simplebooklet thumbnail

of 0
Operator Qualification Training
Task 70 Properties of Natural Gas &
Abnormal Operating Conditions (AOCs)
1
Natural Gas
One of the world’s cleanest and most reliable
sources of energy.
Very SAFE if handled correctly.
Extremely dangerous if handled incorrectly.
Two biggest potential dangers:
Fire/Explosion
Carbon Monoxide
Task 70 Properties of Natural Gas
2
Natural Gas
In this class we will answer the following questions:
What is natural gas?
Where does it come from?
What is it made of?
Why does it smell the way it does
Is it harmful?
What causes it to burn?
Task 70 Properties of Natural Gas
3
Natural Gas - General
Has been used as a fuel for thousands of years:
Oracle at Delphi, Greece (1000 BC) Mystical Flame
Desalination of Sea Water China (500 BC)
Commercialized Distribution for lighting
Great Britain (Late 1700’s)
Baltimore, MD (Early 1800’s)
Task 70 Properties of Natural Gas
4
Natural Gas - General
Occurs naturally in the Earth
Byproduct of the decay of plant
and animal matter over millions
of years Fossil Fuel
Petroleum Product
Found with oil
Found alone (hydro-fracking)
Task 70 Properties of Natural Gas
5
Natural Gas - General
A mixture of inert and light hydrocarbon gasses.
Is a gas at normal temperatures/pressures.
Consists mainly of:
METHANE
Task 70 Properties of Natural Gas
6
Natural Gas - General
Proportions of the mix of component gasses vary.
Task 70 Properties of Natural Gas
Component Range Sample 1 Sample 2
Methane
85-95%
85.19%
94.4%
Other Hydrocarbons
3-7%
Ethane
9.36%
3.22%
Propane
2.99%
0.59%
Butane
0.42%
0.21%
Pentane Plus
0.24%
0.07%
Non
-Hydrocarbons 2-8%
Nitrogen
1.80%
1.46%
Carbon Dioxide
0.05%
7
Natural Gas - General
Natural Gas is LIGHTER THAN AIR!
Specific gravity/vapor density = ±0.55-0.65
Outside, it rises rapidly and mixes readily into the
atmosphere.
Inside, it rises to the highest level and accumulates
down.
Task 70 Properties of Natural Gas
8
Natural Gas Physical Properties
True or False:
Natural Gas is Odorless and Tasteless.
Task 70 Properties of Natural Gas
FALSE!
9
Natural Gas Physical Properties
True or False:
Natural Gas is Odorless and Tasteless.
And TRUE!
In its natural state, it is an odorless and tasteless gas!
An ODORANT called Mercaptan is added to
give natural gas a recognizable smell.
Task 70 Properties of Natural Gas
FALSE!
10
Natural Gas Physical Properties
True or False:
Natural Gas is Odorless and Tasteless.
And TRUE!
In its natural state, it is an odorless and tasteless gas!
An ODORANT called Mercaptan is added to give
natural gas a recognizable smell.
SAFETY measure to aid in leak detection.
Task 70 Properties of Natural Gas
11
Natural Gas Physical Properties
Natural Gas is
You cannot see it.
It is NON-TOXIC and NON-POISONOUS
CAUTION: It will suffocate if replaces/displaces air in an
area or space.
It is COMBUSTIBLE!
Burns when mixed with air and an ignition source.
Gives it its value, but makes it dangerous!
Task 70 Properties of Natural Gas
COLORLESS!
12
Natural Gas Physical Properties
Temperature~Density~Pressure Relationship:
Kinetic Theory of Matter:
Matter is made up of atoms & molecules in motion.
Add heat (energy), and they vibrate faster and move apart
(become less dense)
Remove heat (cool it down), movement
slows and they come closer together
(become more dense).
When this happens to natural gas inside a pipeline, what happens
to pressure?
Task 70 Properties of Natural Gas
13
Natural Gas Physical Properties
Compression~Density~Pressure Relationship:
Boyle’s Law: ...for a fixed mass, the absolute pressure and the
volume of a gas are inversely proportional.
As volume decreases and gas is
compressed, the pressure and
density increase.
