Natural Gas System Natural Gas System

Design Design

for Commercial and for Commercial and Industrial ApplicationsIndustrial Applications

March 16th 2006

www.piedmontng.com

Agenda: Supply – From the Wellhead to the Meter Properties of Natural Gas Service Fuel Piping

– Materials– Pipe Sizing– Pressure Regulation

Venting IFGC Code Updates

Supply

From the Wellhead to the Meter

What Is Natural Gas?

Combustible hydrocarbon gasses

Primarily methane (CH4)

Found in underground and undersea reservoirs – sometimes with crude oil wells

Result of long-time bacterial decomposition of plant and animal matter

24803

Petroleum System ElementsPetroleum System Elements

120° F120° F

350° F350° FGenerationGeneration

MigrationMigration

Seal RockSeal Rock

Reservoir RockReservoir Rock

OilOil

WaterWater

Gas CapGas Cap

EntrapmentEntrapment

Natural Gas Advantages

North American resource

Abundant worldwide

Wellhead Deregulated

Low impact underground infrastructure

Natural Gas Accounts for Roughly One-Fourth of U.S. Primary Energy Consumption

Sources of U.S. Gas Supply

U.S.84%

Canada15%

Liquified Natural Gas1%

The Impact of Severe Weather

Commodity Price Volatility

0

5,000

10,000

15,000

20,000

25,000

1973

1980

1990

2002

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d P

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$0.00

$0.50

$1.00

$1.50

$2.00

$2.50

$3.00

$3.50

$4.00

$4.50

Wel

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Natural Gas Wells Drilled

Real Wellhead Price

Natural Gas Drilling Activity Responds to Market Price

Major Portions of the Gas Resource Base are Not Accessible

21TCF

346TCF

31TCF

43TCF

100%

40%

100%

56%

Approximately 29 trillion cubic feet (TCF) of the Rockies gas resources are closed to development and 108 TCF are available with restrictions.

RestrictedPercentage

Liquefied Natural Gas (LNG)

Vapor is refrigerated to – 260 degrees Fahrenheit into a liquid form.

Reduces volume 600 times

Freighted to a LNG port and injected as a vapor back into the supply system.

Existing World LNG infrastructure moves about 6 Tcf/Year (40 Terminals and 128 ships mainly serving Japan, South Korea and Europe)

Producing Wells

Gathering LinesTransmission Lines

Processing Plant

CompressorStations

UndergroundStorage

Large Volume Customer

Regulator/Meter

City Gate(Regulators/Meters)

LNGor Propane/Air Plant

Natural Gas Transportation System

Residential Customers

CommercialCustomer

Distribution Mains (Lines)

Gas Market Sectors

Residential 25%

Commercial 15%

Power Generation 25%

Industrial 35%

Piedmont Natural Gas

Properties of Natural Gas

Natural gas is 96% Methane gas - CH4

Also contains small percentages of:Ethane 2.1%Propane <1%Butane <1%Pentane <1%Hexane <1%Heptane <1%

Flammability range

Requires between 4% - 14.% natural gas in air for combustion.– Less than 4% not enough fuel (Too Lean)– More than 14% too much fuel (Too Rich)– Peak burn is a 10% gas to air ratio

Properties of Natural Gas

Ignition Temperature

Above 1100º - 1200º– Pilot Lights– Sparks– Cigarettes– Static Electricity

Properties of Natural Gas

Properties of Natural Gas

Lighter than air, always rises Air has a specific gravity of 1.0 Natural gas has a specific gravity of 0.6 Propane 1.54

• Specific gravity is the weight of a substance compared to the weight of some referenced substance.

Propane ButaneNatural Gas

(Methane)

Chemical Formula C3H8 C4H10 CH4

Specific Gravity (Liquid) .509 .582 .3

Specific Gravity (Vapor) 1.52 2.01 .60 -.64

Weight Per Gallon 4.24 LBS. 4.84 LBS. LNG 4 +/- LBS.

Boiling Point (Atmospheric) - 44° F 31° F -260° F

Ignition Temperature 950° – 1050°900° -

1000°1100° - 1200°

Maximum Flame Temperature 3595° F 3615° F 3400° F

* Flammability Limits (Upper) 9.60 % 8.60 % 15 %

* Flammability Limits (Lower) 2.15 % 1.55 % 4 %

Ideal Combustion Ratio (Air to Gas)

24 to 1 31 to 1 10 to 1

Heat Value Per Cubic Foot (Vapor)

2,516 BTU 3,280 BTU 1,035 BTU

Heat Value Per Pound (Liquid) 21,591 BTU 21,221 BTU 20,833 BTU

Properties of Natural Gas

Natural gas is:• Odorless• Colorless• Non-Toxic

– Only through the displacement of oxygen can it pose an asphyxia hazard

• Non-Poisonous

Properties of Natural Gas Add Mercaptan as an odorant to aid in leak detection.

– Requirements:• Non-poisonous• Non-corrosive• Has to be retained by the gas• Has to burn completely• Not absorbed by pipe or containers• No harmful products from combustion

½ lb.per million cubic feet of natural gas

Properties of Natural Gas

Environmentally friendly Blue flame indicates proper &

complete combustion By-products of complete

combustion– Carbon Dioxide– Water Vapor

• Both are the same substances produced when you exhale.

    

Properties of Natural Gas

Incomplete combustion of produces a yellow/orange flame. Carbon Monoxide (CH) is a product of incomplete combustion, which is:

• Toxic• Poisonous• Explosive

Delivery of Natural Gas Service

Service Tap on Gas MainSaddle Fusion Joint

Service Tracer Wire

Natural Gas Service

Customer Piping starts at meter outlet

Standard Delivery Pressures

• 7 inches Water Column (0.25Psi)

• 2 Pounds per Square Inch

• 5 Pounds per Square InchElevated delivery pressures require equipment requirement

documentation and engineering approval. Not allowed to

reduce pipe size.

Why designing with Natural Gas is good for everyone

Facts

Virtually all electric power plants built in the US in the last 10 years are fueled with Natural Gas

Natural Gas power plants are expected to supply 90% of added electric loads in the US for the next 20 years

Delivering Energy to the Site

Electricity

Natural Gas

DeliveredTo Customer

28%

91 %

InGround

Extraction,Processing, &Transportation

Losses

ConversionLosses

DistributionLosses

100%

100%

92% 28%

92% 1%0%

Natural Gas Power Plant Consumption

Natural Gas Power Plants often can consume as much natural gas on and hourly basis as an entire metropolitan city’s direct connected gas load

Wonder why Gas Prices have been volatile lately?

What can we do to conserve our Natural Resource?

Design with Natural Gas !

When you Drink the Water Remember the Spring

Chinese Proverb