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Sack Breakers
Sacks filled with dirt or sand and cement, approximately one cubic foot, used to prevent erosion; or to form a barrier between pipelines and prevent coating or pipe damage when lowering in rocky trenches.
Saddle
A fitted plate held in place by clamps, straps, heat fusion, or welding over a hole punched or drilled in a gas main to which a branch line or service line connection is made. The saddle also may serve as a reinforcing member for repair.
Safety Coupling
A friction coupling adjusted to slip at a predetermined torque to protect the rest of the system from overload.
Safety Education (Training)
The transmission of knowledge, skills, attitudes, motivations, etc., concerning the safety requirements of operations, processes, environments, etc., to workers, supervisors, managers, and others. The objective of safety education and training is favorable behavior change.
Safety Engineering
The planning, development, improvement, coordination and evaluation of the safety component of integrated systems of people, materials, equipment and environments to achieve optimum safety effectiveness in terms of protection of people and property.
Safety Hats
Rigid headgear of varying materials designed to protect the workman's head -- not only from impact, but from flying particles and electric shock or any combination of the three. Safety helmets should meet the requirements of American Standard Z89, Standard For Industrial Protective Helmets.
Safety Shoes
Generally applies to footwear providing toe protection for the wearer. Safety-toe footwear has been divided into three classifications: 75, 50, and 30; based on its ability to meet the minimum requirements for both compression and impact as specified by the American Standard Z41 Series. Generally, the safety-toe shoe should be used for work requiring the handling of heavy materials. Safety shoes may also be obtained with conductive soles to drain off static charges, and with nonferrous construction, to reduce the possibility of friction sparks in environments with a fire or explosion hazard. Other safety shoes are designed to provide protection against splashes of molten metal, construction hazards such as protruding nails, contact with energized electrical equipment, wet conditions, hot surfaces, and other hazards.
Safety Shutoff
See VALVE, SAFETY SHUTOFF.
Safety Shutoff Device
A device that will shut off the gas supply to the controlled burner(s) in the event the source of ignition fails. This device may interrupt the flow of gas to the main burner(s) only or to the pilot(s) and main burner(s) under its supervision.
Safety Solvents
Solvents which are free from fire or toxicity hazards and are nondamaging to surfaces or materials being cleaned. This term is often misused. Depending on the conditions of use, none of these criteria may be met by so-called "safety solvents". For example, petroleum hydrocarbons are effective solvents, low in toxicity, and inexpensive but have relatively low flash and fire points. The following conditions must be kept in mind by users of "safety solvents": 1.The toxicological effects alone are not adequate to assess the hazard potential of a solvent. 2.The vapor pressure, ventilation, and manner of usage will determine the concentration in air. 3.Handling procedures and type of clothing will determine the degree of skin contact and absorption. 4.Ignition temperature, flash point, and other factors determining the potential for fire and explosion must be considered.
Safety-Control Circuit
A circuit classified as a safety-control circuit is one involving one or more safety controls in which failure due to grounding, opening, or shorting of any part of the circuit can cause unsafe operation of the valve or the controlled equipment.
Salamander
See HEATER, CONSTRUCTION.
Sales Agreement
An agreement between a purchaser/buyer and seller (e.g., producer, marketer, pipeline, LDC) which defines the terms and conditions of a purchase/sale and title transfer of gas quantities.
Sales for Resale
Sales made to a local distribution company, pipeline, or municipality where the gas will be resold by the purchaser.
Sales Level
The sales volume being applied to the cost of service to develop rates. See TRANSPORTION LEVEL, THROUGHPUT LEVEL.
Sales Refund Objective (SRO)
A provision included in many prior settlements, and often examined by Staff, that if actual volumes exceed an agreed level during the period of time the rates are in effect, the pipeline agrees to refund the fixed costs received in the commodity rate. The SRO can be offset by increases in certain jurisdictional costs. The SRO has not been used with the Modified Fixed Variable classification method.
Sales, Interdepartmental
Sales to other departments of a company (gas, electric, steam, water, etc.) and dollar value of such sales if the charges are at tariff or other specified rates for the energy supplied.
Sales/Transportation Service
Under traditional sales service agreements, transmission and distribution companies purchase gas from suppliers, transport the gas to customers and sell it to them. Under transportation service agreements, transmission and distribution companies transport gas supplies for customers who have purchased the gas directly from other parties.
Salt Cavern
An underground natural gas storage cavern which has been developed in a salt dome by the solution mining process.
Salvage (Proceeds)
The value realized from plant removed or otherwise disposed. This value may be in the form of cash, debits to the materials and supplies accounts, trade-in allowance, or other consideration.
Salvage Value
The amount received for property retired, less any expenses incurred in connection with the sale or in preparing the property for sale; or, if retained, the amount at which the material recoverable is chargeable to Materials and Supplies, or other appropriate account.
Salvage, Net
The difference between value of salvage and cost of removal resulting from the removal, abandonment, or other disposition of plant. Positive net salvage results when salvage value exceeds removal costs. Negative net salvage results when removal costs exceed salvage value. Positive net salvage decreases the cost to be recovered through depreciation expense, and negative net salvage increases it.