When natural gas is compressed
inside a pipeline, what happens
to pressure and density?
Task 70 Properties of Natural Gas
14
LET’S REVIEW
Natural Gas is a mixture of gasses consisting mainly of:
METHANE
Is it lighter than air or heavier than air?
LIGHTER
Task 70 Properties of Natural Gas
15
LET’S REVIEW
Does Natural Gas smell?
Why is the ODORANT added?
What happens to the density of a gas when heated?
When cooled?
How could this affect pressure in the pipeline?
What happens to the density of a gas when compressed?
How could this affect pressure in the pipeline?
Task 70 Properties of Natural Gas
16
Natural Gas - Combustion
Hydrocarbons are a combination of Hydrogen and
Carbon atoms.
When hydrocarbons burn, the Hydrogen atoms
combine with Oxygen atoms in the air to form
H2O-Water.
When combustion is complete, the Carbon atoms
combine with Oxygen atoms to form CO2-Carbon
Dioxide.
Task 70 Properties of Natural Gas
17
Natural Gas Combustion
Complete Combustion
Task 70 Properties of Natural Gas
18
Natural Gas Combustion
When combustion is incomplete, the Carbon atoms
combine with Oxygen atoms to form CO-Carbon
Monoxide.
Incomplete Combustion
Task 70 Properties of Natural Gas
19
Natural Gas - Combustion
For combustion to occur, fuel must mix with air in
the presence of an ignition (heat) source.
There must also be a
sustainable chemical
chain reaction for
combustion to continue.
Task 70 Properties of Natural Gas
20
Natural Gas - Combustion
The fuel and oxygen must mix in very specific amounts
for the chemical chain reaction to occur.
Too much fuel + not enough oxygen = Mixture is too RICH!
Too much oxygen + not enough fuel = Mixture is too LEAN!
NO FIRE
Every combustible substance (fuel) has minimum and
maximum fuel-to-oxygen percentage mixtures that will
allow for combustion to occur.
Task 70 Properties of Natural Gas
21
Natural Gas Flammability Range
The minimum percentage of fuel required for
combustion is called the LOWER FLAMMABLE
LIMIT (LFL) or LOWER EXPLOSIVE LIMIT (LEL).
The maximum percentage of fuel that will allow
combustion is called the UPPER FLAMMABLE LIMIT
(UFL) or UPPER EXPLOSIVE LIMIT (UEL).
Task 70 Properties of Natural Gas
22
Natural Gas Flammability Range
IMPORTANT
Task 70 Properties of Natural Gas
23
Natural Gas Flammability Range
The LOWER EXPLOSIVE LIMIT of Natural Gas is
4.5% (5%) gas in a volume of air.
Lesser concentrations are too lean to burn.
The UPPER EXPLOSIVE LIMIT of Natural Gas is
14.5% (15%) gas in a volume of air.
Higher concentrations are too rich to burn.
Task 70 Properties of Natural Gas
24
Natural Gas Flammability Range
The IDEAL mixture for burning natural gas is approximately:
10% Gas & 90% Air
Air is approximately 20-21% oxygen
Fuel : Oxygen = 10% Natural Gas : 20% oxygen
1 CH
4
(Methane) : 2 O
2
(Oxygen)
Task 70 Properties of Natural Gas
25
Natural Gas - Combustion
The fuel/oxygen mix is only one part of the
controlled combustion of Natural Gas.
Gas pressure must be controlled.
Equipment must functional and correctly vented.
Task 70 Properties of Natural Gas
26
Natural Gas - Combustion
Uncontrolled combustion occurs when something
goes wrong or gas is allowed to accumulate before
ignition.
Results can be catastrophic.
Task 70 Properties of Natural Gas
27
Natural Gas - Combustion
Task 70 Properties of Natural Gas
28
Natural Gas - Combustion
Note the wide flammability range of Carbon Monoxide (CO). Most people know about the suffocation
danger of CO, but not how flammable it is.
