Gas Piping

Question 1

What types of gas piping materials can be used

Answer 1

Steel
Copper
Plastic

Question 2

What schedule of black iron pipe is used for gas connections

Answer 2

Schedule 40

Question 3

NPS stands for?

Answer 3

Nominal Pipe Size

Question 4

What do the sizes range from in regards to the length of “nipples”

Answer 4

1/2” increments up to 6 “
1” increments 7”-12”

Question 5

Are close nipples allowed to be used in gas systems

Answer 5

No

Question 6

ASPT and NPT stand for what ?

Answer 6

American Standard Pipe Thread
National Pipe Thread

Question 7

Is the pipe threads tapered

Answer 7

Yes

Question 8

What is the approximate number of threads to be cut for a nominal pipe size of 1/2”

Answer 8

10 1/2

Question 9

Name the different types of pipe cutters available

Answer 9

Single wheel and multi wheel

Question 10

What tool is used to remove the internal hurt from cut pipe

Answer 10

Straight fluted reamer and spiral fluted reamer

Question 11

Why is the use of cutting oil so important when threading iron pipe

Answer 11

Safeguard against poor threads, die wear, clearing debris, and heat

Question 12

What type of black iron fitting is not allowed to be used for gas system

Answer 12

Street elbow

Question 13

When ordering a balck iron tee what is the last size normally

Answer 13

Branch size

Question 14

What is the purpose for the usage of a union

Answer 14

Easy quick assembly and disassembly of pipings stems

Question 15

Bushing reduce pipe sizes, what is not permitted when using bushings

Answer 15

Nesting bushings

Question 16

What must be used in every black iron connection

Answer 16

Teflon tape and pipe compound

Question 17

Where is the pipe compound placed

Answer 17

Male pipe threads

Question 18

How is Teflon tape wrapped on the male thread

Answer 18

Clockwise, 50% overlap, first two threads bare

Question 19

What should not be in contact with the pipe when using a pipe wrench to tighten a fitting together

Answer 19

Back of the hook jaw

Question 20

What is the purpose for a dirt pocket

Answer 20

Collects foreign materials before reaching the appliance

Question 21

List the rules for a dirt pocket

Answer 21

3” nipple with a cap , Diana eye rod the pocket has to be the same size as the drop and has to be accessible

Question 22

Can gas materials be reused

Answer 22

As long as they are clean and inspected

Question 23

List the approved gas leak detectors

Answer 23

Soapy water, sniffer

Question 24

What should not be used to check for gas leaks

Answer 24

Flame

Question 25

What’s re the three classifications of copper

Answer 25

Malleable, ductile, food resistance to corrosion

Question 26

List the copper types color

Answer 26

k: green
L: blue
M: red

Question 27

Using stainless corrugated tubing, the appliance has to be approved, what are some of the requirements for the appliance

Answer 27

Suspended appliance, decorative appliance , or a direct vent room heater if it is not free standing