Satellite LNG Facility
A facility for storing and vaporizing LNG to meet relatively modest demands at remote locations or to meet short-term peak demands. LNG is usually trucked to such facilities.
Saturated Air
Air containing all the water vapor it can hold at its temperature and pressure.
Saturation, Appliance or Customer
The number of specified appliances or users divided by the basic units or total potential of the universe involved, i.e., Gas Heating Saturation related to customers is the total number of customers with space heating divided by the total number of customers. Saturation should not be used alone but should be associated with customers, families, households, population, or other qualifying terms indicating the universe referred to. For industry statistics, saturation based on customers served is used.
Schedule
A pipe size system (outside diameters and wall thickness) originated by the iron pipe industry.
Scheduling
A process by which nominations are first consolidated by receipt point, by contract, and verified with upstream/ downstream parties. If the verified capacity is greater than or equal to the total nominated quantities, all nominated quantities are scheduled. If verified capacity is less than nominated quantities, nominated quantities will be allocated according to scheduling priorities.
Scheduling Penalty
A monthly or daily penalty assessed on the difference between the volume scheduled to be tendered by the shipper to the pipeline and the volume actually tendered for delivery. The purpose of the penalty is to maintain high throughput on the pipeline and prevent disruption of deliveries to other transportation and sales customers. Because the damage caused by the shipper failing to tender scheduled volumes cannot be remedied after the fact, there is no notice or make-up period involved.
Schematic
An outline, systematic arrangement, diagram, scheme, or plan. An orderly combination of events, persons, or things according to a definite plan. A diagram showing the relative position and/or function of different components or elements of an object or system.
Schlumberger
Refers to electric well logging. It is derived from the name of a French scientist who first developed well logging.
Scraper
A device used to clean deposits of paraffin or other foreign substances from tubing or flow lines. See PIG and RABBIT.
Scraper Trap
A fitting in either end of a pipeline with a shut-off valve and a door to insert or remove a pipeline scraper which is pushed through the pipeline to clean it and increase flow efficiency.
Scrub
To remove certain constituents of a gas by passing it through equipment (Scrubber) in which the gas is intimately mixed with a suitable liquid that absorbs or washes out the constituent to be removed from the gas.
Scrubber, Rotary
A piece of equipment for removing impurities from gas by passing the gas over rotating surfaces or brushes that are partially immersed in liquid.
Scrubber, Tower
A vertical vessel filled with plates or suitable packing over which scrubbing liquid flows upward through the liquid, separating entrained liquids or solids from the gas.
Seaboard Method
A classification method that allocates fixed costs equally between the demand and commodity components of the rate.
Sealed Burners
Gas burners that are sealed to prevent spillovers from reaching the burner box.
Seasonal Curtailment
Curtailment imposed on a seasonal summer (April-October) or winter (November-March) basis because of gas supply deficiency. See PEAK DAY CURTAILMENT.
Seasonal Gas
Seasonal gas is gas sold during certain periods of the year. It may be sold either on a firm or on an interruptible basis.
Seasonal Method
An allocation method which allocates demand and/or commodity costs to customer classes by seasonal usage.
Secondary Air
The air for combustion externally supplied to the flame at the point of combustion.
Secondary Gas Cap
A gas cap to an oil reservoir, not present at the time of discovery of the reservoir, that results from the release of gas from solution within the reservoir oil as the reservoir pressure declines, and its subsequent migration to the top of the reservoir due to the force of gravity,
Secondary Measure Adoption
Any conservation or energy efficiency measures that a customer adopts outside of a DSM program as a direct result of that program.
Secondary Production or Recovery
Oil and gas obtained by the augmentation of reservoir energy; often by the injection of air, gas, or water into a production information. See REPRESSURING.
Section 311 Transportation
Refers to transportation pursuant to Section 311 of the NGPA, which authorizes interstate pipelines to transport "on behalf of" local distribution companies or intrastate pipelines without the necessity of obtaining a certificate under Section 7 of the NGA.
Seepage (Or Weeping)
Failure that occurs through essentially microscopic breaks in the pipewall, frequently only at or near the test pressure.
Seismograph
A device for detecting vibrations in the earth. It is used in prospecting for probable oil or gas bearing structures. In this application, the vibrations are created by discharging explosives in shallow bore holes. The nature and velocity of the vibrations as recorded by the seismograph indicate the general nature of the section of earth through which the vibrations pass.
Selective Catalytic Reduction
A post combustion control which taps flue gas off the boiler and injects ammonia with nitrogen oxide gas to reduce emissions.
Self-Help Program
A program promulgated by the FPC during the interstate natural gas shortage of the 1970s whereby industrial users could purchase natural gas directly from producers and utilize the natural gas pipelines as contract carriers to transport the gas. As end-users, self-help industrial users were not restricted by federal wellhead price ceilings (since the gas was not sold for resale) and thus could compete with intrastate pipelines for natural gas.
Seller
A legal entity who has contractual signatory authority and warranty of title to sell natural gas services, natural gas or its by-products as a commodity. The seller may have legal authority to sell as agent for or on behalf of other owners.
Semiautomatic Valve
A valve that is opened manually and closed automatically or vice versa.
Sendout Curve
Sendout plotted as a function of temperature.