Task 70 Properties of Natural Gas
Gas Formula Ignition Point LEL/LFL UEL/UFL
Methane CH
4
Approx. 1193°F 5.3% 15.0%
Ethane C
2
H
6
993-1101°F 3.0% 12.5%
Propane C
3
H
8
957-1090°F 2.2% 9.5%
Butane C
4
H
10
912-1056°F 1.9% 8.5%
Natural Gas Blend 1100-1200°F 5% 15%
Gasoline Blend Approx 632°F 1.4% 7.5%
Carbon Monoxide
CO 1191-1216°F 12.5%* 74.0%*
Hydrogen H
2
1076-1094°F 4.0% 75.0%
Hydrogen Sulfide H
2
S 655-714°F 4.3% 45.0%
29
LET’S REVIEW
What 4 things are needed for combustion to occur?
Fuel, Oxygen, Ignition Source and a Chemical Chain Reaction.
The flammable range of Natural Gas is:
5% - 15%
(4.5% - 14.5%)
What are some potential ignition sources you may encounter?
Electric Arcs, Static Electric Spark, Cell Phone, Smoking, Engines, Light
Switches, Doorbells, Open Flames, etc.
Task 70 Properties of Natural Gas
30
Abnormal Operating Conditions (AOCs)
The natural gas delivery system MUST function properly at
all times in order to deliver the correct amount of gas to
keep up with demand.
AOC (def.): Any condition that may indicate a malfunction
of a component or deviation from normal operations that
may indicate a condition exceeding design limits or result
in a hazard to persons, property or the environment.
Task 70 Abnormal Operating Conditions
31
Abnormal Operating Conditions (AOCs)
All personnel performing covered tasks on behalf of PPS
must be able to recognize and react to an abnormal
operating condition.
Client approval may be necessary prior to taking certain
corrective actions.
This could include, but is not limited to closing line valve(s) to
isolate an affected area or controlling pressures or flows.
Task 70 Abnormal Operating Conditions
32
ESCAPING GAS
Any unplanned or uncontrolled release of gas.
How do you recognize it?
Task 70 Abnormal Operating Conditions
33
ESCAPING GAS
Any unplanned or uncontrolled release of gas.
How do you recognize it?
Task 70 Abnormal Operating Conditions
34
ESCAPING GAS
Any unplanned or uncontrolled release of gas.
How do you recognize it?
Task 70 Abnormal Operating Conditions
35
ESCAPING GAS
Any unplanned or uncontrolled release of gas.
How do you recognize it?
Task 70 Abnormal Operating Conditions
36
FIRE/EXPLOSION
The unplanned or uncontrolled ingition of gas.
How do you recognize it?
Task 70 Abnormal Operating Conditions
37
NO GAS
No gas pressure in the main or service caused by, but not
limited to inadvertent shut down, water or severed line.
Can cause gas supply interruption, causing pilot lights to go out.
Can cause buildings to fill with gas if supply is suddenly restored.
How do you recognize it?
Customer complaints
Pressure Gauge readings
Task 70 Abnormal Operating Conditions
38
EXCESSIVE PRESSURE
Pressure that exceeds system’s normal operating limits.
Pressure could exceed the MAOP of the system
MAOP = Maximum Allowable Operating Pressure
How do you recognize it?
Could cause failure of system components
Regulator Damage/Failure
Ruptured pipelines
Task 70 Abnormal Operating Conditions
39
EXCESSIVE PRESSURE
Pressure that exceeds system’s normal operating limits.
Pressure could exceed the MAOP of the system
MAOP = Maximum Allowable Operating Pressure
How do you recognize it?
Could cause failure of system components
Regulator Damage/Failure
Ruptured pipelines
Customer appliance damage
Can cause high pilot lights that can lead to fires.
Can blow out pilot lights and fill structure with unchecked gas leading to fire
or explosion.
Task 70 Abnormal Operating Conditions
40
EXCESSIVE PRESSURE
Pressure that exceeds system’s normal operating limits.
How do you recognize it?
Should trigger pressure relief devices.
Task 70 Abnormal Operating Conditions
41
EXCESSIVE PRESSURE
Pressure that exceeds system’s normal operating limits.
How do you recognize it?
Pressure gauge readings
higher than normal line pressure.
