A measure of thermal resistance of a material, equal to the reciprocal of the U-Value. The R-Value is expressed in terms of degrees Fahrenheit times hours, times square feet per Btu.
A small plug that is run through a flow line by pressure to clean the line or test for obstructions. See PIG and SCRAPER.
A channel for holding wires, cables, or bus bars which is designed expressly for and used solely for this purpose. Raceways may be of metal or insulating material, and the term includes metal conduit, flexible metal conduit, and wireways.
The transmission of energy by means of electromagnetic waves. Radiant energy of any wave length may, when absorbed, become thermal energy and result in an increase in the temperature of the absorbing body.
Radiation Shield
A separate panel or panels interposed between heating surfaces and adjacent objects to reduce heat transmission by radiation.
Radiation, Infra-Red
The radiation in that portion of the electromagnetic spectrum between visible light and radio waves, originating from either incandescent or non-incandescent hot bodies or from flames. The energy is utilized as a means of direct heat transfer from the source to the object or objects to be heated without materially heating the intervening air.
A heating unit which transfers heat by radiation to objects within visible range and by conduction to the surrounding air which, in turn, is circulated by natural convection; a so-called radiator is also a convector, but the term radiator has been established by long usage.
Radiographic Inspection
Method used to determine flaws in pipe or other metals by use of a machine which emits X-rays or gamma rays which penetrate the metal and are transcribed onto film.
Range, Gas
Cooking stove. GAMA lists the following types: (1) Free-standing; (2) Set-in; (3) High Oven; (4) Built-in, Commercial; (5) Luncheonette and Restaurant; (6) Heavy Duty (Quality, Battery Type).
Ratio of maximum operating capacity to minimum operating capacity within a specified tolerance and operating condition.
Rankine Scale of Temperature
The absolute Fahrenheit scale. Degrees F + 459.67 = degrees R. (The factor is usually rounded to 460 for commercial usage).
Ratchet Clause, Demand
A clause in a rate schedule which provides that maximum past or future demands are taken into account to establish billings for previous or subsequent periods.
The unit charge or charges made to the customers for natural gas.
Rate Adjustment Provisions
A provision in a tariff which provides for changes in rates or total charges because of changes in specified items of cost, such as fuel price, purchased gas, tax, etc.
Rate Base
The investment value established by a regulatory authority upon which a utility is permitted to earn a specified rate of return. Generally, this represents the amount of property used and useful in public service and may include plant held for future use and may or may not include all or part of construction work in progress. If all or part of construction work in progress is included in rate base, there may or may not be an offset or partial offset to its return requirements due to the inclusion of an allowance for funds used during construction in net operating income. The investment included in rate base may be based on the following values or combinations thereof: fair value, prudent investment, reproduction cost, or original cost. The rate base may provide for the inclusion of working capital with positive allowances for cash-working capital, materials and supplies including fuel supplies and gas stored underground, bank balances, prepayments, and deductions for expense items such as property taxes and income taxes which are expensed currently but not paid until a later date. Rate base may also be adjusted to reflect customer payments for construction, company payments for advances, accumulated deferred income tax, and accumulated deferred investment tax credits to the extent the tax laws permit rate base adjustments. (Some jurisdictions reflect accumulated deferred tax balances as reductions to rate base while other jurisdictions reflect accumulated tax balances as zero cost money in the cost of capital determination).
Rate Case
A proceeding before a regulatory commission involving the rates to be charged for a public utility service.
Rate Design
The term "rate design" refers to the method of classifying fixed and variable costs between demand and commodity components. Examples of different rate designs are single rate (100% commodity or volumetric), two-part rates (demand and commodity rates), three-part rates (two demand and one commodity rate) and multiple rates (zone rates).
Rate Design - Modified Fixed Variable
The term "modified fixed variable rate design" refers to a method of determining demand and commodity rates whereby all fixed costs except equity return and related taxes are classified to the demand component.
Rate Design - Seaboard
The term "Seaboard rate design" refers to a method of determining demand and commodity rates whereby 50% of fixed costs are classified in the commodity component and 50% in the demand component.
