Chapter D

Question 1

When sizing gas piping systems, what is considered low pressure?

Answer 1

0.5 psig / 3.5 kPa is considered low pressure. Note: Although 2psig is high pressure, the fittings are included in the tables. 5psig and higher the fittings are not included and must be calculated in using the fitting tables in the codebook.

Question 2

1 kilowatt is how many BTU’s?

Answer 2

3412 BTU’s.

Question 3

1 cubic meter is how many cubic feet?

Answer 3

35.31 cubic feet.

Question 4

Are 2 psig gas pressures allowed inside one and two family dwellings?

Answer 4

Yes. The regulations also allow a 1.5 psig pressure drop, which allows increased gas flow.

Question 5

System pressure - Pressure drop = ?

Answer 5

Inlet pressure. (Ex. System Pressure of 2 psig - Pressure Drop of 1.5 psig = 0.5 psig Inlet Pressure.

Question 6

When sizing a gas piping system, is it more advisable to size the low pressure zone first or the high pressure zone?

Answer 6

The low pressure zone.

Question 7

When sizing a gas piping system, when do you include fittings?

Answer 7

When sizing systems 5 psig or greater include fittings. (Note: When reading the header of the gas sizing tables in the code book, it tells you whether or not you need to add fittings.)

Question 8

When including fittings in a high pressure gas piping system, do you include fittings which do not change the direction of the flow?

Answer 8

No, do not include fittings which do not change the direction of flow. (Tees on the run, pipe couplings, unions, reducing couplings, etc.)

Question 9

How are propane cylinders sized?

Answer 9

They are sized by the pounds of propane they can store. For example: a “100 pound cylinder” can store 100 pounds of propane.

Question 10

What is the range of sizes for propane cylinders?

Answer 10

1 pound to 500 pounds.

Question 11

How are propane tanks sized?

Answer 11

Propane tanks are sized by the gallons of water they can hold. These are expressed as gallons of water capacity “w.c.” For example: A “1000 gallon w.c.” tank can hold 1000 gallons of water.

Question 12

What is the range of sizes for propane tanks?

Answer 12

As small as 10 for gallons for motors, and up to 1000 gallons for residential and commercial use.

Question 13

Where is the design information located on cylinders?

Answer 13

On the neck ring of each cylinder are design markings and specifications.

Question 14

Where is the design information located on tanks?

Answer 14

The design information on tanks are stamped on a data plate and then attached to the tank.

Question 15

What are the three valves commonly used on cylinders and tanks?

Answer 15

The service, filler and safety valves.

Question 16

What are prestolite (POL) fittings used for?

Answer 16

Prestolite fittings are only used for vapor service connections.

Question 17

Are independant filler valves used on stationary cylinders or portable cylinders?

Answer 17

Stationary cylinders. Portable cylinders do not use independant filler valves because they’re filled through the service valve at the plant.

Question 18

What is the most common type of filler valve?

Answer 18

The double-back check valve is the most common.

Question 19

What is the purpose of a safety relief valve on a LP-gas container?

Answer 19

To automatically relieve excess pressure that can build up inside a cylinder or a tank. If this valve cannot perform properly the cylinder or tank may rupture.

Question 20

What is the pressure relief valve setting for cylinders?

Answer 20

375 psig.

Question 21

What is the pressure relief valve setting for tanks?

Answer 21

312 or 250 psig.

Question 22

When a fixed liquid level gauge emits a white fog or mist, what does this indicate?

Answer 22

This indicates that the maximum filling capacity has been reached and the filling operation must stopped.

Question 23

What must a stationary cylinder or tank contain?

Answer 23

A filler valve, a safety relief valve, a service valve, and a fixed liquid level gauge.

Question 24

Is LP-gas stored as a liquid or a vapor?

Answer 24

It’s stored as a liquid.

Question 25

What’s the maximum percentage a LP-gas container can be filled?

Answer 25

80%.

Question 26

What four things are necessary for corrosion to occur?

Answer 26

An anode, a cathode, an electrolyte, and a conductive path.

Question 27

What’s another name for anodes and cathodes?

Answer 27

Electrodes.

Question 28

What are the three methods of protecting underground piping from corrosion?

Answer 28

Protective coatings, electrical insulation, and cathodic protection.

Question 29

What must a good protective coating have?

Answer 29

A high dialectric rating.

Question 30

What test may be performed to check the quality of protective coatings?

Answer 30

The Jeep Test.

Question 31

List four types of approved electrical insulation fittings:

Answer 31

Insulated couplings, insulated unions, insulated flanges, and insulated meter spuds.

Question 32

What corrodes: anodes or cathodes?

Answer 32

Anodes corrode, cathodes don’t.

Question 33

What are two methods of providing cathodic protection?

Answer 33

Sacrificial anodes. and impressed current.

Question 34

When is impressed current used as a cathodic protection?

Answer 34

For large installations, involving several km of piping.

Question 35

Should sacrificial anodes be installed above or below the pipe it’s protecting?

Answer 35

Below the pipe.

Question 36

What are sacrificial anodes constructed of?

Answer 36

Magnesium.

Question 37

How many feet / meters should a sacrificial anode be installed below a pipe?

Answer 37

3 feet / 1 meter.

Question 38

How many feet / meters should a sacrificial anode be installed horizontally to the pipe?

Answer 38

2 feet / 0.6 meters.