Any pressure reading above
MAOP.
Task 70 Abnormal Operating Conditions
42
INADEQUATE PRESSURE
Pressure that falls below the system’s normal operating
limits.
Could indicate pressure regulator malfunction.
May not supply enough gas to keep up with demand.
How do you recognize it?
Could cause low pilot
flame or pilot outage.
Can cause poor burner
flame quality
Task 70 Abnormal Operating Conditions
43
INADEQUATE PRESSURE
Pressure that falls below the system’s normal operating
limits.
How do you recognize it?
Pressure gauge readings
lower than normal line pressure.
Task 70 Abnormal Operating Conditions
44
IMPROPER ODORIZATION
Excessive or Inadequate odorization of the gas,
including an odorant spill or release.
How do you recognize it?
Too much odorant:
Can cause eye, skin or respiratory irritation.
Too little odorant:
Unable to detect leaking gas.
Task 70 Abnormal Operating Conditions
45
ENVIRONMENTAL INCIDENT
The spill or release of environmentally hazardous
materials such as odorant, asbestos, PCB or
condensate.
How do you recognize it?
Disintegration/release of hazardous solids:
Example: Asbestos pipe coating made friable and airborne.
Liquid spill of hazardous chemicals/fluids
Example: Gas Condensate Fluids that can build up inside
pipeline. Very hazardous and generally contain PCBs.
Task 70 Abnormal Operating Conditions
46
UNSAFE ATMOSPHERE IN A CONFINED SPACE
Any hazardous atmosphere in a confined space.
A hazardous atmosphere containing any of the
following:
Oxygen (O2) level less than 19.5% or greater that 23.5%
Combustible Gas level of 10% LEL or greater
Hydrogen Sulfide (H2S) level greater than 10 ppm
Carbon Monoxide (CO) level greater than 15 ppm
How do you recognize it?
Air testing/monitoring
Task 70 Abnormal Operating Conditions
47
DAMAGED FACILITIES
Any damage to a pipeline or pipeline component
cause by an outside influence.
Examples:
Third party damage:
Broken Pipe
Task 70 Abnormal Operating Conditions
48
DAMAGED FACILITIES
Any damage to a pipeline or pipeline component
cause by an outside influence.
Examples:
Third party damage:
Broken Pipe
Bent Piping
Dented Piping
Task 70 Abnormal Operating Conditions
49
DAMAGED FACILITIES
Any damage to a pipeline or pipeline component
cause by an outside influence.
Examples:
Third party damage:
Broken Pipe
Bent Piping
Dented Piping
Coating Gouges
Task 70 Abnormal Operating Conditions
50
DAMAGED FACILITIES
Any damage to a pipeline or pipeline component
cause by an outside influence.
Examples:
Corrosion:
Task 70 Abnormal Operating Conditions
51
DAMAGED FACILITIES
Any damage to a pipeline or pipeline component
cause by an outside influence.
Examples:
Gouges/Scratches on
Polyethylene Pipe
≥ 10% of the sidewall:
Task 70 Abnormal Operating Conditions
52
DAMAGED FACILITIES
Any damage to a pipeline or pipeline component
cause by an outside influence.
Examples:
Washed Out,
Uncovered, or
Undermined Pipeline:
Task 70 Abnormal Operating Conditions
53
EQUIPMENT/COMPONENT FAILURE
The failure of equipment or a pipeline component
to perform in the manner for which it is designed.
Examples:
Regulator Failure:
Can cause Excessive Pressure, Inadequate Pressure or No Gas
scenarios.
Loss of Completion Plug during Tapping/Stopping:
Unable to remove tapping/stopping equipment from main.
Valve stuck/inoperable:
Unable to stop or isolate gas flow.
Task 70 Abnormal Operating Conditions
54
REACTION PROCEDURES
Every situation is unique.
No set of instructions can replace the judgment
exercised by the individual in the field as to what
steps should be taken, and in what order.
The following list provides guidance with the
actions an individual may elect to take in response
to abnormal operating conditions.
