E1 - Describe Gas piping and Tubing

Question 1

How does gas flow?

Answer 1

From high to low

Question 2

How is the amount of pressure in a pipeline measured?

Answer 2

psi

Question 3

What is the safest + most reliable way to deliver gas?

Answer 3

pipeline

Question 4

What is a “Christmas Tree”?

Answer 4

a production tubing that connects valves, pressure gauges to flow line connectors

Question 5

What is a major by product of NG?

Answer 5

Sulphur

Question 6

What does NG get compressed down to when transported?

Answer 6

5500 - 8000 kPa (800 - 1200psi)

Question 7

What speeds does NG travel at through pipelines?

Answer 7

11 - 32 km /h

Question 8

What reduces NG speed through pipelines? (FED)

Answer 8

distance, friction and elevation differences

Question 9

True or False: dt pressure decrease along pipelines –> pump boosters have to be used to increase pressure + speed

Answer 9

True

Question 10

How far apart are booster pumps placed?

Answer 10

80 -100 km

Question 11

Who is responsible for pipeline maintenance?

Answer 11

transmission companies

Question 12

Are LP gases transported in their gaseous state?

Answer 12

No, liquid state under pressure

Question 13

Before local utility can distribute the gas to customers, what has to happen?

Answer 13

Gas pressure has to be reduced

Question 14

How does the pressure reduction happen?

Answer 14

gas passes through a city or town gate

Question 15

What do the city gate stations control? (MOP)

Answer 15

metering, pressure limiting and odourization of gas

Question 16

What is added to NG to give it it’s distinct odor?

Answer 16

Mercaptan
(Mercaptan my captain)

Question 17

What does the pressure get reduced down to at the gate stations?

Answer 17

690 kPa (100 psi)

Question 18

What do storage tanks act as?

Answer 18

A buffer between transportation and distribution

Question 19

What is a base load?

Answer 19

Seasonal demand shifts

Question 20

What are peak loads?

Answer 20

unexpected demand surges

Question 21

What are 3 main types of underground storage? (SAD)

Answer 21

1) depleted gas reservoirs
2) aquifers
3) salt caverns

Question 22

True or False: LNG stored above ground occupies 600 times less space then being stored underground

Answer 22

True

Question 23

What is auto - refrigeration?

Answer 23

The release of gas from the liquid storage is also used to maintain remaining stored liquid at low temp.

Question 24

What is the Gas utility responsible for?

Answer 24

Installs and maintenance of gas service
(service line, riser, service stop (valve) service regulator and meter)

Question 25

What is the max pressure allowed for a single family dwelling?

Answer 25

2 psig (14 kPa)

Question 26

What is the max pressure allowed for an idustrial / commercial buildings?

Answer 26

5 - 20 psig (35 - 140 kPa)

Question 27

What types of pipe are allowed in gas applications?

Answer 27

Black iron, CSST, copper tubing, polyethylene plastic

Question 28

What is the gas fitter responsible for?

Answer 28

designing a piping system

Question 29

What is fluid dynamics?

Answer 29

the physics of the flow of fluid

Question 30

What is important when thinking about flow rates?

Answer 30

Affect of the gas pressure energy

Question 31

Flow in pipe is created by what?

Answer 31

energy loss dt friction

Question 32

How can one measure friction loss?

Answer 32

With 2 gauges at different points in the system

Question 33

Where would friction pressure drop be measured from on a system you're working from?

Answer 33

From the gas supply (metered or pressure regulator) and the most distant appliance

Question 34

What is the driving force that moves gas through a pipe?

Answer 34

pressure difference

Question 35

The greater the pressure difference, the greater the....

Answer 35

- volume and velocity of flow

Question 36

What are the 5 flow factors to consider?

Answer 36

1) Velocity 2) Pipe size 3) Density (SG) 4) Pipe Material 5) Fittings

Question 37

Friction loss in uniform, straight sections of pipe are greatly affected by?

Answer 37

Velocity of fluid

Question 38

What are 2 types of flow?

Answer 38

Laminar flow Turbulent flow

Question 39

Describe Laminar flow

Answer 39

- Flow is smooth --> streamline

Question 40

Where does laminar flow occur?

Answer 40

At lower velocities

Question 41

What type of flow has an energy loss?

Answer 41

Laminar

Question 42

Explain turbulent flow

Answer 42

- Has a rough flow

Question 43

What is a characteristic of turbulent flow?

Answer 43

Eddies or small pockets of fluid particles. (results in lateral mixing)

Question 44

What kind of flow increases friction loss?

Answer 44

Turbulent

Question 45

True or False: changing pipe size will change gas velocity

Answer 45

True

Question 46

What is the Shear rate?

Answer 46

it's the measure of fluids viscosity or slipperiness.

