Petrochemical Abbreviation(ranjit Kumar-sk E&c)

PETROCHEMICAL ABBREVIATION

ABSOLUTE PRESSURE Pressure measured with respect to zero pressure, as distinct from pressure measured with respect to some standard pressure such as atmospheric pressure. Thus, 2 Bar gauge (i.e. atmospheric) is equivalent to 3 Bar absolute. (Atmospheric pressure being 1 bar absolute). ABSOLUTE TEMPERATURE A temperature at which zero is a condition absolutely free of heat and equivalent to -459oF or –273oC. To convert temperature on Fahrenheit or centigrade scales to degrees absolute, add 459 or 273 respectively.

ACCELERATOR 1. A substance that hastens a reaction, usually by acting as a catalyst, as in the vulcanization of rubber. 2. Any of several automobile attachments for increasing the speed at will, especially a foot-operated throttle. ACCUMULATOR A vessel for the temporary storage of a gas or liquid; usually used for collecting sufficient material for a continuous charge to some refining process. ACETYLENE C2H2 A highly unsaturated hydrocarbon gas usually made by the action of water on calcium carbide and by pyrolysis of natural gas. It is largely used in industry for cutting and welding metals. Several important intermediates have been synthesised from acetylene but a cheaper route via ethylene has now been developed for many of them.

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ACID A member of an important and fundamental category of chemical substances characterised by having an available reactive hydrogen and requiring an alkali to neutralise them. Acid solutions usually have a sour, biting and tart taste, like vinegar. ADDITIVE A substance added to a product in order to improve its properties. ADIP TREATING A process for removal of hydrogen sulphide from hydrocarbon gases and LPG by a specific regenerable solvent. Carbon dioxide and, to a certain extent, carbonyl sulphide can be removed at the same time. The solvent employed is an aqueous DIPA solution. ADSORPTION PROCESS A fractionation process based on the fact that certain highly porous materials preferentially adsorb certain types of molecules on their surface, e.g. PSA units. AEROMETER An instrument for ascertaining the weight or density of air or other gases. AGGREGATE As applied to non-bituminous materials, the inert material, such as sand, gravel, or broken stone, with which cementing material is mixed to form a mortar or concrete. AIR-BLOWN ASPHALT Asphalt produced by blowing air through residual oils or similar mineral oil products at moderately elevated temperatures. AIR HEAT EXCHANGER A heat exchanger in which air is used as the cooling medium. 2. Created by Ranjit Kumar

AIR SWEETENING In this process sour gasoline fractions are sweetened by dissolving air in the hydrocarbon phase followed by contacting with a strong NaOH aqueous solution. The reaction products formed are disulphides which dissolve in the sweetened gasoline and water remaining in the aqueous phase. ALCOHOLS A class of organic compounds containing oxygen (as a hydroxyl), of which ethyl alcohol (the alcohol of potable spirits and wines) is the best known. They can react with acids to form esters. They are largely used as solvents. ALIPHATIC HYDROCARBONS Hydrocarbons in which the carbon atoms are arranged in open chains, which may be branched. The term includes paraffins and olefins and provides a distinction from aromatics and naphthenes which have at least some of their carbon atoms arranged in closed rings. ALKALI In chemistry, any substance having marked basic properties. In its restricted and common sense, the term is applied only to hydroxides of ammonium, lithium, potassium, and sodium. They are soluble in water, they have the power of neutralising acids and forming salts with them and of turning red litmus blue. In a more general sense, the term is also applied to the hydroxides of the socalled alkaline earth metals - barium, calcium, and strontium. ALKALI TEST A test to determine the presence or absence of free alkali in finished oils after chemical purification. ALKALINE Having the properties of an alkali; opposite to acidic. ALKALINITY The amount of free alkali in any substance. 3. Created by Ranjit Kumar

ALKYLATION A reaction in which a straight-chain or branched-chain hydrocarbons group, which is called an alkyl group or radical, is united with either an aromatic molecule or a branched-chain hydrocarbon. Used for detergent or petroleum manufacture. Usually catalysed by Hydrofluoric or Sulphuric acid. ALLOY A substance composed of two or more metals, or of a metal and a nonmetal, intimately united, usually by being fused together and dissolved in each other when molten. AMERICAN PETROLEUM INSTITUTE An association incorporated in the United States, having as its object the study of the arts and sciences connected with the petroleum industry in all its branches and the fostering of foreign and domestic trade in American petroleum products. AMERICAN SOCIETY FOR TESTING MATERIALS An association incorporated in the United States for promoting knowledge of the properties of engineering materials and for standardising specifications and methods of testing. AMINE Hydrocarbon with attached Ammonia group having absorbent properties, making it useful in treatment processes (ADIP, SULFINOL). AMMONIA NH3 Ammonia is manufactured by the direct combination of hydrogen and nitrogen under pressure over a catalyst. Anhydrous ammonia is mainly used for the manufacture of nitrogenous fertilisers, but is used at NZRC for pH control in various processes. A colourless, gaseous compound, NH3 is of extremely pungent smell and taste and is very soluble in water. ANAEROBIC Existing in an oxygen free condition. 4. Created by Ranjit Kumar

ANHYDROUS Free of water. ANILINE POINT The minimum temperature for complete miscibility of equal volumes of the chemical aniline and a petroleum product. In conjunction with API gravity the aniline point may be used to calculate the net heat of combustion of aviation fuels or the diesel index of diesel fuels. The lower temperature at which an oil product is completely miscible with aniline in a 1:1 volumetric ratio. ANNEALING Heating and slowly cooling to increase the ductility or remove internal stresses, as of metal or glass. ANTIFOAM AGENT An additive used for controlling foam. Antifoam agents are used in some lubricating oils. At NZRC, used as additives in ADIP, Sulphinol and BDU Units. ANTI-KNOCK An adjective signifying resistance to detonation (pinking) in spark-ignited internal combustion engines. Anti-knock value is measured in terms of octane number of gasoline engines and of cetane number for diesel fuels. ANTI-KNOCK AGENT A chemical compound such as tetramethyl-lead which, when added in small amounts to the fuel charge of an internal-combustion engine, tends to lessen knocking. ANTI-STATIC ADDITIVE An additive for reducing static properties, notably in Kerosene. API GRAVITY 5. Created by Ranjit Kumar

In the USA an arbitrary scale known as the API degree is used for reporting the gravity of a petroleum product. The degree API is related to the specific gravity scale (15°C/15°C) by the formula: 141.5 Degree API = Sp. Gr. 15°C/15°C - 131.5

AROMATICS A group of hydrocarbons characterised by their having at least one ring structure of six carbon atoms, each of the latter having one valency outside the ring. If these valencies are occupied by hydrogen atoms, hydrocarbon radicals, or inorganic groups one speaks of condensed aromatics. These hydrocarbons are called aromatics because many of their derivatives have an aromatic odour. They are of relatively high specific gravity and possess good solvent properties. Certain aromatics have valuable anti-knock characteristics. Typical aromatics are: benzene, toluene, xylene, phenol (all mono-aromatics) and naphthalene (a di-aromatic). Aromatics can cause smoke and freeze point problems in Kerosene. ASH The solid residue left when combustible material is thoroughly burned. ASH CONTENT The percent by weight of residue left after combustion of a sample of a fuel oil or other petroleum oil. ASPHALT This term may have several meanings: 1. It refers to a mixture of bitumen and mineral aggregate, as prepared for the construction of roads or for other purposes. 2. In the United States it refers to the product which is known as bitumen elsewhere. Black to dark-brown solid or semisolid cementitious material which gradually liquefies when heated and 6. Created by Ranjit Kumar

in which the predominating constituents are bitumens. These occur in the solid or semisolid form in nature: are obtainable by refining petroleum; or are combinations with one another or with petroleum or derivatives thereof. 3. At NZRC - very heavy fuel oil produced as bottom product from BDU (short residue with DAO removed). ASPHALTENES Polyaromatic constituents of asphaltic bitumen characterised by being insoluble in aromatic-free low-boiling petroleum spirit, but soluble in carbon disulphide. ASPHALTIC BASE CRUDE OILS Crude oils which contain little or no paraffin wax but usually contain asphaltic matter. Now often referred to as naphthene base crude oils. ASPHALTIC BITUMEN The full name for bitumen adopted by the Permanent International Association of Road Congresses. ASPIRATOR An apparatus which serves to create a partial vacuum through pumping a jet of water, steam, or some other fluid or gas past an orifice opening out of the chamber in which the vacuum is to be produced. ASSOCIATED NATURAL GAS Natural gas associated with oil accumulations by being dissolved in the oil under the reservoir temperatures and pressures (solution gas) and often also be forming a gas cap of free gas above the oil (gas cap gas). ASTM DISTILLATION Any distillation made in accordance with an ASTM distillation procedure; and, especially, a distillation test made on such products as gasoline and kerosene to determine the initial and final boiling points and the boiling range. 7. Created by Ranjit Kumar

ASTM MELTING POINT The temperature at which wax first shows a minimum rate of temperature change, also known as the English melting point. ATMOSPHERIC PRESSURE 1. The pressure of air. 2. More specifically, the pressure of the air at sea level. 3. As a standard, the pressure at which the mercury barometer stands at 760mm, or 30in. (equivalent to approx. 14.7 psi). ATOM The smallest complete particle of an element which can be obtained, yet retain all physical and chemical properties of the element. According to present theory, the atom consists of a nucleus of neutrons and positively charged protons, surrounded by negatively charged particles called electrons. AUTO IGNITION POINT The temperature at which the vapour given off by a sample will ignite in air without any ignition source. AVERAGE BOILING POINT Unless otherwise indicated, the sum of the ASTM distillation temperatures in steps of 10°C from the 10-percent point to the 90-percent point, inclusive, divided by 9. Sometimes half the initial and half the maximum distillation temperatures are also added, and the sum then divided by 10. AVIATION GASOLINE Any of the special grades of gasoline suitable for use in certain aeroplane engines. Not made by NZRC. AVTUR Kerosene type aviation turbine fuel, (Jet A1).

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B BACK PRESSURE 1. The pressure on the outlet or downstream side of a flowing system. 2. In an engine, the pressure which acts adversely against the piston, causing loss of power. BAFFLE A partial restriction, generally a plate, located so as to change direction, guide the flow, or promote mixing within the equipment in which it is installed. BALANCED DRAUGHT A method of furnace air control using both forced and induced draught fans. BAROMETRIC CONDENSER A device for condensing steam by direct contact with water. It produces a partial vacuum in refinery equipment such as a vacuum distillation unit. BAROMETRIC LEG Water filled tube for sealing vacuum systems. (See also Liquid Seal). BARREL A standard measure of crude oil quantities; equivalent to 35 imperial gallons, 42 US gallons or 159 litres. BASIC SEDIMENT AND WATER The heavy material which collects in the bottom of storage tanks, usually composed of oil, water, and foreign matter. Also called bottoms, bottom settlings, etc. It is measured in all incoming feedstocks. BATCH 9. Created by Ranjit Kumar

Any quantity of material handled or considered as a unit in processing. BATCH PROCESS Any process in which a quantity of material is handled or considered as a unit. Such processes involve intermittent, as contrasted to continuous operation. BATTERY A series of individual items of refinery equipment operated as a unit. BATTERY LIMITS A term used when a unit or a battery is to be built in a refinery by an outside contractor or construction company. It specifies the area within which the contractor shall supply all services, and defines the limits beyond which this shall be done by the refinery. Also defines plant interface limits. BEARING A support for holding a shaft in its correct position. Examples: journal bearings to confine radial motion, thrust bearings to control axial movement, and "rolling element" bearings which are used in both services. BENZENE C6H6 The parent compound of the aromatic hydrocarbon series. It is used in the manufacture of a large number of chemicals including phenol, styrene, detergent alkylate and insecticides and is a major component of platformate. BIOCHEMICAL OXYGEN DEMAND (BOD) Important water test that shows the amount of bio-degradable matter in the water. Amount of oxygen required by aerobic organisms for breakdown of organic matter in water over a 5 day period. BIODEGRADATION 10. Created by Ranjit Kumar

Degradation of solid materials by bacterial consumption. BIOTREATER Process for biological degradation of effluent water. BITUMEN A non-crystalline solid or semi-solid cementitious material derived from petroleum, consisting essential of compounds composed predominantly of hydrogen and carbon with some oxygen and sulphur, it gradually softens when heated. Bitumen’s are black or brown in colour. They may occur naturally or may be made as end products from the distillation of, or as extracts from, selected petroleum oils. BLACK PRODUCTS Fuel oils, bitumen’s and residues. BLEEDING Divert or release a small portion of the material contained in a line or vessel, usually by opening a valve slightly. BLEND Any mixture prepared for a special purpose, e.g. the products of a refinery are blended to suit market requirements. BLENDED FUEL OIL A mixture of residual and distillate fuel oils. BLENDING Mixing of the various components in the preparation of a product of required properties. BLENDING STOCK Any of the stocks used to make commercial gasoline. These include: straight-run gasoline, cracked gasoline, and synfuel among others. 11. Created by Ranjit Kumar