Rate Design - Special Marketing Programs (SMP's)
SMP's involves the direct sale of producer gas that has previously been committed to a pipeline or distribution company. The gas is released by pipeline or another distribution company and the producer sells the released gas to an end-user or distribution company at a price below the original contract price in order to be competitive. Transportation of the gas is typically provided by the releasing pipeline at a rate which contributes to full fixed cost recovery. The FERC intends for the SMP to act as a mechanism for gas producers to make necessary price concessions in order to market their production.
Rate Design - Straight Fixed Variable
The term "straight fixed variable rate design" refers to a method of determining demand and commodity rates whereby all costs classified as fixed are assigned to the demand component.
Rate Design - Two Part Demand Rate
The term "two part demand rate" normally refers to a method of cost classification whereby a portion of cost classified as demand would be recovered based on peak day usage, and the remainder of costs classified as demand would be based on annual usage.
Rate Design - United
The term "United rate design" refers to a method of determining demand and commodity rates whereby 75% of fixed costs are classified in the commodity component and 25% in the demand component.
Rate of Flow
The volume or units of a material passing a given point in a system per unit of time.
Rate of Return
The return allowed to be earned (generally based on a cost of capital determination) or earned by a utility enterprise, generally calculated by dividing the net operating income (as defined) by the rate base.
Rate Schedule (Rates)
The commonly known forms of rates may be divided into two main classes, and each of these classes into several different types of rates.
Rate Schedule, Class
A rate schedule which is applicable to a specific customer class of service.
Rate Schedule, Cogeneration
A special rate to encourage commercial and industrial customers to use gas-fired cogeneration (generate their own electricity and use the waste heat from this process for thermal requirements).
Rate Schedule, Economic Development
A discount from standard commercial and industrial rates for takes above a minimum level for new or expanded service within an existing service area.
Rate Schedule, Flat
A rate schedule which provides for a fixed per unit charge regardless of the quantity of gas used.
Rate Schedule, Gas Cooling
A discount for using gas for air conditioning during the summer or off peak period.
Rate Schedule, Inverted
A rate schedule which provides different, but increasing, unit charges for various blocks of increasing demand or energy.
Rate Schedule, Lifeline
A rate structure applicable for residential customers which includes a specified block of energy use which is priced below the allocated cost of service. The block of energy may be priced at a flat amount for the entire block or on a per unit basis.
Rate Schedule, Natural Gas Vehicle (NGV)
A special rate for vehicles fueled with natural gas.
Rate Schedule, Straight Line
The term straight line indicates that the price charged per unit is constant and does not vary with increases or decreases in the number of units sold.
Rate Schedule, Transportation
A rate schedule to move someone else's gas on a transmission or distribution system. Most transmission companies have a number of transportation rate schedules based on mileage, zones, firm or interruptible, and so on.
Rate Schedule, Zone
A rate schedule restricted in its availability to a particular geographic area.
Rate Year
Begins when rates take effect (normally at the end of a suspension order). See SUSPENSION ORDER.
Rate Zones
Geographic areas of the Company's operations established to facilitate a design of rates to properly reflect the cost of serving customers in different parts of the company's system.
Rates, Demand
The term "demand rate" applies to any method of charge for gas service which is based upon, or is a function of, the rate of use or size of the customer's installation or maximum demand (in Mcf or therms) during a given period of time.
Rates, Demand - Block Hopkinson.
Either the demand charge, the commodity charge, or both, in a Hopkinson demand rate, may be the block form.
Rates, Demand - Flat.
The term "flat demand rate" applies to a charge for gas service based upon the customer's installation of gas-consuming devices. This is usually so much per Mcf, therm, month, or year. Sometimes this type of rate is nominally so much per fixture (as gas lamps) per year or month but estimated demand and quantity of gas likely to be used play an important part in the determination. Such a rate may be modified by the "block" or "step" methods.
Rates, Demand - Hopkinson.
The term "Hopkinson demand rate" applies to that method of charge which consists of a demand charge based upon demand (either estimated or measured) or connected load plus a commodity charge based upon the quantity of gas used.
Rates, Demand - Three Part or Three Charge.
Any of the foregoing types of rates may be modified by the addition of a customer charge. When such a charge is introduced in the Hopkinson demand rate, it becomes a "three part rate" or "three charge rate" which consists of a charge per customer or per meter plus demand and commodity charges.
