Introduction to Gasfitting Codes and Regulations - Part B

Question 1

All plastic gas lines being buried must have a what?

Answer 1

Tracer wire so it can be energized to search for the pipe.

Question 2

Can gas pipe be used as a conductor?

Answer 2

Only!! if it’s incorporated as part of the flame safeguard of the appliance.

Question 3

Can piping pass under a foundation or footing?

Answer 3

No.

Question 4

Can you repair defective pipe or fittings?

Answer 4

No, it must be replaced.

Question 5

Do you need to increase the pipe size of the existing gas line when tapping into it within 2 feet of the gas meter/regulator?

Answer 5

No.

Question 6

How do you install gas lines in concrete?

Answer 6

Encased in a duct having both ends open to the atmosphere with at least 1/2” air space around the pipe or
Suspended in a trench with a removable top that is not airtight.

Question 7

How do you test finish piping?

Answer 7

With soapy water solution and a 10 minute meter test dial test

Question 8

How does residential gas piping need to be labeled?

Answer 8

The same as commercial but every 6ft instead of 20ft

Question 9

How far away can a gas cock be installed from an appliance for residential purposes?

Answer 9

Up to 50 ft as long as it’s accesible and clearly tagged

Question 10

How far from the edges of a member do holes have to be?

Answer 10

2 inches minimum and the hole diameter must not exceed more than a 1/4 of the member depth

Question 11

How far must a purge point be from the building?

Answer 11

At least 10ft

Question 12

How is pipe dope applied?

Answer 12

To the male threads so that excess dope is forced out of the pipe rather than pushed into it.

Question 13

If you’re installing larger gas line to existing tubing, where do you install it?

Answer 13

Within 2 feet of the gas meter/regulator

Question 14

Minimum size for a pressure test gauge for gas

Answer 14

3 inches

Question 15

What are the fittings required to make a drip/dirt pocket?

Answer 15

1. A tee
2. A cap
3. A nipple

Question 16

What are the maximum temperatures a hose can be subjected to?

Answer 16

125F

Question 17

What are the restrictions to using a hose?

Answer 17

It shall not exceed 10ft and cannot pass through any sort of wall or barrier.

Question 18

What circumstances is a hose used for?

Answer 18

Commercial or industrial work where it’ll be exposed to vibration, expansion, contraction

Question 19

What do you need to be careful about when purging gas lines larger than 4”?

Answer 19

You need to remove all the air used in a pressure test with an inert gas prior to allowing gas to enter the system to avoid dangerous gas/air mixtures

Question 19

What color of teflon tape is approved for gasfitting?

Answer 19

Yellow, pink, light orange, or light green (they are thicker)

Question 20

What is needed on piping that will be exposed to a corrosive atmosphere?

Answer 20

Painting or coating.

Question 20

What does a dirt pocket do?

Answer 20

Collects scale, fillings, and foreign materials that may be in the gas line.

Question 21

What is the maximum allowable pressure drop in a high pressure system (above 14”wc)?

Answer 21

50% of standing pressure

Question 22

What is the maximum allowable pressure drop on a low pressure (7-14”wc) system?

Answer 22

1” wc

Question 23

What is the minimum depth for underground piping?

Answer 23

15” but 24” under any commercial driveway

Question 24

What is the minimum size for a dirt pocket?

Answer 24

3 inches

Question 25

What is the minimum spec for a hose?

Answer 25

350 psig working pressure

Question 26

What is the minimum test for rough in piping?

Answer 26

15psig for 15 minutes

Question 27

What kind of fittings can you use in welded pipe installations?

Answer 27

Manufactured only, not field fabricated

Question 28

What kind of labeling does gas line need in commercial or industrial applications?

Answer 28

A yellow mark or any labeling that indicates it’s gas line at least every 20ft

Question 29

What locations are not suitable for gas line installations?

Answer 29

Stairwells (doesn’t include residential), chimneys, flues, elevator shafts and some others

Question 30

What needs to be done to piping when passing through concrete or brick?

Answer 30

It needs to be protected from the corrosive effects of those materials

Question 31

What materials can gaskets used in gas systems be made of?

Answer 31

Not rubber, has to be synthetic or cork.

Question 32

What range should the gauge you’re using have?

Answer 32

It should exceed the pressure by 15% but not by more than 300%

Question 33

What type of copper requires no special coating?

Answer 33

Type K

Question 34

What type of copper comes coated?

Answer 34

Type L

Question 35

When can threaded bushings be used on gas lines?

Answer 35

When they’re approved

Question 36

When can you leak test and not pressure test gas line additions?

Answer 36

When they’re less than 20ft and below 0.5 psig

Question 37

Where are dirt pockets located?

Answer 37

In the gas pipe at the bottom of the final drop to an appliance

Question 38

Where can you find the Btu input of an appliance?

Answer 38

The rating plate, installation instructions, or by contacting the manufacturer

Question 39

Where must Unions and Swing joints be installed?

Answer 39

Anywhere that is not concealed as they can loosen over time.