BLENDING VALUE (ANTI-KNOCK) Some anti-knock blending agents possess the property of apparently increasing the rated octane number of certain gasoline base stocks to a higher octane number than their own value in terms of octane numbers. This property is known as the blending value. BLOCKED OPERATION The use of a single process unit alternately in more than one operation. BLOWBACK A system in which a liquid or a gas is continuously bled through the lead lines of an instrument meter into the main line. This prevents the main line fluid from coming in contact with the meter body, thus eliminating vaporisation, corrosion or plugging. BLOWDOWN The act of flushing or clearing a piece of pressurised equipment by blowing to a drain (or similar). Term is often used by Boilermen, continuos blowdown indicating blowdown from the Steam Drum or Scum level, and Intermittent Blowdown from the bottom header of a boiler. BLOWER Usually an enclosed fan used in a forced/induced/balanced draught furnace to provide the combustion air. BLUE SMOKE A blue exhaust smoke from a diesel engine, indicating that only a part of the fuel is being burned; also called cold smoke. BOILING POINT (AT A GIVEN PRESSURE) The temperature at which a liquid, contained in a closed vessel under a given pressure, will form a first bubble of vapour on the addition of heat. Further heating of the liquid at its boiling point results in evaporation of part or all of the liquid. 12. Created by Ranjit Kumar

BOILING RANGE Petroleum products (which are mixtures of many compounds, each having a different boiling point) do not have a simple boiling point but have a boiling range instead, i.e. the temperature range from boiling point to dew point. BOMB A small pressure vessel, such as used for taking samples of HP gases and LPG. BOND 1. Chemically, a unit link between atoms. In graphic chemical formulas, it is often represented by a short line or dash. 2. Electrically, a common grounding system e.g. Bonding wires used between fuel tanker and petrol station ground tanks or airport delivery systems and aircraft. BOOSTER STATION An auxiliary station consisting of suitable storage tanks, motive power and pumps for pumping oil through pipelines. BOTTLED GAS Ordinarily, butane or propane, or butane-propane mixtures, liquefied and bottled under pressure for domestic use. BOTTOMS The bottom product from a distillation of petroleum; also the liquid layer left in a tank or similar container after draining to the level of the pump suction. BOX-IN To isolate a piece of equipment, usually by block valves. BOX-UP The act of closing up a piece of refinery equipment following construction, maintenance, inspection etc. 13. Created by Ranjit Kumar

BRAKE HORSEPOWER That horsepower delivered by an engine to a brake or dynamometer. It is less than the indicated horsepower by the amount lost in transmission bearings, gear teeth, belts, etc. BREAKER POINT The point of contact actuated by a cam to break the primary circuit in the ignition system and thereby cause a current surge in the secondary circuit which produces the spark. BREATHING When a storage tank containing volatile products is heated by solar radiation, some of the liquid contents evaporate. The excess vapour thus formed is blown out to the atmosphere. On cooling, the less volatile components of the vapour contents condense and a slight vacuum is created, causing air from outside to be sucked into the tank. This double action is referred to as "breathing" of the tank. The movement of gas (oil vapours or air) in and out of the vent lines of storage tanks as a result of alternate heating and cooling. BRITISH THERMAL UNIT (BTU) The quantity of heat required to raise the temperature of 1lb of water through 1°F. 1.000 Btu = 252 kcal. BUFFER 1. A vessel for temporary storage of liquid (buffer drum). 2. A chemical used to maintain another within set limits of (e.g.) pH. A device to polish the floor. An old Navel name for a person in-charge of the deck of a Ship. BUNKER FUEL Any fuel oil or diesel fuel taken into the bunkers of ships. BURNING OIL 14. Created by Ranjit Kumar

An illuminating oil, such as kerosene, mineral seal oil, etc. suitable for burning in a wick lamp. BUTANE C4H10 Commercial butane is a mixture of two gaseous paraffins, normal butane and isobutane. When blended into gasoline in small quantities it improves volatility and octane number. Butane can be stored under pressure as a liquid at atmospheric temperatures ("bottled gas") and it is widely used for cooking and domestic heating. Used at NZRC in the reformer and BDU. BUTANE DE-ASPHALTING A solvent extraction process whereby a short residue is split into components having low (D.A.O.) and high (Asphalt) asphaltic content by contact with liquid butane. BYPRODUCT A secondary or additional product not of primary importance. (e.g. Sulphur).

C C1,C2,C3,C4,C5 A common way of representing fractions containing a preponderance of hydrocarbons of 1, 2, 3, 4 or 5 carbon atoms, respectively, without reference to hydrocarbon type. CALIBRATION The determination of fixed reference points on the scale of any instrument by comparison with a known standard and the subsequent subdivision or graduation of the scale to enable measurements in definite units to be made with it. Also the process of measuring or calculating the volumetric contents or capacity of a receptable. CALORIE

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The amount of heat required to raise the temperature of 1 gram C). In calculations the k calorie,° to 15.5°C (from 14.5°of water through 1 equal to 1,000 calories is often used. 1,000 kilocalories = 3,968 Btu. CALORIFIC VALUE The calorific value of a combustible material is the quantity of heat produced by complete combustion of unit weight of the material. The units in which the calorific value is usually given are (a) calories per gram and (b) British Thermal Units per pound. The systems may be converted by the relationship: 1 calorie per gram = 1.8 Btu per lb. CANDLEPOWER The illuminating power of a standard candle employed as a unit for determining the illuminating quality of kerosene and other illuminants. One international candle or one American candle equals 1.11 Hefner candles. CAPILLARITY That physical action by which the surface of a liquid, where it is in contact with a nonhorizontal solid surface (as in vertical capillary tube), is elevated above or depressed below the level of the liquid. Its magnitude is determined by the interfacial tensions involved. CARBON A nonmetallic element existing in diamonds, graphite, and numerous amorphous forms; combined as carbon dioxide, carbonates, and in all living things. Carbon is unique in forming an almost infinite number of compounds (it is present in all organic compounds). CARBON (FIXED CARBON) In the case of coal, coke, and bituminous materials, the solid residue other than ash contained by destructive distillation. CARBON DEPOSIT

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Engine deposits containing soot from over-rich fuel mixtures and the carbon residue and tars from decomposed lubricating oil. Road dust, metal particles, gum and tarry substances also form a part of such deposits. CARBON DIOXIDE A heavy, colourless gas, CO2, which will not support combustion. Dissolved in water, it forms carbonic acid. It is exhaled by lung-possessing animals as a waste gas, but is inhaled by certain plants which absorb its carbon and release its oxygen as a waste gas. CARBON MONOXIDE A colourless, odourless gas, CO; a product resulting from the incomplete combustion of carbon. It is very poisonous. CARBURETTOR A device for metering the correct mixture of air and gasoline to an internal-combustion engine. CARRYOVER Relatively nonvolatile contaminating material which is carried over by the overhead effluent from a fractionating column, absorber, or reaction vessel. It may be carried as liquid droplets or finely divided solids suspended in a gas, a vapour, or a discrete liquid. CASCADE TRAY A fractionating device consisting of a series of parallel troughs arranged in stair-step fashion. Liquid from the tray above enters the uppermost trough. Liquid thrown from this trough by vapour rising from the tray below impinges against a plate and a perforated baffle. Liquid passing through the baffle enters the next lower of the troughs. CATALYSIS The alteration of the rate of a chemical reaction by the presence of a "foreign" substance (catalyst) that remains unchanged at the end of the reaction. 17. Created by Ranjit Kumar

CATALYST In technology this word means a substance added to a system of reactants which will accelerate the desired reactions, while emerging virtually unaltered from the process. The catalyst allows the reaction to take place at a temperature at which the uncatalyzed reaction would proceed too slowly for practical purposes. Used extensively in secondary processes. CATALYST POISON Generally, coverage of the catalyst surface with nonreactants. If a large fraction of the catalyst surface is covered selectively by any one strongly adsorbed chemical, the catalytic reaction will be drastically reduced in rate. This circumstance is called poisoning, and self-poisoning can result when one reactant or product is much more strongly adsorbed than another reactant. May be reversible, but can destroy entire catalyst inventory. CATALYTIC PROCESS Any process which employs catalysis. Examples : Hydrocracking, Platforming and hydrotreating. CATALYTIC REFORMING Process of changing the molecular structure of the components of straight-run gasoline or of a gasoline fraction by subjecting the gasoline to thermal treatment in the presence of a catalyst (for example platinum). By this process the anti-knock performance of the gasoline is improved. CATHODIC PROTECTION Method of protecting tanks, ships, pipelines and jetties against corrosion. By reversing the electric current which flows away from a corroding metal, a corrosion process can be arrested. CAUSTIC SODA The name used in industry for sodium hydroxide (NaOH) on account of its property of corroding the skin. It is strongly alkaline. Used extensively in water treatment or pH control in process units. 18. Created by Ranjit Kumar

CENTRIGRADE (CELSIUS) SCALE A thermometer scale on which the interval between the freezing point and boiling point of water is divided into 100 parts or degrees F. Also called°C to 212°F and 100°C corresponds to 32° centigrade, so that 0 Celsius after Anders Celsius who first described it. CENTIPOISE, CENTISTOKES A Centipoise (cP) is 1/100th of a poise (P) which is the fundamental unit of dynamic viscosity in the centimetre-gram-second system of C is approximately 1 cP. The centistokes°units. The viscosity of water at 20 (cS) is 1/100th of a stoke (S) which is the fundamental unit of Kinematic viscosity in that system. The two c viscosity’s are related by the density, i.e. number of centistokes = number of Centipoise divided by liquid density (in g/cm3). CENTRIFUGAL COMPRESSOR A machine in which pressure is built up by means of rotating fans or blades. CENTRIFUGAL PUMP A pump that derives its pressure increase from the centrifugal force generated when the impeller throws the liquid outwards at high speed. CENTRIFUGE A whirling instrument for separating liquids and solids or liquids of different specific gravity by use of centrifugal force. CERAMIC BALLS Balls of chemically inert ceramic, used as filler and support in reactors etc. CETANE NUMBER The cetane number of a diesel fuel is a number equal to the percentage by volume of cetane in a mixture with 19. Created by Ranjit Kumar

alph-methyl-naphthalene having the same ignition quality as the fuel under test. CFR ENGINE A standard single-cylinder variable compression engine developed by the Co-operative Fuel Research Council, to determine the anti-knock value of motor gasoline’s or the ignition quality of diesel fuels. CHANNELING Non uniform flow of process fluid through (e.g.) a reactor bed. CHARACTERISATION Identifying a feed or product by its properties e.g. distillation, carbon: hydrogen ration, density etc. CHAR VALUE In the 24 hours kerosene burning test the amount of char formed on the wick under prescribed conditions is measured and reported as mg/kg. CHECK VALVE (NON RETURN VALVE) An automatic valve which permits fluids to pass in one direction but closes when the fluids attempt to pass in the opposite direction. CHEMICAL OXYGEN DEMAND (COD) Total amount of oxygen needed for oxidation of all organic matter in water to CO2 and H2O. CHLORINATION A chemical reaction in which chlorine reacts with hydrocarbon and one or more of the hydrogen atoms are replaced by atoms of chlorine, or chlorine reacts with an unsaturated hydrocarbon and two chlorine atoms (one molecule) are added to the double bond. CHROMOMETER - See Colorimeter 20. Created by Ranjit Kumar

CLADDING A homogeneous bonded or resistance-welded metallic liner applied to a base metal such as carbon steel. Used in lines, vessels, and heat exchanger equipment to reduce corrosion and increase service life. Also called clad lining. CLAUS PROCESS Process for the manufacture of sulphur from H2S, comprising oxidation of part of the H2S to SO2 in a thermal reaction stage, followed by catalytic reaction of the remaining H2S with the SO2 formed to give sulphur. CLEAR GASOLINE A gasoline which is free from anti-knock additives such as tetraethyl-lead. In making comparative engine tests between leaded and unleaded fuels, the clear, unleaded gasoline is sometimes referred to as straight gasoline base, base fuel, or as gasoline "neat". CLOUD POINT The temperature at which a fuel, when cooled, begins to congeal and present a cloudy appearance owing to the formation of minute crystals of wax. COALESCER A vessel packed with steel wool, glass wool, polypropylene wool or felt used to remove fine droplets of treating liquids or water from a petroleum product. COASTAL TANKER Ltd- (CTL) A Company responsible for coastal tanker movements in NZ COEFFICIENT OF EXPANSION The ratio of the increase of length, area, or volume of a body F) to the original length, area, or°for a given rise in temperature (usually 1 volume of the body. COKE 21. Created by Ranjit Kumar