Rates, Demand - Wright.
The term "Wright demand rate" applies to that method of charge which was the first to recognize load factor conditions. Under this rate, the consumer pays a different unit charge for each successive block of consumption. The consumer's maximum daily or hourly demand is a factor in the determination of the block size.
Rates, Inverted
Rate structure that divides consumption into continuous blocks. The larger the consumption block, the larger the associated price.
Rates, Meter
The term "meter rate" is applicable to any method of charge for gas service based solely upon quantity, such as Mcf or therms used. Declining Block. The term "block" indicates that a certain specified price per unit is charged for all units of gas taken within specified increments of use. Reduced prices per unit are charged for all or any part of succeeding blocks of such units, each such reduced price per unit applying only to a particular block or portion thereof. Inverted. The term "inverted" indicates that an increasing unit charge will be applied to succeeding blocks of increasing energy use. Step. The term "step" indicates that a certain specified price per unit is charged for all gas taken during a billing period, the rate, or price depending on the particular step within which the total consumption falls. Straight-Line (Flat). The term "straight-line" indicates that the price charged per unit is constant, i.e., does not vary on account of an increase or decrease in the number of units.
Rates, Mileage-Based
Rates designed to reflect the difference in pipeline costs based on the distance between supply sources and delivery points.
Ratification Agreement
A document whereby the producer and the purchaser adopt the terms and provisions of another contract as those under which they will make their own sale and purchase.
Limits placed on operating conditions of a machine, apparatus, or device based on its design characteristics.
Ratio of Specific Heats
For gases: The ratio of the specific heat at constant pressure to the specific heat at constant volume. This ratio is important in thermodynamic equations, and is given the symbol k where k=cp/cv. The ratio k lies between 1.2 and 1.4 for most gases.
Any material that causes a chemical reaction when added to a second substance.
Rebate Program
A DSM program in which the utility offers a financial incentive for the installation of energy-efficient equipment. Non-DSM rebate programs also exist, in which the utility offers an incentive for purposes of gaining market share of a specific end-use.
Rebound Effect
The incremental increase in demand that occurs when customers, by undertaking conservation actions, perceive a lower relative cost of energy, and therefore, purchase more in terms of comfort or
Receipt Point
Point at which transportation (movement) begins pursuant to the transportation contract. Generally, a producer's gas well, the outlet (tailgate) of a gas processing plant, or the delivery point (end) of a previous transportation contract.
Receiving Terminal
Coastal plant that accepts deliveries of liquefied natural gas and processes it back into gaseous form for injection into the pipeline system. Also known as REGASIFICATION TERMINAL.
Recoverable Heat
That portion of thermal input to a prime mover that is not converted to mechanical power and can be reclaimed for utilization.
Recovery Capacity, Water Heater
The quantity of water that a water heating system can heat from supply temperature to required temperature in one hour.
A device for converting alternating current to direct current, used in the gas industry for external corrosion control of pipe and other metals.
The repetition of a particular process; the return of a stream or part of a stream to a previous process or location for additional recovery of the desired components.
The delivery of natural gas by a pipeline to a shipper or for a shipper's account.
A pipe fitting which enables the connection of two pipes differing in diameter.
Refinery Gas
The reformer processes fuel used in the Fuel Cell Assembly. It takes a hydrocarbon fuel, such as natural gas, through a chemical transformation process in the presence of steam and a catalyst and dissociates the carbon and the hydrogen of the fuel into CO, CO2, and H2. A single cell of the assembly generates roughly one volt of DC and will create roughly 100-200 watts of electricity for each square foot of electrode cross-sectional area.
A chemical process using heat in presence of a catalyst to break down a substance into desired components, such as in the reforming of natural gas or light oils into lower Btu fuel gas.
Refractory Grate
The assembly within or upon which refractory material is supported.
A substance which will absorb heat while vaporizing and whose boiling point and other properties make it useful as a medium for refrigeration. (Chilled water, which by common acceptance is called a refrigerant, does not vaporize). See BRINE.
Refrigerating System, Absorption
A system whereby a secondary fluid absorbs the refrigerant, and in doing so, gives up heat, subsequently releasing the refrigerant, during which heat is absorbed.