Sendout, Gas
Total gas produced, purchased (including exchange gas receipts), or net withdrawn from underground storage within a specified time interval, measured at the point(s) of production and/or purchase, and/or withdrawal, adjusted for changes in local storage quantity. It comprises gas sales, exchange, deliveries, gas used by company, and unaccounted for gas. Expressed in various units such as therms, Btu, cubic feet, etc.
Sendout, Maximum Day
The greatest actual total gas sendout occurring in a specified 24-hour period. Compare DESIGN DAY; PEAK DAY.
Sendout, Minimum Day
The smallest actual total gas sendout occurring in a specified 24-hour period.
Separator
A piece of equipment for separating one substance from another when they are intimately mixed, such as removing oil from water, oil from gas, ash from flue gas, or tramp iron from coal.
Service (Service Line, Service Pipe)
The pipe which carries gas from the main to the customer's meter. Compare CLASS OF SERVICE.
Service Area
A geographic area where a utility provides service, usually under provisions of a franchise, charter or certificate, and subject to special government regulations. See PUBLIC UTILITY.
Service Charge
The fee charged a customer by a utility for work on the customer's premises. Also, part of a rate schedule, such as a customer charge; generally does not include any gas.
Service Drip
A liquid-collecting trap at the low point in a customer's gas service piping when the piping cannot be sloped back to the distribution main. Compare DRIP.
Service Factor
A factor which is used to reduce a strength value to obtain an engineering design stress. The factor may vary depending on the service conditions, the hazard, the length of service desired, the uncertainties, and the properties of the pipe.
Service Life
The time between the date plant is includible in plant in service, or plant leased to others, and the date of its retirement. If depreciation is accounted for on a production basis rather than on a time basis, then service life should be measured in terms of the appropriate unit of production.
Service Pipe
See SERVICE.
Service Pressure, Standard
The gas pressure that a utility undertakes to maintain on its domestic customers' meters. (Sometimes called the normal utilization pressure).
Service Riser
A vertical pipe, either inside or outside a foundation wall, from the grade of the service pipe to the level of the meter.
Service Shutoff
This may refer either to a service stop or to a meter stop used to cut off the supply of gas.
Service Stop
The plug-type valve located in the service line between the main and the building; however, it is often used synonymously with the meter stop which is located within the building or immediately before the meter or regulator in outside settings. Compare VALVE, SHUTOFF.
Service Stub
A piece of pipe connected to a main and usually extended to the curb line for the addition of a service.
Service Tee
A tee is a customer's service piping with one leg closed and used for access to the service pipe in case of plugging with solids. Also, a tee used for making a hot tap on a main to supply a service.
Service Territory
See SERVICE AREA.
Service Value
The difference between original cost and net salvage value of utility plant.
Service, No-Notice
A service which permits the delivery of gas without prior notification.
Service, Standby
Service through a permanent connection not normally used but available in lieu of, or as a supplement to, the usual source of supply.
Set Casing
To install steel pipe or casing in a well bore. An accompanying operation is the cementing of the casing in place by surrounding it with a wall of cement extending for all or part of the depth of the well.
Settlement Conference
An informal meeting of interested parties to resolve differences in a rate case. It is scheduled after Staff TOP sheets are published. See TOP SHEETS.
Settlement Rates
Rates accepted by the interested parties which are effective retroactively to the end of the five month suspension period on order of the FERC.
Sewage Gas
A gas produced by the fermentation of sewage sludge low in heating value due to dilution with CO2 and N2; also marsh gas or firedamp.
Shale Oil
A liquid similar to conventional crude oil but obtained from oil shale by conversion of organic matter (kerogen) in oil shale.
Shift Converter
A reactor which catalytically converts carbon monoxide and water into hydrogen and carbon dioxide.
Shipper
Owner of the transportation contract, for whom gas is transported.
Shooting
Exploding nitroglycerine or other high explosives in a hole to shatter the rock and increase the flow of oil. Same as torpedoing. Also, in seismograph work, this refers to the discharge of explosives to create vibrations in the earth's crust. See SEISMOGRAPH.
Shooting Rights
Permission to conduct geological and geophysical activity only, without the option to acquire lease acreage.
Short Form Certificate Application
A statement, in lieu of a conventional certificate application, that may be filed by independent producers annually transporting or selling less than 1,000,000 Mcf of natural gas that is subject to the jurisdiction of the Commission.
Short Form Rate Schedule
A statement, in lieu of a conventional rate schedule, that may be filed by independent producers annually transporting or selling less than 100,000 Mcf of natural gas that is subject to the jurisdiction of the Commission.
Short Term Sale
Any short term purchase covering a period of two years or less. Purchases from intrastate pipelines pursuant to Section 311(b) of the NGPA of 1978 are classified as short term sales regardless of the stated contract term.
Show Cause Order
See ORDER TO SHOW CAUSE.
Shrinkage, Natural Gas
The reduction in volume of wet natural gas due to the extraction of some of its constituents, such as hydrocarbon products, hydrogen sulphide, carbon dioxide, nitrogen, helium, and water vapor.
Shut-In
Shut off so there is no flow; refers to a well, plant, pump, etc., when valves are closed at both inlet and outlet.
Shut-In Royalties
Amounts paid to lessors as compensation for loss of income from non-production of producible reserves.