Hard carbon deposit, usually formed by the unintentional thermal cracking of heavy residues. COKE DRUM A vessel in which coke is formed or collected and which can be cut off from the process for cleaning. COLD FILTER PLUGGING POINT The highest temperature at which a fuel ceases to flow through a test filter. COLORIMETER An instrument for determining the colour of oil product by measuring the percentage transmission of monochromatic light through the liquid. COMBINED FEED RATIO (CFR) The ratio of the 2nd to 1st stage feed on the Hydrocracker. COMBUSTION The process of burning; rapid oxidation caused by the union of the oxygen of the air with a material. COMBUSTION CHAMBER The space in which the process of burning takes place e.g. in a jet engine. COMPATABILITY Ability of additives or products to mix together without separation or reaction. COMPOUND A substance formed by the combination of two or more ingredients in definite proportions by weight, and possessing physical and chemical properties entirely different from those of the ingredients. e.g. table salt, paint. 22. Created by Ranjit Kumar

COMPRESSION In general, the act of increasing the pressure on gas or vapour. It is usually attended by a reduction in volume. COMPRESSION IGNITION The combustion which takes place when fuels are injected in a C) in the cylinder of a diesel°fine spray into the hot compressed air (500 (compression ignition) engine. The heating of the air is due to its rapid compression by the piston. COMPRESSION RATIO The ratio of the cylinder volume when the piston of an engine is at the crank end of the cylinder, to the volume when the piston is at the head end. COMPRESSOR A device which draws in air or other gases, compresses it and discharges it at a high pressure. CONDENSATE Liquid hydrocarbons which are sometimes produced together with natural gas. In general: the liquid that is formed when a vapour cools. CONDENSATION (PHYSICAL) The transfer of a material from the vapour phase into the liquid phase, for example by the withdrawal of heat. CONDENSER A special type of heat exchanger for the removal of heat from e.g. the top of a fractionating column. CONDENSER BOX A large box-shaped structure in which the condenser, which may consist of coils or tubes, is submerged in a heat-absorbing medium, usually water. 23. Created by Ranjit Kumar

CONDUCTIVITY A materials ability to conduct an electrical charge. Important in water treatment (as an indication of impurities) and some hydrocarbons (static risk). CONTINUOUS CATALYST REGENERATOR see Fluid bed operation. CONTINUOUS DISTILLATION An operation in which the steps of charging, heating, vapourisation, fractionation, and collection of products are performed continuously rather than in a batchwise manner. The unit employed is known as a continuous still. CONTROL LOOP Combination of control signal, feedback signal and instrumental response that characterises an automatic control system. CONTROLLER The actual control instrument is the controller. However, the word is often used in reference to the control valve that acts on the process. CONVECTION The flow of heat through liquid or gas by actual mixing of the fluids (physical turbulence). CONVECTION SECTION That portion of the furnace in which tubes receive heat by convection from the flue gases (contrast with radiant section). CONVENTIONAL PRODUCTS Petroleum products which are manufactured from crude oil by physical separation processes. (See primary processes). CONVERSION PROCESSES 24. Created by Ranjit Kumar

Manufacturing processes which involve a change in the structure of the hydrocarbons (See secondary processes). COOLER A heat exchanger whose primary purpose is to reduce the temperature of one of the passing fluids. COOLING TOWER A unit or structure, for the purpose of cooling by evaporation. COPPER STRIP CORROSION A qualitative method of determining the corrosivity of a product by its effect on a small strip of polished copper suspended or placed in the product. One of the kerosene quality tests. CORRECTED ENERGY & LOSS (CEL) Yardstick used for monitoring refinery efficiencies. CORROSION The gradual eating away of metallic surfaces as the result of chemical action such as oxidation. It is caused by corrosive agents such as acids. COUNTERCURRENT FLOW A system in which one fluid flows in one direction and another fluid flows in the opposite direction e.g. in a heat exchanger, in which the direction of flow of the cold oil is opposite to that of the hot oil. CRACKING Process whereby the large molecules of the heavier oils are converted into smaller molecules of the gasoline type. When this is brought about by heat alone, the process is known as thermal cracking. If a catalyst is also used the process is referred to as catalytic cracking (in speech generally abbreviated to cat. cracking) or Hydrocracking if the process is conducted over special catalysts in a hydrogen atmosphere - other processes include visbreaking and hycon. 25. Created by Ranjit Kumar

CREEP Change in the micro structure of a metal. The continuous stretching which occurs when metal is under stress or pressure, especially apparent when at high temperatures. CRITERIA REFERENCED INSTRUCTION Method of instruction based on meeting specific criteria. CRITICAL PRESSURE The pressure necessary to condense a gas at the critical temperature. CRITICAL TEMPERATURE The maximum temperature at which a gas can be liquefied by pressure (critical pressure); above this temperature the gas cannot be liquefied, no matter what pressure is applied. CRITICAL VELOCITY The rate of flow in a pipe at which streamline flow changes into turbulent flow. CRUDE NAPHTHA Light distillate made in the fractionation of crude oil. CRUDE OIL TYPES See appropriate sub-heading for description. - Paraffin-base crude oils - Asphaltic-base crude oils - Mixed-base crude oils CRUDE WAX Crude wax, also called petroleum wax or slack wax, is an unrefined mixture of high-melting hydrocarbons, mainly of the normal straight-chain type, still containing a fairly high percentage 26. Created by Ranjit Kumar

of oil. It is obtained by filtration (as such, or after addition of a solvent) from high boiling distillates or residual oils. Slack wax is primarily obtained as by-product in the manufacture of lubricating oils. The crude wax made from distillate oils is refined to make a range of microcrystalline waxes. CRYSTALISATION A fractionation process based on the difference in freezing point of the various constituents of the mixture to be fractionated. The process is, for example, used in the separation of paraffins from lube oil (de-waxing). CUSTODY TRANSFER TANKS Tanks which receive products from external sources or deliver products to external sources CURRENT RATE Current Assets Current Liabilities CUT Refinery term for a fraction obtained direct from a fractionation unit. Several cuts can be blended for the manufacture of a certain product. CUT POINT (Between two process streams). The boiling point at atmospheric pressure of the component distributed in equal percentage in both process streams. CYCLISATION A reaction, for example, platinum-catalysed, by which a straight-chain paraffin hydrocarbon is converted into a naphthene and then into an aromatic: i.e. The process of changing an open-chain hydrocarbon structure to a closed ring, e.g. hexane to benzene. Accompanied by production of Hydrogen. CYCLONE SEPARATOR 27. Created by Ranjit Kumar

A conical vessel provided with a tangential inlet for a gas stream containing finely divided solids or liquid droplets, normally designed with a centrally located overhead gas withdrawal line. Powdered solids or coagulated liquids are separated by centrifugal force and pass downward along the incline (conical) to a centrally located outlet. In catalytic cracking, a pipe, known as a dip leg, is connected to this bottom outlet and serves to convey the solids back to the catalyst bed.

D DAMPER Usually a flap or shutter to control air flow in a furnace (may be in the supply and/or the flue ducting). DEACTIVATION Reduction in catalyst activity by poisoning or coating of catalyst particles by contaminants, or by a change in the physical structure of the catalyst particles. DEADWEIGHT The amount of cargo, stores and fuel which a vessel carries when loaded to the appropriate draught allowed by law. The difference between deadweight and displacement is the actual weight of the vessel. DEARATOR Device for the steam stripping of 02 and other gases from boiler feed water. DECOMPOSITION The breaking up of compounds into smaller chemical forms through the application of heat, change in other physical conditions, or introduction of other chemical bodies. DEFERRED TAXATION

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Provision for tax payable in the future, but deferred in the current year because of timing differences between the Company's accounts and the accounts required by the Inland Revenue Department. DEHYDRATION The removal of water from crude oil, from gas produced in association with oil, or from gas from gas-condensate wells. DEHYDROCYCLISATION Any process involving both dehydrogenation and cyclisation reactions. DEHYDROGENATION A reaction process in which hydrogen atoms are eliminated from a molecule. DEIONIZED WATER Water that has had all the free ions removed by ion-exchange, also called demineralised water. DEISOLATION The opposite of isolation i.e. To energise a piece of equipment. DEMISTER Any device used to stop passage of liquid droplets e.g. a demister section in a vacuum column is to stop the asphaltenes from the residue getting into the waxy distillate. DEMULSIFIER An additive used to prevent the formation of an emulsion applicable in crude/water emulsions in desalter. DEMURRAGE Amount payable to ship owner for failure to load or discharge ship within time allowed. 29. Created by Ranjit Kumar

DENITRIFICATION Removal of nitrogen compounds on feedstock by hydrogenation. N2 + 3H2 = 2NH3. DENSE BED LOADING Catalyst loading system of "raining" the catalyst onto the bed which achieves a higher loaded density than "sock" loading. DEOXYGENATION Removal of oxygen on feedstock by hydrogenation. 02 + 2H2 = 2H20. DESALTING A process to remove inorganic salts and other impurities from crude oil by mixing with water followed by settling in an electrostatic field. DESULPHURISATION - See Hydrodesulphurisation The removal of sulphur or sulphur compounds from a charge stock. DESUPERHEATER Equipment used to reduce the temperature of superheated steam. DETERGENCY The ability of a substance to clean and to wash away undesirable substance. Detergents may be either oil-soluble or water-soluble. Soap and synthetic detergents help to wet, disperse, and deflocculate solid particles. Oil-soluble detergents are used in motor oils to disperse, loosen, and remove carbon, dirt, etc. from interior surfaces of internal-combustion engines. DETERGENT OIL A lubricating oil possessing special sludge-dispersing properties for use in internal-combustion engines. These properties are usually conferred on the oil by the incorporation of special additives. Detergent oils hold sludge particles in suspension and thus promote engine cleanliness. 30. Created by Ranjit Kumar

DETONATION Detonation or knocking is the sharp metallic sound emitting from the cylinders of spark-ignition engines under certain conditions. It occurs when conditions in a cylinder are such that self-ignition of an unburnt mixture of fuel and air takes place. It reduces power output. DEW POINT (at a given pressure) The temperature at which a vapour, contained in a closed vessel under the given pressure, will form a first drop of liquid on the subtraction of heat. Further cooling of the vapour at its dew point results in condensation of part or all of the vapour as liquid. The dew point of a normal gasoline is approximately the same as the temperature at which 70% by volume distils over in the ASTM-distillation test. The dew point of a pure compound is the same as its boiling point. DEWAXING The process of removing paraffin wax from lubricating oils. DIESEL ENGINE As internal-combustion engine in which air drawn in by the suction stroke is so highly compressed that the heat generated ignites the fuel, which is automatically sprayed into the cylinder under high pressure. DIESEL FUEL A general term covering oils used as fuel in diesel and other compression ignition engines. DIESEL INDEX A measure of the ignition quality of a diesel fuel; the index is calculated from a formula involving the gravity of the fuel and its aniline point (API gravity times the aniline point (determining by ASTM D611-47T) divided by 100). DIFLUOROETHANE A catalyst promoter used on the Hydrocracker. 31. Created by Ranjit Kumar

DILUENT A liquid used to dilute or thin out another liquid. DIPPING A process for measuring the height of a liquid in a storage tank. This is usually done by lowering a weighted graduated steel tape through the tank roof and noting the level at which the oil surface cuts the tape when the weight gently touches the tank bottom (see Ullage). DISTILLATE The liquid obtained by condensing the vapour given off by a boiling liquid. Also the top product taken off a fractionating column; and in its broadest sense: any fraction other than the bottom product of the fractionator. DISTILLATION (fractional) A fractionation process based on the difference in boiling point of the various constituents of the mixture to be fractionated. It is carried out by evaporation and condensation in contact with reflux. When applied to the separation of gasoline, kerosene, etc., from a crude oil, to leave a residual fuel oil or asphaltic bitumen, the process is frequently called topping. Distillation is normally carried out in such a way as to avoid decomposition (cracking); in the case of the higher boiling distillates, such as long residue, this is accomplished by carrying out the distillation under vacuum (which requires a lower temperature). DISTILLATION CURVE Curve made by plotting the percentage of gasoline (or other petroleum product) distilled versus the temperature. DISTRIBUTOR (LIQUID/GAS) A device for distributing a 2 phase flow correctly within a vessel, i.e. encouraging separation. DISULPHIDE

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A compound containing a -S-S- linkage. Such compounds are colourless liquids completely miscible with hydrocarbons and insoluble in water. The lower members, when pure, possess a nauseating sweet odour which is particularly clinging and penetrating. Although disulphides are normal constituents of the lighter distillates, they are also formed as a result of the oxidation of mercaptans. Sour distillates become sweetened in this way. DIVIDEND YIELD Market Price of Shares (cents) Dividend Paid (cents) DOCTOR TREATMENT A process of sweetening sour gasoline’s - by conversion of the mercaptans - by means of a solution of lead oxide in caustic soda, together with sulphur. Not used at NZRC. DOWNCOMER A means of conveying liquid from one tray to the next below in a trayed column. DOWNSTREAM Towards the later end of the process e.g. final blending, product tankage. In the business sense - Marketing of finished products, filling stations etc. DRAW OFF A connection which allows liquid to flow from the bottom of a vessel or to remove the contents from a draw off tray. DRY GAS Natural gas which does not contain liquid hydrocarbons at storage pressure. Also often used for a petroleum gas consisting of no other compounds than inert gases (e.g. hydrogen, nitrogen, etc) and the light hydrocarbons methane, ethane, ethene, propane, propene (sometimes also: hydrogen sulphide). DUAL PURPOSE KEROSENE 33. Created by Ranjit Kumar

An export grade Kero that meets both premium and Avtur specifications.