Refrigerating System, Vapor-Compression
A refrigerating system in which the cooling effect results from expansion of a refrigerant after mechanical compression by either centrifugal or reciprocating compressors.
Refrigeration Capacity
The rate of heat removal by a refrigerating system, usually expressed in Btu per hour or in tons.
Refrigeration Cycle
The full sequence of condensation and evaporation. The heat of evaporation is obtained from the material to be cooled.
Refrigeration Ton
12,000 Btu per hour or 200 Btu per minute of heat removal. Originally, the amount of heat required to melt a ton of ice in 24 hours.
The retirement of one security issue with the proceeds received from the sale of another to provide for maturing debt or to take advantage of more favorable money market conditions.
Regasification Terminal
Regenerative Heating (Or Cooling)
Process of utilizing heat which must be rejected in one part of the cycle to perform a useful function in another part of the cycle.
Regenerator (SNG Plant)
A device which uses regenerative steam to reverse the absorption process. (For example, carbon dioxide is stripped from potassium bicarbonate which is formed in the absorption stage by regenerative steam, leaving regenerated potassium carbonate solution for reuse in the absorption stage).
Register, Heat/Cold
The grilled opening into a room by which the amount of warm air from a furnace or cold air from a cooling coil can be directed or controlled; it includes a damper assembly. See GRILLE.
The meter-dial positions of a meter index. The difference between two successive registrations indicates the volume of gas that has passed through the meter.
Regulator Vent
An atmospheric connection to the diaphragm of the regulator.
Regulator, Domestic Appliance Pressure
A device either adjustable or non-adjustable for controlling and maintaining a uniform outlet gas pressure. Spring Type, Adjustable - A regulator in which the regulating force acting upon the diaphragm is derived principally from a spring, the loading of which is adjustable. Spring Type, Nonadjustable - A regulator in which the regulating force acting upon the diaphragm is derived principally from a spring, the loading of which is not adjustable. Either of the above types may be further classified as follows: Main Burner Load Application - A regulator capable of controlling the flow of gas to main burners only. In such applications, the pilot is taken off upstream from the regulator. Main Burner and Pilot Load Application - A regulator capable of controlling the flow of gas to main and pilot burners. In such applications the pilot is taken off downstream from the regulator valve.
Regulator, Monitoring
A pressure regulator set in series with a control pressure regulator for the purpose of automatically taking over, in an emergency, the control of the pressure downstream of the station in case that pressure tends to exceed a set maximum.
Regulator, Pressure
A device that maintains the pressure in a fluid flow line, less than its inlet pressure within a constant band of pressures, regardless of the rate of flow in the line or the change in upstream pressure.
Regulator, Relief Pressure
A device for the purpose of relieving pressures in excess of a predetermined pressure.
Regulator, Service Pressure
A device designed to reduce and limit the gas pressure at the customer's meter.
Regulatory Adjustments
Company costs in the Base period that can not be included in the Cost of Service and are deleted.
Regulatory Lag
The time interval between when a charge or credit originates and when it becomes a part of the charge for service approved by the regulatory agency. Also, the inability to have rates adequately reflect the current level of operating costs or throughput. Rates generally reflect costs incurred in a historical test period.
Reinforced Plastic
A plastic with high strength fillers imbedded in the composition, in some mechanical properties superior to those of the base resin. The reinforcing fillers are usually fibers, fabrics, or mats made of fibers.
Relative Humidity
Release Gas
Gas previously contracted and dedicated between producers/brokers and a pipeline company which, through mutual agreement between the parties, was thereafter "released" from contract and ultimately made available for purchase by third parties.
Relief Opening
The opening provided in a draft hood to permit the ready escape to the atmosphere of the flue products from the draft hood in the event of no draft, back draft, or stoppage beyond the draft hood, and to permit inspiration of air into the draft hood in the event of a strong chimney updraft.
Relief Valve
Remaining Life
The expected future service life of plant at any given age.
Removal Costs
The costs of disposing of plant, whether by demolishing, dismantling, abandoning, sale, or other. Removal costs increase the amount to be recovered as depreciation expense.