Shut-In Well
A well that has been completed but is not producing. A well may be shut-in for tests, repairs, or to await construction of gathering lines.
Side Tracking
Drilling past a broken drill or casing which has become permanently lodged in the hole. This operation is usually accomplished by use of a special tool known as a whip-stock.
Side Wall Coring
The taking of geological samples of the formation which constitutes the wall of the well bore. Another term in general use for this operation is "side wall sampling".
Silica Gel
A desiccant, hygroscopic material that readily absorbs substantial quantities of moisture and is used to reduce the relative humidity of air or gas.
Skidding the Rig
Moving a rig from the location of a lost or completed hole preparatory to starting a new one. In skidding the rig, the move is accomplished with little or no dismantling of equipment.
Sleeve
A piece of pipe or thimble for covering another pipe or joint or for coupling two lengths of piping.
Slug the Pipe
Before hoisting drill pipe, it is desirable to pump into the top section of it a quantity of very heavy mud which will cause the level of the fluid in the pipe to fall. When a stand of pipe is unscrewed, the drilling fluid will have been evacuated from it. This prevents crew members and tools from becoming covered with the drilling fluid.
Snapback Effect
See REBOUND EFFECT.
Solar Radiation
The total electromagnetic radiation emitted by the sun.
Solar System, Active
A system that uses natural convective currents or other nonmechanical means for collecting, storing, and distributing solar energy.
Solution
Mixture in which the components lose their identity and are uniformly dispersed. All solutions are composed of a solvent (water or other fluid) and the substance dissolved called the "solute". A true solution is homogeneous, as salt in water. Air is a solution of oxygen and nitrogen.
Solvent Cementing
Joining pipe by the use of a solvent which dissolves the surface of the pipe and forms a continuous bond upon evaporation.
Sorbent
A material which extracts one or more substances present in an atmosphere or mixture of gases or liquids with which it is in contact due to an affinity for such substances.
Sound Attenuation
A reduction in the sound level.
Sour Gas
Gas having a high sulphur content.
South Georgia Method
Method which bridges the gap between the Commission's past flow-through policies of book and tax timing differences to the Commission's current policy of tax normalization as expressed in the Commission's Order No.144. The first step in developing the "South Georgia Method" is to reconcile the book depreciable plant to the tax depreciable plant. The reconciliation determines the amount of excess tax depreciation claimed over time due to liberalized tax methods in comparison to book depreciation. The excess tax depreciation over book depreciation times the statutory Federal income tax rate determines the deficiency in the Deferred Tax Account, Account No. 282. The deficiency is amortized over the remaining book depreciable life. Once the deficiency is fully amortized, the deferred tax account will be fully funded.
Space Heater
See HEATER, ROOM.
Special Marketing Programs
See RATE DESIGN.
Specific Gravity
The ratio of the density of a substance to the density of a reference substance, both at specified physical conditions. As applied to gas, air is the reference substance. Two specific gravity definitions are recognized in gas measurement: 1. Real Specific Gravity. The density ratio between a gas and air determined by measurement at the same temperature and pressure. 2. Ideal Specific Gravity. The ratio of the molecular weight of a gas to the molecular weight of air. (Mol. wt. of air = 28.9644).
Specific Heat
The heat required to raise a unit mass of a substance through a degree of temperature difference. Also, the ratio of the thermal capacity of a substance to that of water. The specific heat of fluids varies with temperature and pressure.
Specific Weight
The weight of a unit volume, usually expressed as pounds weight per cubic foot.
Spillover Effects
Reductions in energy consumption in a utility's service territory caused by the presence of DSM programs, beyond program-induced savings of the participants.
Spillpoint
See STORAGE, UNDERGROUND.
Split System
Historically, a combination of warm-air heating and radiator heating; the term is also used for other combinations such as hot water-steam, steam-warm air, as well as gas heat-electric cooling.
Sponge
A mixture of iron oxide and wood shavings for the removal of hydrogen sulfide from gas.
Spot Market
A market characterized by short-term, interruptible (or best efforts) contracts for specified volumes of gas. Participants may be any of the elements of the gas industry - producer, transporter, distributor, or end user. Brokers may also be utilized.
Spot Price
Current one-time purchase price.
Spot Purchase
Short term sale of gas to an end-user, LDC, or pipeline for which the duration varies.
Spray Pond
Arrangement for lowering the temperature of water by evaporative cooling of the water in contact with outside air; the water to be cooled is sprayed by nozzles into the space above a body of previously cooled water and allowed to fall into it.
Spud
The small cap or plug, with an orifice through it, that admits gas into the mixing chamber of a burner. See ORIFICE PLUG.
Spudding
Refers to the act of hoisting the drill pipe and permitting it to fall freely so that the drill bit strikes the bottom of the well bore with considerable force. This is done to clean the bit of an accumulation of the sticky shale which has slowed down the rate of penetration. Careless execution of this operation can result in kinks in the drill pipe and damaged bits.
Spudding In
The very beginning of drilling operations of a well. The term has been handed down from cable tool operations in the early days of the oil industry.
Square Foot of Radiation
The amount of heating surface in the form of radiators, convertors, unit heaters, or other devices which will emit 240 Btu per hour.