ECONOMISER Equipment for preheating boiler feed water by use of low grade flue gas. EJECTOR A device that uses the venturi effect to pull a partial vacuum. Usually driven by steam and associated with condensing plant. ELASTOMER A synthetic polymer with rubber-like characteristics. Examples of commercial products are styrene-butadiene rubbers, butyl rubber, chloroprene rubber, nitrile rubber, polyurethane rubber and silicone rubber. ELECTRICAL ISOLATION CERTIFICATE Permit required to isolate or de-isolate any electrical equipment. ELECTROLYSIS Chemical decomposition by the action of an electric current. EMULSION A dispersion of fine droplets of a liquid (the disperse phase) in the bulk of another liquid (the continuous phase) with which it is immiscible. A third substance, the emusifier, is sometimes necessary to keep the droplets dispersed as a stable emulsion. END POINT The point indicating the end of some operation or at which a certain definite change is observed. In titration, this change is frequently a change in colour of an indicator which has been added to the solution, or the disappearance or excess of one of the reactants which is coloured. In the distillation of liquids, such as 34. Created by Ranjit Kumar

gasoline, the end point is the maximum temperature which occurs during the test (F.B.P). ENDOTHERMIC Relating to or designating a reaction which occurs with the absorption of heat, so that the temperature of the reacting bodies is lowered (i.e. heating is required). ENGINE OIL A term applied to oils used for the bearing lubrication of all types of engines, machines, and shafting, and for cylinder lubrication in other than steam engines. EROSION To gradually wear away e.g. Catalyst circulation causes erosion. ETHANE C2H6 A colourless, odourless gas of the methane series. Along with methane one of the main constituents of natural gas. ETHENE The normalised name for ethylene. A hydrocarbon gas and first member of the olefin series. EVACUATION Act of pulling a vacuum on a vessel at atmospheric pressure - thus evacuating the air/gas present. EVAPORATION The conversion of a liquid into vapour, usually by means of heat. EVAPORATOR A vessel which receives the hot discharge from a heating coil, and by a reduction in pressure, flashes off overhead the light products and allows the heavy residue to collect in the bottom. EX SITU REGEN 35. Created by Ranjit Kumar

Where catalyst is removed from a reactor and regenerated elsewhere (usually at a catalyst specialists own plant). EXOTHERMIC Relating to or designating a reaction which occurs with the evolution of heat, so that the temperature of the reacting bodies is raised (i.e. cooling is required). EXPANSION JOINT A joint or coupling designed so as to permit an endwise movement of its parts to compensate for expansion or contraction. EXTRACT The portion of an unrefined petroleum product (often a kerosene or a lubricating oil) resulting from a solvent extraction process and consisting mainly of those components which are best soluble in the solvent. Generally the extract, after removal of the solvent consists largely of aromatic hydrocarbons. EXTRACTION A fractionation process based upon the difference in solubility, in a given solvent, of the various constituents of the mixture to be fractionated. The process is, for example, used in the separation of de-asphalted oil from short residue (see butane de-asphalting). EXTRACTION DEPTH Depth to which DAO may be extracted from short residue on BDU unit - the greater the extraction depth, the higher the DAO yield, although too deep an extraction may affect DAO specification. EXTRACTOR Column in which an extraction process (e.g. BDU) is carried out. EXTRAORDINARY ITEMS Items of expenses or income that are not related to the main activities/operations of the company. EXTREME PRESSURE LUBRICANTS 36. Created by Ranjit Kumar

A term applied to lubricating oils or greases which contain a substance or substances specifically introduced to prevent metal-to-metal contact in the operation of highly loaded gears and bearings. In some cases this is accomplished by the substances reacting with the metal to form a protective film.

F FATIGUE The tendency of a metal to become brittle and fracture under conditions of repeated cyclic stressing at stress levels below its tensile strength. FEED PREPARATION UNIT High vacuum unit to split a long residue into a short residue and waxy distillate fraction with a low metal content; the latter fraction is used as Hydrocracker feed. FEEDSTOCK Stock from which material is taken to be fed (charged) into a process unit. FILTER A porous material on which solid particles are largely caught and retained when a mixture of liquids and solids is passed through it. FILTRATE The liquid which has passed through a filter; the product from a filtration process. FIN FAN See air heat exchanger. FIRE WALL An earth bank or cement wall built around an oil storage tank compound to prevent the spread of the oil in case of fire or 37. Created by Ranjit Kumar

bursting of the tank. Height normally calculated to contain contents of largest tank within compound. FIXED-BED OPERATION A type of operation in which the catalyst remains stationary in the reactor. The catalyst may be regenerated insitu or exsitu periodically. To be contrasted with fluid-bed operation. FLAME ARRESTOR An assembly of perforated plates or screens enclosed in a case and attached to the breather vent on petroleum storage tanks, and on bitumen or sour water gas lines prior to burning the gas in a furnace. FLAMMABLE Capable of being easily set on fire; combustible. FLASH 1. A sudden release in pressure resulting in partial or complete vapourisation. A sudden burst of light; a momentary blaze. FLASH DISTILLATION The process of heating a liquid to a temperature within the boiling range of the liquid which causes the evaporation of part of the liquid. The vapour may then be taken off and condensed. FLASH POINT The lowest temperature under closely specified conditions at which a combustible material will give off sufficient vapour to form an inflammable mixture with air in a standardised vessel. Flash point tests are used to assess the volatilities of petroleum products. FLEXIBLE VOLATILITY INDEX A measure of the volatility of gasoline’s calculated by the formula 38. Created by Ranjit Kumar

RVP +( 0.7 x E70 ) E70 = Evaporation at 70 0C FLOATING HEAD An end of a heat exchanger into which tubes are fitted, constructed to allow for the expansion and contraction of the exchanger tubes. FLOATING ROOF A special tank roof which floats upon the oil. Applied to do away with the vapour space in storage tanks and thus reduce losses by breathing and hazards of explosions. FLOODING In a fractionating column, the filling up with a liquid. FLUE GAS Gas from the combustion of fuel, the heating effect of which has been substantially spent and which is, therefore, discarded to the flue or stack. Its constituents are principally CO2, CO, 02, N2 and H20. FLUID Non rigid substance consisting of particles that move freely amongst themselves (includes particulate, liquids and gases). FLUID BED OPERATION Where catalyst is continually moved from the reactor to a regenerator and back again, as in the continuously regenerated platformer or cat cracker processes. FOAM A preparation designed to smother oil fires. It consists of a solution which, on mixing with water, produces a mass of foam many times the volume of the original liquids. FOAMING

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1. The formation of froth or foam on lubricating oils or other oils as a result of aeration or release of gas dissolved in the oil. 2. The formation of bubbles on the surface of boiled water. The foam may entirely fill the steam space of the boiler or may be of minor depth; in either case, it causes appreciable entrainment of boiler water with steam. 3. Caused in Adip systems by presence of liquid hydrocarbons or fines affecting surface tension of solution. FORCED DRAUGHT Air forced into a furnace by means of a fan or blower to improve combustion (compare induced draught). FRACTION A portion of petroleum separated from other portions in the fractionation of petroleum products. It is often characterised by a particular boiling range. FRACTIONAL CONDENSATION A separation of the components of vapourised oil coming off during distillation by condensing the vapours in stages (partial condensation). The oil of highest boiling point will condense first and may be removed in the liquid stage, allowing the portion still in the vapour state to pass on to the next stage condenser. FRACTIONATING COLUMN An apparatus in which fractionation is carried out. It consists of a vertical cylindrical metal vessel, containing equipment for the proper contacting of flashed liquid and vapour. heat is often supplied at the bottom of the column in a reboiler, whereas heat is withdrawn at the top in a condenser. Heat can also be supplied or withdrawn at intermediate heights of the column, if beneficial to the process (inter-heaters or inter-coolers). The oil to be fractionated is fed into the column at one or more predetermined locations throughout the height of the column. The contacting equipment is formed by fractionating trays in the oil and chemical industry in general, although for some applications various packing materials are used. 40. Created by Ranjit Kumar

FRACTIONATING TRAYS Equipment aimed at promoting contact between vapour and liquid for fractionation. The flow can be of a single type (i.e. vapour and liquid are arranged to use separate aperatures) or of the dual type (i.e. vapour and liquid may use the same aperature). The former type is promoted by the provision of downcomers for the liquid. Various arrangements of downcomers lead to various systems of trays. Analogously there may be different provisions for the vapour passage, again leading to various possibilities of trays. For further information see bubble cap trays, calming section trays, grid trays, sieve trays and valve trays. FRACTIONATION The general name for a physical process of separating a mixture into its constituents, or into groups of these constituents, called fractions. Examples are: absorption, azeotropic distillation, crystallisation, decanting, distillation, extraction, extractive distillation and flotation. FREE ON BOARD (FOB) The unit price at the loading port. FREE WATER Water which is not dissolved (ie not chemically bound in solution) in a fuel or feedstock. FREEZE POINT An important characteristic of aviation fuels. The test for Jet A1 is to cool until solid then reheat, the temperature at which the solid MELTS is called freeze point. FREEZING POINT The temperature at which crystals first appear when a liquid is cooled under specified conditions. FRESH GAS

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In the HYDROCRACKER, Fresh H2 from the reformer to replace H2 used up in the process. Otherwise any imported gas as distinct from recycle gas. FRICTION Resistance to the motion of one surface against another. FUEL AIR RATIO The ratio of the weights of fuel to air supplied to an engine, furnace or boiler at any time. FUEL CELL An electrochemical device to convert chemical energy directly into electricity. It is similar in some respects to a storage battery or a dry cell. Like a battery, the fuel cell produces electricity by a chemical reaction. Unlike a storage battery, however, the fuel cell continues to produce electricity as long as fuel is added. In a fuel cell chemical energy is directly converted to electrical energy by a process that is the reverse of electrolysis. A fuel gas is fed into one or two hollow porous electrodes in a liquid electrolyte whilst oxygen or air is supplied to the other electrode. FUEL GAS Any gas used for heating by combustion. FUEL OIL Any liquid or liquefiable petroleum product burned for the generation of heat in a furnace or firebox, or for the generation of power in an engine, exclusive of oils with a flash point below 100oF. FUNCTIONAL LOGIC SCHEME Diagrams used to show the interaction of plant trips, both cause and effect. FUNCTIONAL LOGIC SYSTEM

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System of plant protection whereby loss of a signal indicates a failure or trip of part of the unit. This trip will then shutdown all or part of the unit. FURNACE That section of the refinery process in which the combustion of fuel and air takes place. FURNACE PASS For more even heat transfer, the product to be heated is usually split into 4 or more individual pipes (passes) and then recombined at the furnace exit.

G GAP 1. In adjacent fractions, the temperature difference between the initial boiling point of the higher boiling fraction and the end point of the lower boiling fraction. Specifically, the term 'gap' is only used when this difference is positive (c.f. overlap). 2. The mid-position where a pair of gap-acting split range controllers are both closed. GAS HOLDER A tank for the storage of gas. It usually floats on a liquid seal, buoyed up by the pressure of the stored gas. GAS OIL Another common name for diesel fuel (A.G.O.) GAS/OIL RATIO The volume of gas at atmospheric pressure produced per unit volume of oil produced (from oil wells). GASOLINE 43. Created by Ranjit Kumar

Light petroleum fraction, with a boiling range between the approximate limits of 30 and 200oC. GAS TURBINE An engine in which gas (as distinct from steam) is directed, under pressure, against a series of turbine blades. The energy contained in the rapidly expanding gas is converted into rotary motion. GATHERING STATION Oilfield installation which receives the production from several wells in its vicinity. It provides facilities to separate the gas and the water, to gauge the production of oil, gas and water, and to transport the oil to the main storage tanks. GEAR OIL A lubricating oil for use in standard transmissions, most types of differential gears, and gears contained in gear cases. GLAND The outer portion of a stuffing box, consisting of a tubular projection which embraces the rod and extends into the bore of the box, thus bearing against the packing. GOVERNOR A device used to control the speed of a turbine, the best known example being the Woodward Governor. GRAVITOMETER Instrument used for measuring changes in the specific gravity of oil flowing in a pipeline. GRID TRAYS Fractionating trays consisting of parallel bars of flat or round section. The flow is essentially of the dual type, but this character may be reduced by the provision of downcomers (see Fractionating trays). GUM 44. Created by Ranjit Kumar

Oxidation of gasoline's may produce a sticky substance known as "gum". When unstable gasoline’s are stored for long periods, the gum content may increase. Gum forming is retarded or prevented by using certain inhibitors, e.g. Topanol.