Renewable Natural Gas (RNG) 
Pipeline compatible gaseous fuel derived from biogenic or other renewable sources that has lower lifecycle carbon dioxide equivalent (CO2e) emissions than geological natural gas. 
Replacing or Replacement
When not otherwise indicated in the context, means the construction or installation of plant in place of property retired, together with removal or abandonment of the property retired.
Forcing gas, under pressure, into the oil reservoir in an attempt to increase the recovery of crude oil; also done with water. See GAS CYCLING.
Reproduction Cost
Required Depreciation Reserve
Required Radiation
The area of radiator surface required based on the heat loss computation for the space to be heated.
Reservation Fee
A charge for a unit of capacity reserved on a pipeline for firm transportation of customer-owned gas pursuant to Part 284 of the Commission's regulations. Section 284.8(d) of the regulations states that the fee may not recover any variable costs or any fixed costs in excess of those costs that would be recovered by using the same ratemaking methodology used for determining the demand charge in the pipeline's sales rates. The pipeline's tariff must state the maximum reservation fee. Because the reservation fee may not include any variable costs, the fee may be discounted to zero.
Reserve for Deferred or Future Income Taxes
An account prescribed by some state utility commissions, the accounting profession, and the FERC to record the accumulated balances (net after write-off) of the provisions made in prior years for income taxes to be paid in subsequent years.
Reserve Life Index (RLI)
The ratio of a pipeline's system supply reserves to annual sales expected, stated in years. This ratio is often used to help determine a pipeline's rate of return.
Reserve Rates
Rates used internally by the company to adjust the rates billed and subject to refund to an estimate of the final or settled rate. Accounting principles require such a reserve.
Reserve Ratio
Reserves, Energy
Refers to the bank of natural resources, such as natural gas, natural gas liquids, petroleum, coal, lignite, energy available from water power, and solar and geothermal energy. Estimated Potential Natural Gas Resources. Refers to an estimate of the remaining natural gas in a specified area which are judged to be recoverable. Estimated Proved Natural Gas Reserves. An estimated quantity of natural gas which analysis of geologic and engineering data demonstrates with reasonable certainty to be recoverable in the future from known oil and gas reservoirs under anticipated economic and current operating conditions. Reservoirs that have demonstrated the ability to produce by either actual production or conclusive formation test are considered proved.
Reserves-to-Production (R/P) Ratio
A ratio of the size of a gas and/or oil field to the annual production capacity of that field which is used to estimate the productive life of the field.
That portion of a resource that has been actually discovered and that is presently technically and economically extractable. Also, a rock stratum that forms a trap for the accumulation of oil and gas. Also, a natural, subsurface container of fluids.
Reservoir Energy
The amount of energy available in a gas or oil reservoir for producing the gas or oil by natural flow.
Reservoir Pressure
The pressure existing at the level of the oil or gas productive formation in a well.
A solid, semisolid, or pseudosolid organic material, often of high molecular weight, which exhibits a tendency to flow when subjected to stress, usually has a softening or melting range, and usually fractures conchoidally.
Restructuring Proceedings
Negotiations wherein each interstate pipeline and its customers determine how they will conduct business pursuant to the provisions of Order 636.
Retirement Dispersion
The pattern of retirements taking place at various ages in relation to the average service life or, simply, the scattering of retirements about average life.
Retirement Frequency
Retirement Frequency Curve
A graphical presentation of the retirement dispersion.
Retirement Units
(Definition taken from the FERC Uniform System of Accounts, effective April 1, 1986.) "Retirement Units" means those items of plant which, when retired, with or without replacement, are accounted for by crediting the book cost thereof to the plant account in which included. ("Definitions" Item 32.) Each utility shall use list of retirement units as is in use by it at the effective date hereof or as may be prescribed by the Commission, with the option, however, of using smaller units, provided the utility's practice in this respect is consistent.
Cost of utility plant retired from service, whether or not it has been physically removed or replaced.
An investment made in an existing building or facility. May be equipment replacements, equipment add-ons, or shell and equipment improvements.
Generally, interest on debt and the profit the company is allowed over and above the recovery of its operating expenses, depreciation and taxes.
Return Air
Air returning to a heater or conditioner from the heated or conditioned space.