Stabbing Board
A temporary platform erected in the derrick at an elevation of about 20 to 40 feet above the derrick floor. The derrickman or other crew members work on this board while casing is being run in a well. Derived from the term "to stab" meaning to guide a joint while it is being screwed into another joint or section.
Stabilization
Stabilization is the addition of a gas to the gas normally supplied for the purpose of adjusting the heat content to a specified value. Air is often used for the purpose of reducing heat content and LP gases are used for the purpose of enriching or raising the heat content.
Stabilizer
An ingredient used in the formulation of some plastics, to assist in maintaining the physical and chemical properties of the compounded materials at their initial values throughout the processing and service life of the material.
Stack
A chimney or conduit for smoke.
Stack Effect
The tendency of a heated gas to rise in a vertical passage as in a chimney, small enclosure, or stairwell.
Stack Gases
See GAS, FLUE.
Stack Loss
The flue gas loss; the sensible and latent heat lost up the chimney in the flue gas.
Staff
Employees, other than the Commissioners and their staffs and the ALJs and their staff, of the FERC.
Staff Audit
Staff review of company's rate filing, usually within 60 days of the filings suspension order. See SUSPENSION ORDER, TOP SHEETS.
Standard & Poor's
Rating
Standard Dimension Ratio (SDR)
The ratio of diameter to wall thickness of pipe. Each SDR category has the same pressure rating. One SDR series is based on inside diameters and another on outside diameters. Normally used with plastic pipe.
Standard Industrial Classification Manual (SIC)
A book prepared and issued by the Office of Statistical Standards, United States Bureau of the Budget, to enable classification of business establishments by the type of activity in which engaged.
Standard Metering Base
Standard conditions, plus agreed corrections, to which gas volume are corrected for purposes of comparison and payment.
Standby Charge
A charge related to STANDBY SALES SERVICE. The charge is designed to recover only the fixed costs incurred by the pipeline which are associated with its ability to stand ready to provide sales service. Such fixed costs are generally recovered through the pipeline's sales commodity rate. As such, the pipeline would not be able to recover those costs should the customer chose, instead, to use its capacity for transportation.
Standby Loss, Water Heater
The percentage of total energy stored in water which is lost each hour from a storage-type water heater.
Standby Sales Service
A service which permits a sales customer the option, on any day, of using up to a set percentage of its daily contract demand for transportation, rather than sales service. In return for this ability to "swing", the customer is assessed a STANDBY CHARGE. Trans-portation under Standby Sales Service is generally provided under the terms of the pipeline's Firm Trans-portation rate schedule.
Standpipe
A vertical pipe or reservoir for water used to secure a uniform pressure.
Start Cart
A heating device which supplies load pressure steam for fuel cell heat up.
Static Pressure
The force exerted per unit area by a gas or liquid, measured at right angles to the direction of flow, or the pressure when no liquid is flowing.
Station Meter
A meter of high capacity for measuring the output of a gas plant or pipeline delivery station.
Station, Pressure Regulating
See PRESSURE REGULATING STATION.
Steam Tracing
A graphic recording of steam pressure and temperature done instrumentally.
Steam Trap
A device for allowing the passage of condensate or air and condensate and preventing the passage of steam.
Steam Turbine
A type of motive equipment powered by steam used to drive mechanical apparatus. It has a rotary motion in contrast to a reciprocating motion.
Steam, Exhaust
Generally, water vapor which has had most of the usable energy removed.
Steam, Live
Water vapor which includes recoverable energy.
Steam, Saturated
Steam at a temperature and pressure such that any lowering of the temperature or increase in pressure will cause condensation.
Steam, Super-Heated
Water vapor heated beyond the point at which complete vaporization occurs (100% quality).
Stipulation and Agreement (S&A)
A document prepared to express in writing the agreement of the parties to a controversial matter such as a rate case. A Stipulation and Agreement settling all or part of a rate case must be submitted to the Commission for approval. See CONSENTING PARTY, CONTESTING PARTY.
Storage Cycle
See STORAGE, UNDERGROUND.
Storage Horizon
See STORAGE, UNDERGROUND.
Storage Mains
Those mains used primarily for injection and withdrawal of gas to and from underground storage.
Storage Rights
See STORAGE, UNDERGROUND.
Storage Zone
See STORAGE, UNDERGROUND.
Storage, Buried Pipe (Bottle-Type Holder)
A system of storage in especially designed high pressure pipe sections or bottles capable of storing natural gas at pressures near or equal to the pressure of maximum super-compressibility. Not storage in ordinary steel pipe.
Storage, Contract
See CONTRACT STORAGE.
Storage, Local
The storage facilities, other than underground storage, that are an integral part of a distribution system, i.e., on the distribution side of the city gate, whether for manufactured, mixed, natural, liquefied petroleum or liquefied natural gases.
Storage, Underground
The utilization of subsurface facilities for storing gas which has been transferred from its original location for the primary purposes of load balancing. The facilities are usually natural geological reservoirs such as depleted oil or gas fields or water-bearing sands sealed on the top by an impermeable cap rock. The facilities may be man-made or natural caverns.
Storage, Underground - Aquifer Storage.
The storage of gas underground in porous and permeable rock stratum, the pore space of which was originally filled with water and in which the stored gas is confined by suitable structure, permeability barriers, and hydrostatic water pressure.