Task 70 Abnormal Operating Conditions
55
ESCAPING GAS
Protect life and property
At a minimum, notify PPS Management and/or the
appropriate Client Representative/Department
Eliminate all potential ignition sources (vehicle engines,
open flames, non-intrinsically safe lighting, etc.)
Ensure a fire extinguisher is upwind
Stop the flow of gas and eliminate the hazard (make safe)
Test for gas in and around nearby buildings for possible
migration
Standby and wait for assistance
Task 70 Abnormal Operating Conditions
56
FIRE/EXPLOSION
Protect life and property
At a minimum, notify PPS Management and/or the
appropriate Client Representative/Department
Man the fire extinguisher
Let the fire burn if there is NO threat to life or property
Stop the flow of gas to the affected area (make safe)
Test for gas in and around nearby buildings for possible
migration
Standby and wait for assistance
Task 70 Abnormal Operating Conditions
57
NO GAS
Protect life and property
At a minimum, notify PPS Management and/or the appropriate
Client Representative/Department
Install pressure monitoring devices to verify system pressure
Determine the extent of the affected area
Isolate the affected area (make safe)
Shut off all affected customers at the service valve or gas meter
Review actions that may have caused the loss of gas
Standby and wait for assistance
Task 70 Abnormal Operating Conditions
58
EXCESSIVE PRESSURE
Protect life and property
At a minimum, notify PPS Management and/or the
appropriate Client Representative/Department
Reduce the pressure to eliminate the hazard (make safe)
Test for gas in and around nearby buildings for possible
migration
Check gas appliances for possible damage
Review actions that may have caused the excessive
pressure
Standby and wait for assistance
Task 70 Abnormal Operating Conditions
59
INADEQUATE PRESSURE
Protect life and property
At a minimum, notify PPS Management and/or the appropriate
Client Representative/Department
Review system maps
If outages are occurring, isolate the affected services and shut
them off at the service valve or gas meter
Attempt to stabilize and increase system pressure if no outages
are occurring
Review actions that may have caused the inadequate pressure
Standby and wait for assistance
Task 70 Abnormal Operating Conditions
60
IMPROPER ODORIZATION
Protect life and property
At a minimum, notify PPS Management and/or the
appropriate Client Representative/Department
Eliminate all potential ignition sources (vehicle engines,
open flames, non-intrinsically safe lighting, etc.)
Adjust the odorizer to compensate for the improper
odorization level (make repair)
Standby and wait for assistance
Task 70 Abnormal Operating Conditions
61
ENVIRONMENTAL INCIDENT
Protect life and property
At a minimum, notify PPS Management and/or the
appropriate Client Representative/Department
Eliminate all potential ignition sources (vehicle engines,
open flames, non-intrinsically safe lighting, etc.)
Don appropriate Personal Protective Equipment (PPE)
Control or contain the spill
Standby and wait for assistance
Task 70 Abnormal Operating Conditions
62
UNSAFE ATMOSPHERE IN A CONFINED SPACE
Protect life and property
At a minimum, notify PPS Management and/or the
appropriate Client Representative/Department
Eliminate all potential ignition sources (vehicle engines,
open flames, non-intrinsically safe lighting, etc.)
Man the fire extinguisher
Follow PPS’ procedures for hazardous atmospheres in
confined spaces
Standby and wait for assistance
Task 70 Abnormal Operating Conditions
63
DAMAGED FACILITIES
Protect life and property
At a minimum, notify PPS Management and/or the
appropriate Client Representative/Department
Eliminate all potential ignition sources (vehicle engines,
open flames, non-intrinsically safe lighting, etc.)
Evaluate the damage and make repairs
Standby and wait for assistance
Task 70 Abnormal Operating Conditions
64
EQUIPMENT/COMPONENT FAILURE
Protect life and property
At a minimum, notify PPS Management and/or the
appropriate Client Representative/Department
Eliminate all potential ignition sources (vehicle engines,
open flames, non-intrinsically safe lighting, etc.)
Evaluate the cause of the failure and make repairs
Standby and wait for assistance
Task 70 Abnormal Operating Conditions
65
QUESTIONS?
Task 70 Properties of Natural Gas & AOCs
66