H HAMER LINE BLIND A spectacle blind-type blanking device which has only 3 retaining bolts, these are a type of wing not. HEADER A common manifold in which a number of pipelines are united. Also used in reference to the U-bend connection between two consecutive tubes in a coil. HEAT CAPACITY Amount of heat per kg per oC change in temperature. HEAT EXCHANGER An apparatus for transferring heat from one fluid to another. Specifically, a piece of equipment having a tubular piping arrangements which affects the transfer of heat from a hot to a relatively cool material by conduction through the tube walls. HEAT OF COMBUSTION The heat created when a substance is burned in oxygen. The calorific, thermal, or heating value of a fuel is the total amount of heat developed by the complete combustion of a unit quantity of fuel; it is reported as calories per gram or Btu per pound. HEATER The furnace-and-tube arrangement which normally furnishes the principal heating element in a processing unit. HI-FI TRAYS 45. Created by Ranjit Kumar

Similar to calming section trays, except there is a greater downcomer area. HIGH VACUUM UNIT A unit for the production of vacuum gas oil and waxy distillate from long residue, by means of distillation at very low pressures, i.e. high vacuum. HORSEPOWER A unit of rate of operation; one mechanical horsepower equals 33,000 ft-lb per minute, or 550 ft-lb per second. This is just one form of Horse Power there are more. HORTON SPHERE A spherical tank used to store volatile liquids under high pressure, e.g. butane. HOT OIL Any oil used for the transfer of heat, as in the 700 Unit. HOT SPOT 1. A finite area in the combustion zone of an engine which remains at a temperature higher than that of the immediate surrounding, thus aggravating detonation or pre ignition. 2. An area on the wall of a vessel or line which is appreciably above normal operating temperature. Often as a result of the deterioration of an internal insulating liner which exposes the line or vessel shell to the temperature of its contents. HUMIDITY A measure of the moisture contained in the atmosphere. HYDRATE A compound formed by the chemical union of water with a molecule of some other substance such as gypsum, from which water may be separated by a simple readjustment of the molecular structure. Gas hydrates, formed from water and, for example 46. Created by Ranjit Kumar

methane, may cause plugging of the tubing and flow lines of gas wells. HYDRATION The addition of water to a double bond, no breakdown of the molecular structure being involved. HYDRAULIC FLUIDS Fluids used in the hydraulic systems of aircraft and industrial equipment etc. HYDROCARBON A compound containing only hydrogen and carbon. The simplest hydrocarbons are gases at ordinary temperatures; but with increasing molecular weight, they change to the liquid form and, finally, to the solid state. They form the principal constituents of petroleum. HYDROCHLORIC ACID A strong mineral acid, HCL. It is also called muriatic acid. HYDROCRACKING A process in which hydrocarbons are converted under hydrogen pressure into products of lower molecular weight, in the presence of an acidic catalyst. HYDRODEALKYLATION A process to remove side-chains on aromatic molecules, either thermally or catalytically, under hydrogen pressure. HYDRODESULPHURIZATION The elimination of sulphur containing molecules in crude’s or distillates by the action of hydrogen under pressure over a catalyst. HYDROGEN

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The lightest of all gases, occurring chiefly in combination with oxygen in water, also in acids, bases, alcohol’s, petroleum and other hydrocarbons. HYDROGEN BLISTERING A form of corrosion. Blistering of steel is caused by trapped molecular hydrogen formed as atomic hydrogen during attack of steel by hydrogen sulphide. HYDROGEN SULPHIDE A compound of hydrogen and sulphur, specifically the monosulphide; a colourless, flammable, poisonous gas, H2S, having a disagreeable odour; also called sulphureted hydrogen. HYDROGENATION The filling of the "free" places in unsaturated structures by hydrogen atoms. The chemical addition of hydrogen to a material. In non-destructive hydrogenation, hydrogen is added to a molecule only if, and where, unsaturation with respect to hydrogen exists. In destructive hydrogenation, the operation is carried out under conditions which result in rupture of some of the hydrocarbon chains (cracking); hydrogen is added where the chain breaks have occurred. This process is known as hydrocracking. HYDROLYSIS The decomposition of a molecular structure by the action of water. A chemical decomposition in which a compound is broken up and resolved into other compounds by reaction with water. In many cases, it is induced by the presence of a small amount of dilute acid. HYDROMETER A graduated instrument for determining the gravity of liquids, usually made of hollow glass and weighted at one end so as to float upright. On immersion, the lighter the liquid, the lower the instrument sinks because the buoyancy force is less. Some hydrometers are marked to read percentage of constituent, or some other property related to gravity. The instruments used in measuring petroleum products usually read degress API or specific gravity directly. 48. Created by Ranjit Kumar

HYDROSTATIC HEAD The pressure exerted by a column of fluid, equalling the height of the column times the fluid density times the acceleration of gravity. An expression of the pressure existing at a certain point, in terms of weight of a superimposed column of fluid. HYDROSTATIC TEST A pressure test using water to check the reliability of equipment prior to being bought into service. HYDROTREATING A vapour phase process used to treat petroleum fractions C. The process involves passage over a fixed bed°boiling up to approximately 250 of catalyst (usually prepared by depositing the metals COBALT and MOLYBDENUM on an alumina base) in a hydrogen atmosphere. The process achieves: 1. Hydrogenation of the sulphurous contaminants in the feedstock to hydrogen sulphide. 2. Saturation of unsaturated component compounds such as olefins.

I IGNITION POINT The point or temperature at which a substance takes fire. IGNITION QUALITY A measure of the ignition delay of a fuel in a diesel engine. IMMISCIBLE Not capable of mixing; tending to form two layers, e.g. oil and water. INCOMPATIBLE 49. Created by Ranjit Kumar

Applied to a substance which, for chemical, physical, or physiological reasons, cannot be mixed with another without changing its nature or affect. INDIGENOUS FEEDSTOCK Local (i.e. NZ) crude’s or condensates e.g. Maui, Kapuni etc. INDUCED DRAUGHT Air drawn into a furnace by means of a fan to improve combustion (compare forced draught). INERT ENTRY Specialised entry into a vessel under N2 atmosphere, by use of B.A. and special safety precautions. Used e.g. in hydrocracker catalyst change operation. INERT GAS Nitrogen on the refinery, scrubbed flue gas on the tankers. Used for air (oxygen) exclusion to reduce fire/explosion risk. INERT FILLER Non reactive packing/support material, e.g. ceramics, stainless steel etc. INFLAMMABLE Very flammable - not to be confused with non-flammable. INHIBITOR A substance, the presence of which in small amounts in a product prevents or retards undesirable changes in the quality of the product, or in the condition of the equipment in which the product is used. In general, the essential function of inhibitors is to prevent or retard oxidation. Examples of uses include the delaying of gum formation in stored gasoline’s and of colour change in lubricating oils; also the prevention of corrosion, e.g. rust prevention by inhibitors in turbine oils and fuels. INITIAL BOILING POINT 50. Created by Ranjit Kumar

According to ASTM Method D 86 the recorded temperature when the first drop of liquid falls from the end of the condenser. INJECTOR A mechanism which may be used in different forms for spraying fuel oil into the combustion chamber, or for feeding water into steam boilers. IN-LINE BLENDING A system in which all components are pumped simultaneously into a common discharge pipe (header) at rates of flow corresponding to the required proportions, the rates of flow being controlled. Blending takes place in the lines between the header and the storage tank into which the blend is discharged. INORGANIC Pertaining to substances not organic, nonliving, i.e. which are not carbon compounds, with the possible exception of the oxides and sulphides of carbon. INSITU REGEN Catalyst regeneration carried out within the reactor. Carbon is burned off under controlled conditions of heat/air. Less effective, but cheaper and usually quicker than ex-situ. INSTITUTE OF PETROLEUM The organisation in Great Britain primarily responsible for the advancement of the study of petroleum and its allied products in all their aspects. It is the recognised British standardisation authority for methods of testing petroleum products. INTERCEPTOR Equipment to remove oil from water either for process separation or pollution control. Weir, parallel and tilted plate types are used. INTERNAL-COMBUSTION ENGINE An engine which operates by means of combustion of a fuel within its cylinder. 51. Created by Ranjit Kumar

ION EXCHANGE RESINS Preparation used in water softening - Anion and Cation resins are used. ISOLATE Any means of positive separation from a risk source:1. To electrically disconnect. 2. To valve/spade isolate a piece of linework/equipment. ISOMER Two substances composed of equal amounts of the same elements but differing in properties owing to variation in structure are called isomers. ISOMERISATION The conversion of a compound into its isomer. For example, butane may be converted into isobutane. A reaction which alters the fundamental arrangement of the atoms in the molecule without adding or removing anything from the original compound. In the petroleum industry, straight-chain hydrocarbons are converted catalytically to branched-chain hydrocarbons of substantially higher octane number by isomerisation. ISO-OCTANE C8H18 (2,2,4-TRIMETHYLPENTANE) A colourless liquid used with n-heptane to prepare standard mixtures to determine anti-knock properties of gasoline. ISOTOPE Any one of a number of atomic species differing in atomic weight but having the same atomic number. Used in some Refinery instruments and for radiography. J JET ENGINE (see also Gas Turbine) 52. Created by Ranjit Kumar

An engine which converts fuel and air into a fast-moving stream of hot gases which effect propulsion of the device of which the engine is a part. JET FUEL Fuel meeting the required properties for use in jet engines and aircraft turbine engines. It is subject to intense testing and quality control as laid down in DERD and AFQRJOS documents internationally.

K KELVIN The unit used as the Absolute temperature scale, i.e. zero Kelvin is absolute zero, 273K is 0oC. The Kelvin degree has the same dimensions as the Celsius degree. The o symbol is not used on the Kelvin scale. KEROSENE Any petroleum product with a boiling range between the approximate limits of 140 oC and 270oC which satisfies certain quality requirements (for lamp oil or jet fuel). KETTLE REBOILER A reboiler with facilities for separation of liquid and vapour. KNOCK Related to internal combustion engines the noise associated with detonation of a portion of the fuel-air mixture in a cylinder ahead of the advancing flame front. KNOCKOUT (DRUM OR VESSEL) A vessel, constructed with baffles, through which a mixture of gas and liquid is passed to disengage one from the other. As the mixture comes in contact with the baffles, the impact frees the gases and allows them to pass overhead; the heavier substance falls to the bottom of the drum. 53. Created by Ranjit Kumar

LAGGING A covering to retain heat, such as mineral wool wrapped on steam pipes. LATENT HEAT Heat required for a change of state without a change of temperature. 1. The latent heat of fusion, or the amount of heat necessary to change a unit mass of solid into a liquid without change of temperature. 2. The latent heat of vapourisation, or the amount of heat necessary to change a unit mass of liquid into vapour without change of temperature. The latent heat of condensation. Effectively the opposite of 2 (above). LEAD Industry parlance for the motor fuel anti-knock additive compounds tetraethyl-lead, tetramethyl-lead, or for other organometallic lead anti-knock compounds. Not used in NZ. LEAD ACETATE TEST A method of detecting the presence of hydrogen sulphide in a sample using lead acetate paper, which will change from white to brown upon detection. LEAD SUSCEPTIBILITY Ability of gasoline’s to respond to the addition of tetramethyl-lead, or other organometallic lead anti-knock compounds, as reflected in the increase of anti-knock quality (octane number) with increase in lead content. LEADED GASOLINE 54. Created by Ranjit Kumar

Refers to gasoline containing tetramethyl-lead or other organometallic lead anti-knock compounds. Not used in NZ. LINEAR PROGRAMME (LP) A mathematical representation of an operation which can be optimised according to a set of economic criteria. LIQUEFIED NATURAL GAS (LNG) Natural Gas can be liquefied, e.g. at atmospheric pressure by cooling to about - 160° C (-256oF). LIQUEFIED PETROLEUM GAS (LPG) of the gaseous hydrocarbons, propane and the butanes can be liquefied under relatively low pressure and at ambient temperature and are then known as liquefied petroleum gas. Light hydrocarbon material, gaseous at atmospheric temperature and pressure, held in the liquid state by pressure to facilitate storage, transport and handling. Commercial liquefied gas consists essentially of propane, butane, or mixtures thereof. LIQUID PHASE The term describing a product or substance when in the form of a liquid. LIQUID SEAL A quantity of liquid used to prevent the emission of a gas through an orifice. To be completely effective the hydrostatic head exerted by the liquid must be greater than the pressure of the gas and the gas must be insoluble in the liquid. LITRE The primary standard of capacity in the metric system, equal to the volume of C, and under°one kilogram of pure water at maximum density, at approximately 4 normal atmospheric pressure. LIVE STEAM

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As contrasted to exhaust steam, steam coming directly from a boiler before being utilised for power or heat. LOAD-ON-TOP SYSTEM System of cleaning the tanks of a crude oil tanker by collecting washings from each tank in one tank, allowing the water to separate from the oil, then discharging the water overboard, leaving the oil residues in the tank. The next crude oil cargo is loaded on top of the residues. LOADING RACK A structure built alongside railroad tracks or at road depots for the purpose of loading tank cars or road tankers with products. LOGIC See functional logic. LONG RESIDUE The residue resulting from the atmospheric distillation of crude oil. LOST TIME ACCIDENT (LTI) Any work injury that results in the worker being unable to recommence work on the day after the injury. LOWER EXPLOSIVE LIMIT Leanest mixture that will explode. A greater air: hydrocarbon ratio will not ignite. LUBOIL Lubricating oil LUBRICANT A substance, especially oil, grease, or a solid such as graphite, which may be interposed between moving parts of machinery, thus reducing friction by preventing contact between the bearing surfaces. The lubricant has an important function in removing heat and dirt from the region of the bearing surfaces. 56. Created by Ranjit Kumar

LUBRICATING OIL A fluid lubricant used to reduce friction between bearing surfaces. Petroleum lubricating oils may be produced either from distillates or residues; amounts of other substances, known as additives, may be added to impart or improve certain required properties. LUBRICATION The state of being lubricated, or the act of applying lubricating substances which are capable of reducing friction between and removing heat from moving mechanical parts.