Return on Equity
The ratio of net income or earnings (after all expenses are deducted) to the book value of common and preferred stock plus retained earnings.
Revenue Requirement
The amount of revenues the utility needs to receive in order to cover operating expenses, pay debt service, and provide a fair return to common equity investors.
Reverse Circulation
Normal course of drilling fluid circulation is downward inside the drill pipe and upward in the well bore space surrounding the drill pipe. On special problems, this normal circulation is sometimes reversed and the fluid returns to the surface through the drill pipe after being pumped down in the annular space.
Reverse South Georgia Method
Works in the reverse of the SOUTH GEORGIA METHOD. The method was adopted shortly after the Tax Reform Act of 1987 was enacted. The Act reduced the statutory corporate income tax rate from 46% to 34%, which caused the balance in the Deferred Tax Account to be overstated. The "Reverse South Georgia Method" determines the amount of the overstatement and amortizes the excess as a reduction to the cost of service income tax allowance over the remaining book life of the pipeline. See SOUTH GEORGIA METHOD, NORMALIZATION, ACCOUNTING and PROVISIONS FOR DEFERRED INCOME TAXES.
Rig, Jackknife, or Folding Mast
The type mast that can be folded for moving, as contrasted with the standard derrick, which has to be completely dismantled and re-erected.
Rigging Up
Before the work of drilling can be started but after the derrick has been built, tools and machinery must be installed and a supply of fuel and water must be established. This operation, which in substance is that of getting the rig ready, is conveniently described by the drillers' term "rigging up".
A strip of land, the use of which is acquired for the construction and operation of a pipeline or some other facility; may be owned outright or an easement taken for a specific purpose.
Rigid PVC
Polyvinyl chloride or a polyvinyl chloride/acetate copolymer characterized by a relatively high degree of hardness; it may be formulated with or without a small percentage of plasticizer. Normally a straight piece of pipe, not readily flexible.
A very short length of pipe cut for testing purposes, such as for the ring-tensile test.
Ring-Tensile Test
Method of determining apparent tensile strength of plastic pipe by applying tensile forces in the hoop direction to a ring-specimen cut from pipe.
General term for vertical runs of gas piping.
Risk Premium
A method to determine the cost of common equity component of return using the bond yield plus a risk premium based on selected stock market yields to bond yields. Also called BOND YIELD RISK DIFFERENTIAL.
Long, heavy iron or concrete sleeves installed on a pipeline to prevent injury to pipe laid in a river bottom and to weight the pipe. Sometimes known as river weights or dogs.
Rock Pressure
A term used for the initial pressure of gas in a well.
Rolled-In Pricing
Current practice where rates reflect the accumulation or overall cost of all gas purchases. See INCREMENTAL PRICING.
Rolling Weighted Average Inventory Costing Methodo
A method of pricing gas inventory for PGA purposes in which storage injections are priced at the month's jurisdictional system cost of purchased gas and storage withdrawals are priced by dividing the total purchase cost of the gas in storage by the quantity of gas in storage.
The rapid release of vapor when stratified layers of LNG suddenly mix.
Room Heater
Rotary Bit
The cutting tool attached to the lower end of the drill pipe of a rotary drilling rig. The bit does the actual drilling of the hole through the formation.
Rotary Drilling
A method for drilling wells using a cutting bit attached to a revolving drill pipe.
A driller's helper and general all-around worker on a drilling rig.
Round Trip
The removal of drilling bit and drill pipe from a well and replacing them as required to change the bit or test the table.
A laborer who assists the foreman in the general work about producing oil wells and around the property of the oil company. The roustabout is a semi-skilled laborer in that he requires considerable training to fit him for his work.
The amount paid to the owner of mineral-rights as payment for minerals removed. In gas and oil operations, the royalty is usually based on a percentage of the total gas or oil production.
An assembly of more than one piece of pipe; a portion of a fitting having its end in line or nearly so, as distinct from the branch or side opening, as of a tee.
A failure in the pipeline for various reasons where a complete loss to atmosphere of the gas or other media is sustained.


Removal CostsThe costs of disposing of plant, whether by demolishing, dismantling, abandoning, sale, or other. Removal costs increase the amount to be recovered as depreciation expense.


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