Storage, Underground - Base Gas.
(Also called cushion gas). The total volume of gas which will maintain the required rate of deliver during an output cycle.
Storage, Underground - Current Gas.
The total volume of gas in a storage reservoir which is in excess of the base gas. Also called Working Gas.
Storage, Underground - Current Reservoir Capacity.
The total volume of gas which a storage reservoir can contain within the present design capacity.
Storage, Underground - Deliverability.
The capability of a storage reservoir to deliver gas, expressed in Mcf/day at a given flowing wellhead pressure.
Storage, Underground - Extraneous Gas.
See STORED GAS, this section.
Storage, Underground - Foreign Gas.
See STORED GAS, this section.
Storage, Underground - Injectability.
The capability of a storage reservoir to accept gas, expressed in Mcf/day at a given pressure condition.
Storage, Underground - Injected Gas.
See STORED GAS, this section.
Storage, Underground - Input Well.
A well utilized for injection of gas.
Storage, Underground - Maximum Gas in Storage.
The highest volumetric balance of total gas in storage during any storage cycle.
Storage, Underground - Native Base Gas.
That part of the volume of cushion gas which is indigenous to the storage reservoir.
Storage, Underground - Native Gas.
The volume of gas indigenous to the storage reservoir.
Storage, Underground - Observation Well.
A cased bore hole extending from the surface to any horizon which is used to obtain information relating to storage operations.
Storage, Underground - Output Well.
A well utilized for withdrawal of gas.
Storage, Underground - Overburden.
All sediments of rock that cover or overlie the reservoir rock.
Storage, Underground - Overpressuring.
The technique of increasing the maximum pressure in a natural gas storage reservoir above the discovery pressure.
Storage, Underground - Spillpoint.
An area of minimum structural closure where gas or fluids may escape or be forced out of the reservoir structure.
Storage, Underground - Storage Cycle.
A period commencing with an injection phase during which gas is stored and ending with a subsequent withdrawal phase during which gas is removed.
Storage, Underground - Storage Horizon.
See STORAGE ZONE, this section.
Storage, Underground - Storage Reservoir.
That part of the storage zone having a defined limit of porosity and/or permeability which can effectively accept, retain, and deliver gas.
Storage, Underground - Storage Rights.
The right to store gas in a reservoir by leasing, renting, or purchasing the gas rights and surface well location from the free-title landowner, the surface-rights owner, and the mineral-rights owner.
Storage, Underground - Storage Well.
A cased bore hole, extending from the surface into the storage zone, which is used for gas input and/or output purposes.
Storage, Underground - Storage Zone.
The geological name of that stratum in the earth's crust within which the storage reservoir is located.
Storage, Underground - Stored Gas.
Gas physically injected into a storage reservoir.
Storage, Underground - Top Storage Capacity.
Working gas capacity.
Storage, Underground - Top Storage Gas.
See WORKING GAS, this section.
Storage, Underground - Total Input Gas.
The volume of extraneous gas injected into a storage reservoir during a given period of time.
Storage, Underground - Total Output Gas.
The volume of gas withdrawn from a storage reservoir during a given period of time.
Storage, Underground - Ultimate Reservoir Capacity
The total estimated volume of gas that could be contained in storage reservoir when it is developed to the maximum design pressure.
Storage, Underground - Ultimate Reservoir Pressure
The maximum reservoir pressure permitted by the geological configuration of the reservoir.
Storage, Underground - Withdrawn Gas.
Gas taken out of storage.
Storage, Underground - Working Gas.
Gas in an underground storage field that is available for market. May also be called Current Gas.
Stored Gas
See STORAGE, UNDERGROUND.
Straddle Point
A gas plant constructed near a transmission company pipeline downstream from the fields where the gas is produced, also referred to as "on-line" plants. The gas is sold at the lease/field to the transmission company. The producer and/or plant owner(s) retain processing rights and reimburse the transmission company for the plant thermal reduction (PTR) either in cash or in additional gas deliveries.
Straight Fixed Variable
See RATE DESIGN.
Straight Gas Utility
Company which derives the major portion of its total operating revenue from gas operations. For purposes of A.G.A. statistics, a straight gas utility derives at least 95 percent of its total operating revenues from gas operations.
Straightening Vanes
Round, square, or other shaped tubing installed axially inside the piping preceding an orifice or turbine meter to eliminate swirls and cross-currents set up by the pipe fittings and valves. This considerably reduces the amount of straight pipe required preceding the measuring element.
Strain
The ratio of the elongation to the gauge length of the test specimen, that is, the change per unit of original length. It is expressed as a dimensionless ratio.
Strapping
A method of checking a bell prover by determining the relation between displaced volume and linear movement of a bell prover by means of measuring scale length, bell circumference, and displacement of the sealing liquid.
Strategic Conservation
Utility-stimulated programs directed at reducing end-use consumption in specific (usually peak) periods.
Strategic Load Growth
A targeted increase in end-use consumption during certain time periods or among certain customer types. The result is a general increase in energy sales beyond the valley filling strategy. Strategic load growth may involve increased market share of loads that are, or can be, served by competing fuels, as well as area development.
Stray Current
Electrical current (normally DC) from either natural or man-caused source, which could result in corrosion if not drained properly or compensated for by other means.