M MANIFOLD A piping arrangement which allows one stream of liquid or gas to be divided into two or more streams, or which allows several streams to be collected into one. MANOMETER An instrument for measuring the expansion or the expansive power of gases or vapours; a pressure gauge or vacuum gauge. MASS SPECTROMETER A device for analysing a substance in terms of the mass-to-charge ratios of its constituents. It is so designed that the beam constituents of a given-mass-to-charge ratio are focused on an electrode and detected or measured electrically. The mass spectrum shows the distribution in mass or the mass-to-charge ratio of ionised atoms, molecules, or molecular fragments. MELTING POINT Temperature at which a solid substance melts or fuses. For asphalt, the melting point is defined as the temperature at which the asphalt is soft enough to permit a steel ball to drop through a disk of asphalt supported in a ring suspended in water (ring-and-ball method). The grease melting point is determined by 57. Created by Ranjit Kumar

placing a small amount of the grease on the bulb of a thermometer and heating in hot air until the grease begins to run off. METHANATOR Part of the reformer process that converts unwanted carbon oxides to methane which is more acceptable to the hydrocracker. METHANE CH4 A light, odourless inflammable gas. It is the chief constituent of natural gas. It is also often produced by a partial decay of plants in swamps (marsh gas), so that its occurrence is commonly misinterpreted by the layman as an indication of the presence of petroleum. METHANE SERIES A homologous series of open-chain saturated hydrocarbons of the general formula CnH2n+2 of which methane (CH4) is the first member of the type; generally called the paraffins. METHANOL Methylalcohol, CH3OH. The first member of the class of organic compounds C. Methanol is inflammable and°known as alcohols. It is a liquid boiling at 66 poisonous. It is used in the production of synthetic gasoline - see synfuel. METHYL CHLOROFORM Used as a catalyst promotor in the platformer. METHYL TERTIARY BUTYL ETHER (MTBE) An oxygenated compound which can be used as a blending compound in gasoline to boost octane. METRIC SYSTEM A system of weights and measures derived from the metre. The system includes: measures of length, wherein the metre is the unit, measures of surface, wherein the square metre is the unit, measures of capacity, wherein the litre is the unit, and weights, wherein the gram is the unit. 58. Created by Ranjit Kumar

MIDDLE DISTILLATE One of the distillates obtained between kerosine and lubricating oil fractions in the refining processes. These include light fuel oils and diesel fuel. MINERAL OIL Generally speaking, this term refers to a wide range of products derived from mineral substances. MINIMUM STOP A setting used to restrict the closure of a control valve. There are two ways of achieving this:1. Mechanical, by use of a collar or nut on the spindle, diaphragm. 2. Pneumatically, by restricting the minimum air signal from the control instrument. MISCIBLE Capable of being mixed (stability and uniformity throughout the mixture are usually inferred). MIXED BASE CRUDE A crude oil which is a mixture of paraffin - and naphthene-base crude. MIXER Device used for mixing partially im-miscible liquids in process plant or to prevent layering in tanks - a propeller or jet mixture may be used. MIXING VALVE A valve which creates turbulence within a pipe to effect mixing of the materials flowing through the pipe. MIXTURE

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The intermingling of two or more substances, each retaining its original properties. MOLE PERCENT An expression of the percent composition of a mixture in terms of moles. The relative numbers of moles are computed by dividing the numbers of units of weight of the individual constituents by their respective molecular weights. MOLECULAR WEIGHT The sum of the atomic weights of the atoms composing a molecule. MOLECULE The smallest portion of an element or a compound which retains chemical identify with the same particular substance en masse, e.g. unit of water. MOTOR OCTANE NUMBER (MON) The Octane number of a Motor Gasoline determined in a special laboratory test engine under high "engine-severity" conditions, giving a rough measure of the high-speed knock properties of the gasoline. MOTORISED VALVE A valve incorporated in automatic control systems to regulate the rate of flow of material through a section of pipe. It is actuated either hydraulically, electrically, from a control instrument. MULTIGRADE OIL One of the multi-viscosity number oils in which one oil combines three SAE viscosity number grades. For example, multigrade SAE 10W-30 grade may be used where SAE 10W, SAE 20-20W, or SAE 30 grades specified. Multi-grade oils are usually made to meet the requirements of API Services MS, DG, and DM. They have been made possible by improved refining processes and the use of improved additives. MULTISTAGE PUMP 60. Created by Ranjit Kumar

Pump with more than one impeller. Generally used in high pressure/medium flow applications.

N NAPHTHA Naphtha’s are straight-run gasoline fractions boiling below kerosene. Being generally unsuitable as a blending component for premium gasoline’s, they are used as a feedstock for Platforming. Other important outlets for naphtha’s are their use as chemical feedstock (e.g. ethylene manufacture) and as feedstock for town gas manufacture. NAPHTHENE A class of saturated cyclic hydrocarbons of the general formula CnH2N. One of a group of cyclic hydrocarbons, also termed cycloparaffins or cycloalkanes. Polycyclic members are found in the higher boiling fractions of crude oil. NAPHTHENIC ACID Naturally occurring acidic compounds commonly found in Naphthenic crude’s. NAPHTHENIC CRUDE Crude oil containing a relatively large percentage of naphthene. An oil obtained from a Naphthenic crude is said to be a naphthene base oil. Lubricating oils made from such crude’s are normally distinguished from similar oils made from paraffinic crude’s (both oils equally well refined) by lower gravity, lower carbon content and pour point, and lower rating viscosity index. NATURAL DRAUGHT A flow of air into the combustion chamber of a heater which is neither induced nor forced but derives solely from the fact that the pressure inside the heater is lower than that of the ambient atmosphere (due to effect of stack). NATURAL GAS 61. Created by Ranjit Kumar

Naturally occurring mixtures of hydrocarbon gases and vapours, the more important of which are methane, ethane, propane, butane, pentane, and hexane. The gas which occurs naturally with crude oils, but also in reservoirs which contain only a few heavier constituents. It consists mainly of the lighter paraffin hydrocarbons. Natural gas is usually classified as wet or dry, depending on whether the proportions of gasoline constituents which it contains are large or small. Most gas reaches the surface through the tubing, but in some pumping wells it is taken off at the top of the casing (casinghead gas). NATURAL GASOLINE Gasoline extracted from wet natural gas, consisting of butane, pentane and heavier hydrocarbons. After stabilisation - the removal of the lighter components - the gasoline is suitable for blending into motor gasoline. NET ASSET BACKING/SHARE Shareholders' Investment Number of shares NET PROFIT AFTER TAX Income from all sources less operating costs, depreciation and tax. NET PROFIT BEFORE TAX Income from all sources less operating costs and depreciation. NEUTRAL Neither acid nor alkaline. NEUTRON An uncharged particle having the mass of the proton. Generally, together with the protons, neutrons make up the nucleus of atoms. NITROGEN

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Element of atomic number 7, in group V of the periodic system; colourless, odourless, tasteless diatomic gas constituting approximately four-fifths of the air; chemically rather inert; soluble in water. Derived from liquid air by fractional distillation. Used extensively in refineries for inerting process plants (air exclusion). NITROGEN BASE A compound, such as amine, which may be considered a substitution product of ammonia; a compound containing trivalent nitrogen, capable, like ammonia, of combining with acids in the formation of salts containing pentavalent nitrogen. NON-ASSOCIATED NATURAL GAS Gas accumulations which exist independently of any oil accumulation. NON CUSTODY TRANSFER TANKS Tanks which receive products from internal sources or deliver products to internal sources. NORMALISE Correction made to a calculated figure (e.g. WABT) to allow for the effect of other variables.

O OCTANE The octane number of a fuel is a number equal to the percentage by volume of iso-octane in a mixture of iso-octane and normal heptane having the same resistance to detonation as the fuel under consideration in a special test engine. It is a measure of anti-knock value of a gasoline and, in the case of the special test engine, the higher the octane number the higher the anti-knock quality of the gasoline. OIL RING 63. Created by Ranjit Kumar

A loose ring, the inner surface of which rides a shaft or journal causing the ring to rotate. The ring dips into a reservoir of lubricant, from which it carries the lubricant to the top of the shaft for distribution to a bearing. Also the ring on an internal-combustion engine piston which controls the lubrication of the piston and cylinder walls, as contrasted to the compression rings. OIL SHALE A compacted sedimentary rock consisting mainly of consolidated muds and clays and containing organic matter which yields oil when destructively distilled but not appreciably when extracted with the ordinary solvents for petroleum. OLEFINS A class of unsaturated, non-cyclic, aliphatic hydrocarbons of the general formula CnH2n (mono-olefins). Ethene is the parent member of the group. Not very abundant in crude oils. ONCE-THROUGH An adjective describing: 1. A condition or operation in which no portion of the product is recycled. 2. The products from such an operation. ON STREAM The length of time a unit is in actual production. ORGANIC Designation for a branch of chemistry; treating, in general, of the compounds produced in plants and animals, or of carbon-hydrogen compounds of synthetic origin; contrasted with inorganic. ORIFICE METER An instrument which measures the flow through a pipe by use of the difference in pressure on the upstream and downstream sides of an orifice plate. 64. Created by Ranjit Kumar

ORIFICE PLATE A device for restricting the flow through a pipe. OSMOSIS Migration of ions or species from an area of high concentration to one of lower concentration. OUTPUT The pneumatic or electronic control signal sent from the control instrument to the valve. OVERHEADS In a distilling operation, that portion of the charge which is vapourised and removed as the total stream from the top of the column. OVERLAP In adjacent fractions, the temperature difference between the initial boiling point of the higher boiling fraction and the end point of the lower boiling fraction. Specifically the term 'overlap' is only used when this difference is negative (cf. GAP). OXIDATION The reaction of oxygen with a molecule that may or may not already contain oxygen. Oxidation may be partial, resulting in the incorporation of oxygen into the molecule or in the elimination of hydrogen from it, or it may be complete, forming carbon dioxide and water (combustion) - contrast with reduction. OXIDIZING FLAME Term applied to a flame in which there is an excess of air or oxygen.

