many cubic feet of natural gas can a branch line that is 20ft long EHD18 carry if the meter is less than 2psi, the design pressure drop is .5inwc, and the specific gravity is .60?

Answer 6

58cu.ft.

Pg. 45 Fuel Gas Code

Question 7

Your installation requires a clearance to combustible materials for a single-wall metal pipe vent connector of 12 inches along the side wall. You only have 6 inches. What is the least expensive form of protection code will accept to allow the installation to pass inspection with the 6in clearance?

Answer 7

1/2in insulation board over 1in glass fiber or mineral wool batts.
Pg. 24 Fuel Gas Code

Question 8

When installing plastic gas piping outside and underground, the tracer wire shall terminate _____.

Answer 8

Above grade at each end.

Pg. 73 Fuel Gas Code

Question 9

When installing sediment traps(drip legs) in gas piping, the length of the sediment trap shall be ______.

Answer 9

Any length.

Pg. 76-77 Fuel Gas Code

Question 10

Can single wall metal tee and wye fittings be used to connect appliances to a common gas vent made from type B-vent?

Answer 10

No

Pg. 97 Fuel Gas Code

Question 11

When 90 degree elbows are installed in gas vent installations, a reduction of _______% shall be applied to the vent table cavities in section 504.

Answer 11

10%

Pg. 97 Fuel Gas Code

Question 12

A structure has an 80,000btu/h furnace and a 65,000btu/h water heater in a basement that measures 30ft x 50ft and has 8ft ceilings. How many cubic feet of combustion air is needed for these appliances?

Answer 12

7250cu.ft.

80,000btu/h + 65,000btu/h = 145,000btu/h
Standard method 50cu.ft per 1000btu/h
50 x 145 = 7250cu.ft.

Question 13

Two appliances are connected to a single type-B vent system. One is an 80,000btu/h furnace with a 4in vent outlet and the other is a 45,000btu/h water heater with a 3in vent outlet. How does the code expect them to connect to the single vent pipe?

Answer 13

The smaller connector shall enter at the highest level consistent with the available headroom or clearance to combustible material.
Pg. 93 Fuel Gas Code

Question 14

A 24inx 24in stamped metal grill is used for combustion air has how many square inches of free area when the manufacturers engineering data is not available?

Answer 14

432in²
When the manufacturers data is unknown:
Wood 25% free area
Metal 75% free area
A = 24 x 24
A = 576
FA = 576 x .75
FA = 432in²

Question 15

The minimum number of thread per inch allowed on 1in Schedule 40 steel pipe is ________.

Answer 15

10

Pg. 70 Fuel Gas Code

Question 16

You are sizing a corrugated stainless steel tubing gas pipe network that has a longest length of 83ft. The LP supplier has set a regulator at the house and it is delivering undiluted LP gas at 11inwc. The total connected load is 326,000btu/h, what size CSST pipe should you leave the regulator with if your design pressure drop is .5inwc and the specific gravity is 1.50?

Answer 16

EHD 39

Pg. 51 Fuel Gas Code

Question 17

The maximum length of a clothes dryer transition duct is limited to ________.

Answer 17

8ft

Pg. 124 Fuel Gas Code

Question 18

In general, floor furnaces shall have a minimum clearance from grade of not less than _______ inches.

Answer 18

6in

Pg. 122 Fuel Gas Code

Question 19

The appliance shut-off valve must be located no further from the appliance than_______.

Answer 19

6ft.

Pg. 77 Fuel Gas Code

Question 20

You are going to provide combustion air to a 90,000btu/h furnace with round horizontal ducts, what is the minimum size duct required?

Answer 20

8in
1in²/2000btu/h when communicating with the outdoors through horizontal ducts.
90,000btu ÷ 2000 = 45in²
Area = 45in²
Use the duct calculator to find an 8in duct has an area of 50in².
Pg. 18 Fuel Gas Code

Question 21

Brazing alloys shall not contain more than_____% phosphorous.

Answer 21

.05%

Pg. 70 Fuel Gas Code

Question 22

Boilers shall have all controls set, adjusted, and tested by _____________.

Answer 22

The boiler installer

Pg. 130 Fuel Gas Code