ILM 110205g , 080105cA, 080106c Gas Piping

Question 1

What types of gas piping materials can be used?

Answer 1

Black iron, plastic (polyethelene), copper

Question 2

What schedule of black iron pipe is most commonly used for gas connections?

Answer 2

Schedule 40

Question 3

NPS stands for

Answer 3

Nominal Pipe Size

Question 4

Which 3 fittings cannot be used in a gas piping system?

Answer 4

• Street tee
• Street elbow
• Close nipple

Question 5

NPT stands for ______ and what is the included angle on a perfect thread?

Answer 5

National Pipe Thread
60 degree

Question 6

What is the approximate number of threads to be cut for a nominal pipe size of ½”?

Answer 6

10 1/2

Question 7

What tool is used to remove the internal burr from cut pipe?

Answer 7

Reamer

Question 8

Why is removing the internal burr so important?

Answer 8

To ensure a smooth flow. If the burr is not removed, pipe pressure loss, turbulence and catching foreign material is a possibility.

Question 9

After securing the pipe to the pipe vise, what steps are followed to thread the pipe?

Answer 9

Measure
mark
cut
clean die threads
ream
thread and oil.

Question 10

Bushings reduce pipe sizes, what is not permitted when using bushings?

Answer 10

Nesting

Question 11

How is Teflon tape applied to the thread? What is the purpose of the Teflon tape?

Answer 11

Teflon tape is used as a lubricant to be applied to the male threads, clockwise with a 50% overlap
leaving the first 2 threads bare.

Question 12

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

Answer 12

Hook jaw

Question 13

What is the purpose of a dirt pocket?

Answer 13

They are designed to collect scale, filings and foreign
materials that may be present in the gas line before they reach the appliance.

Question 14

What is the purpose of a nipple chuck?

Answer 14

To hold short pieces of pipe without damaging existing threads

Question 15

Can gas materials be reused?

Answer 15

Yes if they are deemed to be in acceptable condition

Question 16

List three approved gas leak detectors.

Answer 16

Soapy water solution
methane gas leak detector
clocking the meter

Question 17

What should not be used to check for gas leaks?

Answer 17

Flame

Question 18

What is cutting oil used for?

Answer 18

Keep the die or tool cool

Question 19

List the following uses for the below copper types: K, L, M, G

Answer 19

K,L,G - gas
M - water

Question 20

What material can be used above ground and doesn’t require fittings to change direction?

Answer 20

CSST -corrugated stainless steel tubing

Question 21

Under the general gas code information, who is responsible for the safe operation and startup of any appliance?

Answer 21

The installer

Question 22

Describe thread engagement?

Answer 22

A short length of pipe that is used in the makeup of the
fitting or is threaded into the fitting is called the thread engagement.

Question 23

Where can aluminum tubing be used?

Answer 23

Pilot gas from gas valve to pilot burner

Question 24

For any appliance to be approved for installation, it requires what on the appliance?

Answer 24

Rating plate

Question 25

What is the purpose of a regulator and what is it called when the flow of gas is completely stopped by the regulator?

Answer 25

The regulator is a piece of equipment that reduces and maintains a set pressure while compensating for volume in a gas system. It is known as lock up when gas is completely stopped by the regulator.

Question 26

What is installed in a regulator to restrict the volume of gas escaping from the regulator vent in case the diaphragm ruptures?

Answer 26

Ball check leak limiting device

Question 27

What is the minimum clearance required for the service side of a furnace?

Answer 27

2' or 24 "

Question 28

A regulator must be installed with a manual _______ valve located upstream of the regulator to accommodate maintenance and service requirements.

Answer 28

shut off

Question 29

In which direction is an orifice drilled and how many sizes smaller of a bit would you use?

Answer 29

Drilled in the direction of gas flow with a bit 2 sizes smaller.

Question 30

If a heat exchanger is found to be defective, what must be done to the heat exchanger in a residential situation?

Answer 30

Replaced

Question 31

How far must a regulator vent terminate from a mechanical air intake?

Answer 31

10’ or 3m

Question 32

What is the only type of copper fitting that can be used on gas line connections?

Answer 32

Flare fitting

Question 33

What are the 3 main elements of a regulator? What is the purpose of each element?

Answer 33

**Restricting element** - limits gas flow **Measuring element** - measures outlet (downstream) pressure **Loading element** - raise or lower outlet pressure

Question 34

What must be done to an appliance that was previously installed in Calgary and is now being installed at 6750’?

Answer 34

Derate 9% 6750 – 4500 =2250 (Derate 4% for every 1000’ or 1% for every 250’)