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A fractionating or absorber tower which is filled with small objects (packing) to effect an intimate contact between rising vapour and falling liquid. PACKING 1. Typically PALL or RASCHIG rings of stainless steel or ceramic as used in a packed tower. May be DUMPED or STRUCTURED - The latter being assembled rather than tipped in which results in lower p.d. and increased vapour/liquid contact thus greater efficiency. 2. Any material used to pack, as a layer of material put between the surfaces of a flange or used in a stuffing box to prevent leakage. PARAFFIN-BASE CRUDE Crude oils which contain paraffin wax but little or no asphaltic matter. PARAFFINS Straight(N) or branched (ISO) open chain saturated hydrocarbons. PARAFFIN WAX Wax of solid consistency having a relatively pronounced crystalline structure, extracted from certain distillates of petroleum, shale oil etc. Refined paraffin wax has a very low oil content; it is white with some degree of translucency, almost tasteless and odourless and slightly greasy to the touch. PARTIAL CONDENSER A heat exchanger, which condenses part of a vapour stream. For example, partial condensers are used to condense the reflux liquid stream and liquid top product from the overhead vapours of a fractionation column. PARTIAL PRESSURE Partial pressure of a component of a mixture in vapour-liquid equilibrium is that part of the pressure which is contributed by that component. 66. Created by Ranjit Kumar

PENETRATION Consistency, expressed as the distance that a standard needle or cone penetrates vertically into a sample of the material under known conditions of loading, time and temperature. A measure of the hardness and consistency of asphaltic bitumen by which a weighted special cone or needle will penetrate the C°sample in five seconds, the temperature, unless otherwise stated, being 25 F).° (77 PERMIT TO WORK A permit raised for any job that is carried out in the “restricted area”

PETROL Term commonly used for motor spirit or gasoline. PETROLEUM A material occurring naturally in the earth, predominantly composed of mixtures of chemical compounds of carbon and hydrogen with or without other nonmetallic elements such as sulphur, oxygen, nitrogen, etc. Petroleum may contain, or be composed of, such compounds in the gaseous, liquid, and/or solid state, depending on the nature of these compounds and the existing conditions of temperature and pressure. PETROLEUM NAPHTHA A generic term applied to refined, partly refined, or unrefined petroleum products and liquid products of natural gas, not less than 10 percent of which C), and not less than 95 percent of which distill below°F (175°distill below 347 C) when subjected to distillation in accordance with ASTM method°F (249°464 D86. PETROLEUM SPIRITS Refined petroleum distillates with volatility, flash point, and other properties making them suitable as thinners and solvents in paints, varnishes, and similar products. 67. Created by Ranjit Kumar

PETROLEUM WAX See crude wax. PHENOL Hydroxyl derivative of aromatic hydrocarbons. Found in effluent water - occurs from contact with certain crude’s. PHOSPHATE 1. A salt of phosphoric acid. 2. At NZRC - generally used to refer to TRISODIUM PHOSPHATE, an alkaline water treatment chemical. Na3Po4 pH VALUE The logarithm of the reciprocal of the hydrogen ion concentration. This indicates the acid or alkaline condition of a substance, pure water and neutral solutions having a pH of 7. Acid solutions have a pH less than 7; alkaline solutions, a pH greater than 7. PIG Device sent down pipelines for various purposes. Types include Polypigs, swabs, brush pigs, go-devils and linelogs. PILOT PLANT A small version of the full-scale plant in which a laboratory pursues development work, after bench-scale investigation of a new process has shown promise. PIPELINE A line of pipe with pumping machinery and apparatus for conveying a liquid or gas. PISTON In engines and pumps, a reciprocating device in a cylinder or tube which receives pressure from, or delivers pressure to, a fluid. PISTON RING 68. Created by Ranjit Kumar

A ring used to maintain a gas tight seal between the piston and the cylinder and to control cylinder wall lubrication. PITTING Irregular corrosion in metalwork. PLATFORMING A reforming process which makes use of a catalyst containing platinum and excess of hydrogen. Catalytic reforming of straight-run heavy gasoline (Naphtha) produces a product which is richer in aromatics and branched-chain paraffins and poorer in naphthenes and straight chain paraffins. The hydrogen produced in this process is used for hydrodesulphurisation and hydrocracking. POLYELECTROLYTE Substance used to encourage flocculation in water treatment units. POLYMER A substance produced from another by polymerisation, i.e. the combination of a number of identical molecules to form a larger one. PREHEAT To heat, previous to some treatment; as an oil to be subsequently distilled, or as a body of gas or oil to be used as fuel. PREHEATER Any form of apparatus in which heat is applied to a material prior to its introduction into the main heating apparatus. The application of heat is usually accomplished by means of hot streams which have to be cooled and whose heat would otherwise be wasted. (See also HEAT EXCHANGER). PRESSURE The force or thrust exerted on a surface, normally expressed as force per unit area. Pressure is exerted in all directions in a 69. Created by Ranjit Kumar

system. Common examples; air pressure in a tyre, or water pressure at some depth in the ocean. PRESSURE DROP The decrease in pressure due to friction, which occurs when a liquid or gas passes through a pipe, vessel, or other piece of equipment. PRESULPHIDE To add sulphur (as DMDS or CS2) in order to initially activate a catalyst by changing the oxide sites to sulphides. PRIMARY A term used to describe the structure of certain classes of organic compounds, such as alcohol’s and amines. For example, a primary compound is one in which one hydrogen atom in the carbinol or amino groups is replaced by a univalent hydrocarbon radical. PRIMARY AIR The air required for combustion in a furnace which is mixed with the fuel (gas, oil, pulverised coal, etc.) in and through the burner (c.f. Secondary Air). PRIMARY PROCESS A process based on physical separation, e.g. Fractionation, gravity separation. PRIME MOVER Any machine capable of producing power to do work. PROCESS INTEGRATION A term denoting the selection and arrangement of refinery processes and the optimum use of the heat contents of the various plant streams. PROMOTER

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A substance which may considerably increase the activity of a usercatalyst. For example the catalytic action of iron is greatly increased when the catalyst contains a small amount of oxides of aluminium or silicon etc., e.g. C1- on Platformer and F- on hydrocracking catalysts. PROPANE C3H8 A hydrocarbon of the paraffin series used for heating, welding and metal cutting. At ambient temperature it can be stored under pressure as a liquid. PROPYLENE C3H6 A hydrocarbon of the olefin series. Important base material for the chemical industry. Propylene is used to make iso-propanol, polypropylenes, plasticisers and glycol’s. PUKING The foaming and rising of oil to the extent that part of the liquid is driven out of the vessel through the vapour line. (See also SURGE). PURGING The removal of one fluid from a vessel or plant by introduction and subsequent evacuation of a second fluid. A common usage of this operation is in the removal of hydrocarbon vapours or air from a plant by flushing with nitrogen. PYROPHORIC Takes fire spontaneously upon contact with air. Certain forms of iron sulphide exhibit this tendency. (Pyrophoric iron).

Q QUENCH To suddenly cool hot material discharging e.g. into a vacuum column, by injecting cool oil into the base; its purpose is to check the cracking reaction quickly to avoid coking. 71. Created by Ranjit Kumar

QUENCH GAS Cool gas injected between the hydrocracker reactor beds used to control reaction temperature. QUENCHING OILS Specially refined high-flash mineral oils used for hardening alloy steels. RADIANT ENERGY Energy sent out or emitted by rays or waves.

R RADIANT SECTION Section of a furnace exposed to the actual combustion of the fuel. RADIATION The act of emitting energy, particularly rays of light or heat. RADICAL In chemistry, a group of atoms whose affinity for one another is so strong that, in chemical reactions, the group acts as a single atom, and is replaced or introduced into a new compound without rearrangement of the atoms bound together in the radical. It can never exist alone as a separate compound. REACTION Any chemical change; the transformation of one or more molecules into other molecules. REACTION TIME The interval during which the material being processed experiences chemical change. REACTOR 72. Created by Ranjit Kumar

Term applied to the part of a plant where a chemical reaction takes place. REBOILER A special type of heat exchanger for the supply of heat to the bottom of fractionating columns. RECIPROCATING COMPRESSOR A displacement compressor relying on forward and backward piston movement. RECIPROCATING PUMP A positive displacement pump consisting of a plunger or a piston moving back and forth within a cylinder(s). With each stroke of the plunger or piston, a definite volume of liquid is drawn in through the suction valve(s) and subsequently pushed out through the discharge valves(s). RECYCLE GAS Gas fed back from a later stage of process (usually from the separators) to the early stage. Usually impure and heavy. RECYCLE OIL Oil recycled from a later stage of the process to an earlier one. HCU second stage feed is recycled from the HCU fractionator and consists of insufficiently cracked material (i.e. heavier than gas oil). RECYCLE RATIO The quantity of recycle stock relative to the quantity of fresh feed. The units of quantity in this relationship vary with the plant concerned. See also combined feed ratio. RECYCLING a) The maintenance of reservoir pressure through re-injection into the reservoir of the produced gas, after extraction of the condensate in a gas plant. 73. Created by Ranjit Kumar

b) Continuously feeding back part of a substance obtained or used in a process for further processing or use. REDUCTION The removal of oxygen - or addition of Hydrogen to a compound. Effectively the opposite of oxidation. REFINERS MARGIN - GROSS The difference in value between the product value ex refinery and landed value of feedstock and blendstock. REFINERS MARGIN - NET The gross refiners margin less fixed and variable cost of refining. REFINERY A plant, with all its included equipment, for manufacturing finished or semi-finished products from crude oil. REFINERY FUEL AND LOSS The difference in intake and output due to the amount used as fuel and lost through tank breathing etc. REFINING The separation of crude oil into its component parts, and the manufacture therefrom of products needed for the market. Important processes in refining are distillation, cracking, chemical treating, and solvent extraction. REFLUX A part (if the top product is in the liquid state) or all (if the top product is the vapour phase) of the condensed top vapour of a fractionating column, which is returned to the top of the column. The purpose is to create an extra downward flow of liquid; if properly applied this liquid acts as an absorbing agent for the relatively heavy components which are thus rejected from the top product. REFLUX CONDENSER 74. Created by Ranjit Kumar

A condenser which constantly condenses vapours and returns liquid to the original distilling unit or to lower levels of a fractionating tower. REFLUX RATIO 1. The quantity of reflux per unit quantity of distillate removed from the process as a product (forward flow). 2. For design purposes, the ratio of liquid reflux to vapour at any given point in a fractionating column. Values may range from zero to unity. REFORMING 1. See catalytic reforming, Platforming. 2. Process for the manufacture of hydrogen from steam and light hydrocarbons. REFRACTORY 1. Any material not easily affected by heat, such as firebrick. 2. Difficult to decompose, for example, in cracking gas oil to produce gasoline. REFRACTORY BRICK A brick which is used as a lining for the interior of fireboxes in furnaces and boilers. Refractory brick is constructed so that it can withstand very high temperatures, but it is not a very good insulator. REGENERATION 1. The process of restoring a material to its original strength or properties. 2. In a catalytic process, the reactivation of the catalyst, usually done by burning off the coke deposits under carefully controlled conditions of temperature and oxygen content of the regeneration gas stream. May be done in situ or ex situ. REGENERATOR 75. Created by Ranjit Kumar

Term applied to the part of a catalytic cracking unit or continuously regenerable platformer (CCR) where the spent catalyst is regenerated by burning off the coke. REID VAPOUR PRESSURE (RVP) The pressure caused by the vapourised part of a liquid and the enclosed air and water vapour, as measured under standardised conditions in standardised apparatus: the result is given in Kilo pascals at 37.8oC, although normally reported simply as "RVP in kPa". There is no simple relation between the RVP and the true vapour pressure of the liquid. RVP gives some indication of the volatility of a liquid, e.g. gasoline. Lower in summer & higher in winter. RELIEF VALVE A spring loaded valve fitted on any piece of equipment or plant where normal operating pressures are above atmospheric. This type of valve automatically opens, thus relieving internal pressure when the latter exceeds the maximum permissible level. RERUNNING The distillation of an oil which has already been distilled. Necessary when a finished batch has been put off grade for any reason. RESIDUE The heavy residual liquid from the atmospheric distillation of crude oil is called long residue. If such residue if further distilled under vacuum a still heavier residual liquid results, which is called short residue.

RESIN Organic compounds produced by polymerisation. 1. Water treatment resins are used for water softening. With a very large surface area, liken to a sponge.

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2. Epoxy and polyester resins of various types are used as fillers, adhesives and coatings. RETAINED EARNINGS Accumulated profits not distributed to shareholders. RICH ADIP Adip containing dissolved H2S. RING COMPOUNDS Organic compounds in which the atoms of a molecule are arranged so as to form at least one closed ring, for example, naphthenes and aromatics. Also called cyclic compounds. RISER 1. That portion of the bubble plate assembly which channels the vapour and causes it to flow upward to escape through the liquid. 2. Fixed vertical line used to get fire water to high levels. ROCKET FUEL Propellant consisting of two components, oxidiser and fuel, which react to give gaeous products and release energy. Rocket fuels are compared on the basis of specific impulse, which means the pounds of thrust produced per pound of fuel burned per second. Rocket fuels may be liquids or solids. In the latter case, the two components must be intimately premixed. In some instances the liquid system may be a single liquid, in which case it is called a mono-propellant. ROTAMETER Simple flow gauge utilising a ball or float in a tapered graduated tube. The greater the flow, the more it raises the ball up the tube. ROTARY PUMP A positive displacement pump used mainly to pump liquids which are either too viscous or too difficult to obtain suction with a centrifugal pump. There are many types of rotary pump designs. 77. Created by Ranjit Kumar

One of the most common is the gear type, in which two gears mesh and rotate toward each other within a very close-fitting casing. The liquid is trapped between the gear teeth and the casing and is carried around to the discharge side of the pump. The meshing gear teeth prevent the liquid from returning to the suction side. RUNDOWN TANK One of the tanks in which are received the condensates from the stills, agitators, or other refinery equipment, and from which the distillates are pumped to larger tanks known as work tanks or storage tanks. Rundown tanks are also known as "pans" or receiving tanks. If the condensates were received directly into the large storage tanks, possible puking of a still could unnecessarily contaminate a large quantity of distillate.