Question 47

Fluids w/ higher density require more what to move them?

Answer 47

Energy (and shear less easily)

Question 48

Specific gravity of a gas describes its density relative to what?

Answer 48

Air

Question 49

What is the SG of propane?

Answer 49

1.5

Question 50

What is the SG of NG?

Answer 50

0.6

Question 51

What is the SG of Butane?

Answer 51

2.0

Question 52

True or False: Less dense gases are easier to more.

Answer 52

True

Question 53

The amount of roughness on the inside of a pipe affects what?

Answer 53

Drag of the fluid

Question 54

When are eddies produced?

Answer 54

When the fluid is forced to change direction or go around a disruption

Question 55

Eddies produce what?

Answer 55

additional pressure loss

Question 56

What are the 3 different way to account for the friction loss of fittings?

Answer 56

1) Percentage of length 2) Pressure drop calculations 3) Equivalent length table

Question 57

Why is 20% added to the measured length?

Answer 57

It's a given allowance to account for the friction loss caused by fittings (It's a guess-tamation)

Question 58

Material not listed in the Gas code can be used if what?

Answer 58

-They conform to nationally recognized standards - A test report of a nationally recognized certification organization

Question 59

Steel piping is also called what?

Answer 59

Carbon steel or black iron pipe

Question 60

What wall thickness must steel pipe have?

Answer 60

schedule 40 or schedule 80 or standard weight depending on the application or size

Question 61

Can hot zinc coated pipe / fittings be used?

Answer 61

Yes

Question 62

What kind of copper is approved for gas use?

Answer 62

Type G, K, L

Question 63

What application are type G, K, and L only approved for?

Answer 63

Above ground and can't exceed 1 3/8" OD size

Question 64

Does the pipe sizes in the Gas code book go off OD or ID sizes?

Answer 64

OD

Question 65

True or False: Type K and L nominal tube size is 1/8" larger than its nominal size.

Answer 65

True

Question 66

What type of copper is approved for underground use?

Answer 66

Type K - must be soft annealed

Question 67

In order for Type L or G to be used underground, what must be applied to it?

Answer 67

External poly coating

Question 68

Can steel piping be used for gas systems?

Answer 68

yes but not common

Question 69

What is the pressure rating of a PE medium density pipe?

Answer 69

100 psi

Question 70

What is plastic pipe approved for only?

Answer 70

for outdoor, underground only

Question 71

What applications is plastic pipe good for?

Answer 71

gas mains, house service lines and after meter on premise underground lines

Question 72

When is plastic pipe to be inspected?

Answer 72

Before and after installation

Question 73

If there are any defects on the plastic pipe or fittings, what needs to be done?

Answer 73

It needs to be cut out and replaced

Question 74

Is PE thermoplastic?

Answer 74

Yes

Question 75

What does thermoplastic mean?

Answer 75

Softens when heated / solidifies when cooled (No chemical reaction takes place)

Question 76

PE piping is fused by applying what?

Answer 76

Heat and pressure

Question 77

Plain ended pipe is joined how?

Answer 77

butt fusion

Question 78

PE fittings are typically joined how?

Answer 78

socket fused

Question 79

How are tees often formed?

Answer 79

Saddle fusion

Question 80

Marking on PE should be at what intervals?

Answer 80

max 1.5m (4.9')

Question 81

What do the 4 digits on PE pipe represent?

Answer 81

1st number = density of pipe 2nd number = melt rating 3rd / 4th numbers = strength for density

Question 82

Is corrugated stainless steel tubing approved for gas?

Answer 82

Yes

Question 83

Up to what psi is corrugated stainless steel approved for?

Answer 83

5 psig

Question 84

What size of pipe does CSST come in?

Answer 84

3/8" - 2"

Question 85

What is a distinguishable feat of CSST pipe?

Answer 85

its yellow PE jacket on the outside

Question 86

How should CSST be installed?

Answer 86

As per manufacturer's instructions

Question 87

Do you have to take a training program prior to installing CSST?

Answer 87

Yes

Question 88

What is a benefit of using CSST pipe?

Answer 88

it's easy to weave through obstacles in one con't run

Question 89

What does black CSST pipe indicate?

Answer 89

That it's lightning - resistant

Question 90

What can't CSST pipe be used for?

Answer 90

as a gas connector

Question 91

What do gas connectors require?

Answer 91

flexible connection to connect to rigid permanently installed gas supply piping

Question 92

Choosing the correct connector depends on what? (Mo/dis/re/out)

Answer 92

- if there is repeat movement - repeat dis/reconnection requirements - be used outdoors

Question 93

What is the min working pressure that hose / hose fittings must have?

Answer 93

350 psig (2400kPa)