Street Ell
An L-shaped pipe fitting with external threads on one end and internal threads on the other end. Compare ELL.
Street Tee
A tee with an external thread on one of the run connections and with internal threads on the opposite run connection and on the side outlet.
Strength
The stress required to break, rupture or cause a failure.
Stress
The resultant force that resists change in the size or shape of a body acted on by external or internal forces. "Stress" is often used as being synonymous with unit stress which is the stress per unit area (psi).
Stress Crack
Internal or external crack in a material caused by tensile or shear stresses less than that normally required for mechanical failure in air. The development of such cracks is frequently related to and accelerated by the environment to which the material is exposed. More often than not, the environment does not visibly attach, soften, or dissolve the surface. The stresses may be internal, external, or a combination of both.
Stress Relaxation
The decrease of stress with respect to time in a piece of plastic that is subject to an external load at constant deformation.
Stress-Rupture Test
Method of testing plastic pipe to determine the hydrostatic strength by applying a constant internal pressure and observing time to failure.
Stringing-Up
The act of threading the drilling line through the sheaves of the traveling block and the crown block. One end of the line is secured to the hoisting drum and the other anchored to the derrick substructure.
Strip
To remove light hydrocarbon fractions from gas for recovery and sale.
Stripper
A pressure vessel in which the carbon dioxide and heavy hydrocarbons are stripped from the liquid methanol by passing a clean stream of methane up through the methanol.
Sub
A short piece of pipe used to connect parts of the drilling string that could not otherwise be connected due to differences in thread size or design.
Subbituminous Coal
Ranking of soft coal generally having a heating value of 8,300-13,000 Btu's/lb -- high volatile matter and ash.
Subcooling
In the cryogenic area, e.g. LNG, subcooling is the cooling of liquid to below its saturation temperature for the pressure under consideration. In practice, subcooling has the effect of reducing boil-off in LNG storage and transportation.
Subject to Refund
A condition attached by the FERC on revised rates, after the suspension period has expired, denoting that a company is allowed to charge and collect such rates provided, however, that appropriate rate refunds and reductions, including interest, may be required upon resolution of the rate proceeding if such rates are found to be in excess of just and reasonable rates. Under certain conditions rates may go into effect subject to refund without suspension.
Submetering
The practice of remetering purchased energy beyond the customer's utility meter, generally for distribution to building tenants through privately owned or rented meters.
Subscription Rights
A privilege to the stockholders of a corporation to purchase proportionate amounts of a new issue of securities at an established price, usually below the current market price; also, the negotiable certificate or warrant evidencing such privilege.
Substitute Natural Gas (SNG)
A gas manufactured from carbonaceous material whose characteristics are substantially interchangeable with natural gas. The resultant gas is composed primarily of methane. At this writing, SNG feedstocks are the llight hydrocarbons, propane, butane, and the naphthas. Development is underway of processes for production from heavier feedstocks, coal, peat, and solid wastes. See SYNTHETIC NATURAL GAS.
Successor Contract
Any contract, other than a rollover contract, entered into on or after the date of enactment of the NGPA of 1978, for the first sale of natural gas that was previously subject to an existing contract, whether or not there is an identity of parties or terms with those of the previously existing contract.
Sulfides (Organic)
A group of organic compounds containing a sulfur atom that is directly bonded between two carbon atoms. Some of the organic sulfides, such as dimethyl sulfide and thiophene, are considered to be suitable odorants.
Summer Valley
The depression that occurs in the summer months in the daily load of a gas distribution system of pipeline.
Supercharging
A method used to increase the pressure, and thereby the amount of charge per cycle, above that of a normally aspirated internal combustion engine; it permits more fuel to be burned and is a practical means to greater engine power.
Supercompressibility Factor
A factor used to account for the following effect: Boyle's law for gases states that the specific weight of a gas is directly proportional to the absolute pressure, the temperature remaining constant. All gases deviate from this law by varying amounts, and within the range of conditions ordinarily encountered in the natural gas industry, the actual specific weight under the higher pressure is usually greater than the theoretical. The factor used to reflect this deviation from the ideal gas law in gas measurement with an orifice meter is called the "supercompressibility factor Fpv". The factor is used to calculate actual volumes from volumes at standard temperatures and pressures from actual volumes. The factor is of increasing importance at high pressures and low temperatures.
Superseding Rate Schedule
A contract submitted as a rate schedule to replace an existing rate schedule. When a producer and purchaser have entered into a new contract to cover a sale being made under an existing rate schedule, the new contract is usually designated as a "superseding rate schedule" and assigned a new rate schedule number.
Superseding Tariff Sheets
Revised tariff sheets filed with the Commission to update or modify original or previously revised tariff sheets currently on file in a pipeline's FERC Gas Tariff. If the revised tariff sheets are accepted for filing by the Commission, they become effective on the date specified in the Commission's order, at which time they supersede the currently effective tariff sheets.
Supplemental Gas
Any SNG, propane-air mixtures, refinery gas, biomass gas, air injected to reduce heat content, or manufactured gas that is mixed and distributed with natural gas.
Surcharge Adjustment
A pricing mechanism of a PGA to administer prior period over/under recoveries of gas costs in the current period.