S SAE CLASSIFICATION The SAE devised a system for the classification of motor oils and transmission oils. It is based on the viscosity at 0 or 100oC. Motor oils are on the scale 5W - 50 and transmission oils are 80-250. SAFEGUARDING Total procedure for safety proofing plant. Includes relief systems, functional logic and emergency procedures. SALT A compound in which a metal or other positive ion exists in place of the hydrogen of an acid (e.g. sodium chloride, in which sodium replaces the hydrogen of hydrochloric acid), formed:1. By direct replacement of the acid hydrogen with a metal; 2. By neutralisation of the acid with an appropriate alkali; or 3. By double decomposition. SAMPLE 78. Created by Ranjit Kumar

Sample of a process flow, tank etc. taken for laboratory analysis. SATURATED HYDROCARBON A hydrocarbon of such molecular structure that all adjacent carbon atoms are connected by not more than one valence or bond; or, diagrammatically as follows: C-C. Each valence not taken up by adjacent carbon atoms connects with a hydrogen atom. SATURATION TEMPERATURE Of steam - the temperature at a given pressure, at which steam exists in conjunction with water e.g. 100oC at atmospheric pressure. SCHEDULING The day to day planning of refinery operations to meet long term programmes. SEAL A device used to seal the contents of a pump/compressor from the atmosphere. Occasionally more explosive and complex then the pump itself. SECONDARY AIR The air which provides the oxygen necessary for the complete combustion of fuel (gas, oil, powdered coal, etc.) and which was not provided by the burner in the form of primary air. SECONDARY PROCESS A process based on a chemical change, e.g. Hydrocracking, Platforming, usually catalysed. SEIZE To stick or fail to function, as in engine bearings, because of expansion, caused by heat, friction, or scoring. Also called "freeze". SENSIBLE HEAT 79. Created by Ranjit Kumar

The heat added to, or taken from, a body when its temperature is changed. Note that no change in stage of the body (e.g. solid to liquid) is involved, c.f. latent Heat. SEPARATOR 1. An apparatus in which heavy liquid impurities are separated from oil. 2. The part of a distilling apparatus in which a partial separation of the vapours is effected by means of contact with cooling surfaces. SEPARATION INDEX A measure of the degree of separation between components in a distillation column SEPARATION PROCESSES Manufacturing processes based on differences in the physical properties of the components of a mixture. See Fractionation, Primary Process. SETTLER A separator, a tub, pan, vat, or tank in which the partial separation of a mixture is made due to difference in density. The operation may be continuous or batch. The separation may be solids from liquid or gas; liquid from gas. SETTLING POINT Laboratory test determining the temperature at which solidification of a molten wax begins. SETTLING TANK A tank employed for separating two liquids which are not miscible. If the liquids do not form an emulsion they separate into layers according to their specific gravities, and these layers can be drawn off from different levels in the tank. SHIFT REACTION

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Conversion of CO to CO2 by addition of water, following general reaction CO + H2O --> CO2 + H2. Both Hi and low temperature shift reactions are used. SHORT RESIDUE The residue resulting from vacuum distillation of long residue. (Removal of vacuum gas oil and waxy distillate). SIDE STRIPPER A fractionating column for stripping undesired volatile components from a side stream which is drawn off as a liquid from a main fractionating column. Various fractions may be drawn off from one main column, and be stripped in as many side strippers. SIDESTREAM A liquid stream taken from any one of the intermediate trays of a trayed distillation column. SIGHT GLASS Device used to directly show the level in a vessel, boiler, etc. by means of a glass tube. SILVER STRIP A very strict corrosion test for AVTUR. SLIDE VALVE A type of valve for controlling or shutting off the flow of catalyst in a continuous regeneration unit. SLOPS A term loosely used to denote: 1. Crude oil containing excessive water contamination which must be removed by settling before pumping to the crude distiller. 2. All products which are off-specification and must be reprocessed before marketing. Such products are for example produced during the start-up period. 81. Created by Ranjit Kumar

SMOKE POINT The maximum height of flame measured in millimetres at which a kerosene will burn without smoking when tested in a standard lamp for this purpose. SOLAR ENERGY Energy produced by radiation from the sun. SOLUBLE OIL Oil which readily forms stable emulsions or colloidal suspensions in water. Used as a cutting fluid in machine work. SOLUTION A homogenous mixture of two or more chemically un-reacted fluids. SOLVENT A substance, usually liquid, capable of dissolving another liquid, gas or solid to form a homogenous mixture. SOLVENT EXTRACTION See Extraction. SOLVENT/FEED RATIO On the BDU, the rate of the total amount of butane (predilution and normal) to short residue. SOOTBLOWER A device for removal of soot from furnace tubes - to increase heat transfer - - generally using a steam blast nozzle. However, a shot drop system (as on the HCU) does the same job and is sometimes referred to as a sootblower. SOUR CRUDE Crude oils containing an abnormally large amount of sulphur and sulphur compounds which break down upon refining to liberate 82. Created by Ranjit Kumar

troublesome quantities of corrosive sulphur compounds. This is a relative term. SOUR GAS Gas which contains objectionable amounts of contaminants, e.g. hydrogen sulphide and other corrosive sulphur compounds. SOUR GASOLINE Gasoline fractions which contain a certain amount of mercaptans and therefore must be sweetened. SOUR WATER Water which contains objectionable amounts of dissolved contaminants, e.g. hydrogen sulphide, ammonia, phenols etc. SPACE VELOCITY A convenient unit for expressing the relationship between feed rate and reactor volume in a flow process. It is defined as the volume or weight of feed (measured at standard conditions) per unit time per unit volume of reactor or per unit weight of catalyst. SPADE A solid plate inserted in a flanged joint to positively isolate one side of the flange from the other. Also called blank, banjo. SPALLING Flaking of the surfaces of metals or refractories, leaving new surfaces exposed.

SPECIFIC GRAVITY The ratio of the weight of a volume of a body to the weight of an equal volume of some standard substance. In the case of liquids and solids, the standard is water, in the case of gases, the standard is hydrogen or air. SPECIFIC HEAT 83. Created by Ranjit Kumar

The ratio of the quantity of heat required to raise the temperature of a body by one degree to that required to raise the temperature of an equal mass of water by one degree. SPECTACLE Or Spec blind. A figure of 8 shaped plate that can be either put to the open or closed position, but always stays in the line. SPLITTER A fractionating tower with overhead and bottoms product streams only. STABILISATION The process of separating light gases from petroleum or gasoline, thus leaving the liquid stable in the sense that it can be handled or stored with less liability to change in composition. STABILISED GASOLINE Gasoline after subjection to fractionation by which the vapour pressure has been reduced to a specified maximum. STABILITY Resistance of petroleum products to chemical change. Gum stability means the resistance of a gasoline to gum forming while in storage. Oxidation stability means that the product is stable to oxidation, i.e resists the action of oxidation which forms gums, sludges etc. STABILISER A fractionating column designed to make a sharp separation between very volatile components and gasoline ex crude oil, casing head gasoline or pressure distillate, thus controlling the gasoline’s Reid vapour pressure. STANDARD PRESSURE Pressure under which the mercury barometer stands at 760mm, or 30in. (Equivalent to approximately 14.7 psia). 84. Created by Ranjit Kumar

STANDARD REFINERY FUEL (SRF) A hypothetical refinery fuel with a gross calorific value of 10336 Kcal/kg. Allows all refinery fuel components to be converted to an SRF equivalent based on calorific values. STAND-BY A term used to designate emergency auxiliary equipment which is not used during normal operation. STATIC ELECTRICITY The electricity generated by the relative movement of unlike materials such as oil/pipeline, oil/water, plastic granules/vessel; or by the operation of equipment such as driving belts. STEAM/AIR DECOKING In heavy oil furnaces over the period of a process run, the differential pressure across the furnace tubes may increase until it is uneconomical to continue the run. This high pressure drop is caused by carbon built up on the inside of the tubes. We can burn this carbon off by steam/air decoking. STEAM DISTILLATION A distillation in which vaporisation of the volatile constituents is effected at a reduced temperature by introduction of steam directly into the charge. Steam used in this manner is termed open steam. STEAM REFORMING As used in the reformer for manufacture of H2 - follows general formula CH4 + H20 --> 3H2 + CO. STEEL A solid state mixture of iron and 1-4% carbon. Can have different structures e.g. Austenitic - strong, ductile

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Pearlitic - low mechanical strength, eventually occurs in furnace tubes when subjected to flame impingement Martensitic - Very hard - used in valve faces etc. STONEWALL The condition where a centrifugal compressor is delivering its maximum flow. STRAIGHT-RUN A term applied to a product of petroleum made by distillation without conversion. STRAINER Alternative term for filter. Used for removal of fine material. STRAPPING The measurement of the external diameter of a cylindrical tank by stretching a steel tape around each course of the tank's plates and recording the measurement. STREAM DAY Denoting 24 hours of actual operation of a refinery unit; in contrast to a calendar day, i.e. takes into account the units availability factor. STRIPPING Removal of the lightest fractions from a mixture. The process is usually carried out by passing the hot liquid from a flash drum or tower into a stripping vessel or stripping section of a column, through which open steam or inert gas is passed to remove the more volatile components of the cut. A fractionating process, closely related to distillation by which undesired volatile components are separated from a liquid mixture by fractional evaporation. The desired fraction is thus purified from lower boiling components. Stripping is generally effected by the introduction of steam, by the reduction of pressure, by the vapour 86. Created by Ranjit Kumar

generated in a reboiler or a combination of these. In the laboratory nitrogen is often used as a stripping agent. STUFFING BOX A device affording the passage and the length wise and rotary motion of a piston rod, shaft, or some similar moving piece while maintaining a fluid-tight seal about the moving part. SULFOLANE Tetrahydro - Thiophene - Dioxide - A component of sulfinol solution. SULPHATE A salt of sulphuric acid, e.g. sodium sulphate, Na2SO4, or ethylsulphate (C2H5)2SO4. SULPHIDE Any of the compounds resulting from the combination of sulphur ions (S==) with metallic or other positive ions, or organic radicals. SULPHUR At NZRC, the final product from H2S removal. A non-metallic element of lemon-yellow colour, sometimes known as brimstone. Sold in liquid form to fertilizer works. SULPHUR DIOXIDE A colourless gas, SO2, a by product of combustion of sulphurous fuels. SULPHURIC ACID Traditionally known as Oil of Vitrol. A combination of sulphur trioxide with water (SO3+H20=H2SO4). it is a eavy, strongly oily liquid, an important water treating agent. SUPERHEATER

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Apparatus which imparts heats to a liquid above that required for vapourisation. e.g. as used for adding heat to steam above the saturation temperature. SURFACE AREA The sum of the outer and inner surfaces. A porous solid may be said to have two different types of area - one made up of the external, the geometric, or the outer surface of the particle; the other, called the inner, made up of the walls of capillaries, crevices, and cracks in the particle. The sum of these is the total surface area. The ratio of total to outer area is sometimes known as the roughness factor. SURFACE TENSION The force exerted by the particles of a liquid at its surface which maintains a continuous surface. The surface tension is determined by measuring the energy required to increase the surface by the unit of area. That property, due to molecular attractive forces and existing in the surface film of all liquids, which tends to bring the volume contained in the liquid surface film into a form having the least surface area. SURGE 1. An upheaval of fluid in a system frequently causing a carryover of liquid through the vapour lines (see also PUKING). 2. An undesirable condition of unstable flow occurring within centrifugal compressors when the surge parameter drops below a critical value. A very dangerous condition for the compressor, hence the need for surge protection (anti-surge line). SURGE DRUM Vessel used to even out the flow into a unit, as the unit throughput and the feed rate may vary. See also buffer. SUSPENSION A heterogeneous mixture of one or more materials - distinct from a solution. The state of a solid or liquid when its particles are mixed with and buoyed in another liquid but are not dissolved by it. A suspension of a liquid in a liquid is called an emulsion. 88. Created by Ranjit Kumar

SWEET GAS Hydrocarbon gas free from sulphur compounds. SWEETENING The process by which petroleum products are improved in odour and colour by oxiding or removing the sulphur-containing and unsaturated compounds. The conversion of the mercaptans present in sour gasoline into non-smelling disulphides. SYNTHESIS The act or process of making or building up a compound by the union of simpler compounds or of its elements.

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