Surface Pipe
The first string of casing to be set in a well. The length will vary in different areas from a few hundred feet to three or four thousand feet. Some states require a minimum length to protect fresh-water sands. On some wells, it is necessary to set a temporary conductor pipe which should not be confused with surface pipe as described here.
Survivor Curve
A graphical presentation of survivors at the beginning of each of a consecutive series of age intervals. The area under a complete curve represents the total dollar years or unit years of service. A stub survivor curve is one which does not extend to zero survivors. The curve is plotted from the observed life table.
Survivors
The plant surviving at the beginning of an age of interval and exposed to the risk of retirement during that interval.
Suspension Order
FERC Order suspending the effectiveness of a new rate case for an additional five months beyond the pipeline's 30 day request.
Sustained Pressure Test
A constant internal pressure test for an extended period of time. One thousand hours is a commonly used period.
Sweet Gas
Natural gas not contaminated by corrosion inducing impurities such as hydrogen sulfide, or with a low level of impurities.
Swing Connection
The combination of fittings that will swing up, down, or sideways slightly for aligning pipe and for absorbing movement or strain.
Swivel, Meter
The fitting that connects to the inlet and the outlet of a small gas meter.
Syncrude
Synthetic crude oil derived from coal or oil shale.
Synthesis Gas
A mixture of carbon monoxide and hydrogen frequently used to produce (synthesize) many chemicals depending on the reacting conditions and catalysts used. Examples are methanol, methane, acetic acid, ammonia, and numerous other chemicals.
Synthetic Natural Gas
A descriptive term used interchangeably with SNG and Substitute Natural Gas. It is a gas manufactured from naphtha , coal, etc., and is substituted for, or mixed with, natural gas by a pipeline or gas distribution utility.
System Capacity
The amount of gas that can be transported under specified conditions of pressure, temperature and loading (generally peak day requirements). Note that the maximum amount of gas that can be delivered during any period time may vary depending upon the amount of line pack, pressure differential, points of receipt and delivery, gas gravity and temperature conditions at the beginning of the period. Consequently, a system's capacity will vary from time to time depending upon existing conditions.
System Sendout
Total volume of gas delivered from the system in a specified period of time -- day, month, year.
System Storage
Storage facilities, or portion of storage facilities, which is used by the pipeline to store gas for its own use, to meet the peak day requirements of its sales customers and to provide flexibility on its system. See CONTRACT STORAGE.
System Supply
Purchases of natural gas for the purchaser's own system supply requirements (i.e., for resale by the purchaser).
System Type - Distribution.
Generally mains, services, and equipment which carry or control the supply of gas from the point of local supply to and including the sales meters. The system operates at various pressures as indicated below. a. High Pressure. A system which operates at a pressure higher than the standard service pressure delivered to the customer; thus, a pressure regulator is required on each service to control pressure delivered to the customer. Sometimes this is referred to as medium pressure. b. Low Pressure or Utilization Pressure. A system in which the gas pressure in the mains and service lines is substantially the same as that delivered to the customers' appliances; ordinarily a pressure regulator is not required on individual service lines.
System Type - Field and Gathering.
A network of pipelines (mains) transporting natural gas from individual wells to compressor station, processing point, or main trunk pipeline.
System Type - Main.
The network of distribution piping to which customers' service lines are attached. Generally, large pipes are laid in principal streets with smaller laterals extending along side streets and connected at their ends to form a grid; sometimes laterals are brought to dead ends. Compare with DISTRIBUTION, this section.
System Type - Transmission.
Pipelines (mains) installed for the purpose of transmitting gas from a source or sources of supply to one or more distribution centers, to one or more large volume customers, or a pipeline installed to interconnect sources of supply. In typical cases, transmission lines differ from gas mains in that they operate at higher pressures, are longer, and the distance between connections is greater.
System-wide Cost
Produced by rolled-in pricing. Where one total cost, regardless of the individual costs, is used for ratemaking (e.g., PGA). See ROLLED-IN PRICING.
Systems, Burner, Type - High Pressure Air.
A system using the momentum of a jet of high pressure air (in excess of 5 psig) to entrain gas or air and gas to produce a combustible mixture.
Systems, Burner, Type - High Pressure Gas.
A system using the momentum of a jet of high pressure gas (in excess of 1/2 psig or 14 inches of water column) to entrain from the atmosphere all, or nearly all, of the air required for combustion.
Systems, Burner, Type - Low Pressure Air.
A system using the momentum of a jet of low pressure air (up to and including 5 psig) to entrain gas to produce a combustible mixture.
Systems, Burner, Type - Low Pressure Gas, or Atmospheric.
A system using the momentum of a jet of low pressure gas (up to and including 1/2 psig or 14 inches of water column) to entrain from the atmosphere a portion of the air required for combustion.
Systems, Burner, Type - Mechanical.
A system which proportions air and gas and mechanically compresses the mixture for combustion purposes.
Systems, Burner, Type - Suction.
A system applying a vacuum to a combustion chamber to draw in the air and/or gas necessary to produce the desired combustible mixture.
Systems, Burner, Type - Two-Valve.
A system using separate control of air and gas, both of which are under pressure. The valves controlling the air and gas flows may or may not be interlocked.

 
 

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