| |
GLOSSARY OF TERMS
The content of this glossary is provided for informational purposes only
Ablation
Process of removal by erosion, melting, evaporation, or vaporization.
Abrasion
A wearing, grinding or rubbing away by friction, usually (but not always) involving the action of particles against or between surfaces.
Absolute (Dynamic) Viscosity
The ratio of shear stress to shear rate, representing a fluid's internal resistance to flow. the fundamental unit of absolute or dynamic viscosity is the poise.
Accreditation
The act of granting recognition by an official accreditation body as the result of a technical and system audit on the basis of an independent set of requirements, e.g. ISO 17025 for testing laboratories
Accuracy
The characteristic of a measurement that tells how close an observed value is to a true value.
Acid digestion
The process of dissolving a sample in an acid matrix, usually accompanied by heating
Active metal
A metal ready to corrode, or being corroded. Contrast with noble metal.
Additives
An agent added to oils, fuels, and coolants to impart specific beneficial properties to the finished products. Additives create new fluid properties, enhance properties already present and reduce the rate at which undesirable changes take place in a fluid during service.
Alkali
Any substance having basic (as opposed to acidic) properties. A more limited definition restricts the alkali to hydroxides of ammonium, lithium, potassium and sodium
Anhydrous
Free of water, especially water of crystallization
API
American Petroleum Institute
Assessment
A systematic process of collecting and analyzing data to determine the current, historical or projected status of an organization.
ASTM
American Society for Testing Materials
Auto-ignition point
The temperature at which a substance ignites without other sources of energy. Also, associated with the spontaneous ignition and sustained combustion of part or all of the fuel-air mixture in an engine.
Ambient Temperature
The temperature of the surrounding medium such as the atmosphere.
Alternate Innage Gage
The innage obtained by subtracting the measured distance between the surface of the liquid in the tank and the reference point from the official reference height of the tank.
Alternate Ullage Gage
The ullage obtained by subtracting the measured height of the liquid in the tank from the official reference height of the tank.
Automatic Sampler
A device used to extract a representative sample from the liquid flowing in a pipe. The automatic sampler generally consists of a probe, sample extractor, flow meter,
controller, and sample receiver.
All-Levels Sample
A sample obtained by lowering a weighted, stoppered bottle or beaker or bottle to a point 1 foot (0.3 meter) above the free water level and then, with a sharp jerk of the line
opening the sampler and raising it at a rate that it is about 75% full (a maximum of 85% full) as it emerges from the liquid.
Automatic Samples
A sample taken by automatic means. The two basic types of automatic samples are:
Flow-Proportional Samples
A sample taken by an automatic sampler from a pipeline at a rate that is proportional to the liquid flow rate.
Time-Proportional Samples
A sample taken from a pipeline at regular intervals during a batch transfer period.
Barrel (BBL)
A unit of volume equal to 42 U.S. gallons or 9702.0 cubic inches.
Base stock
A primary refined petroleum fraction or a selected synthetic material, into which additives are blended to produce finished lubricants.
Batch
Quantity of product resulting from a single blending or other processing operation.
Bill of Lading
A B/L is the basic document between a shipper and a carrier and a shipper and consignee. It represents the contract of carriage and defines the terms and conditions of carriage. It is the final receipt from the carrier for the goods shown on it and for the condition of the goods. It describes the nature, quantity and weight of the cargo carried. It is also the document of title of the goods shown.
Biodiesel
Automotive diesel fuel produced from renewable vegetable oil via transesterification
Black belt
Full-time team leader responsible for implementing process improvement projects-define, measure, analyze, improve and control (DMAIC) or define, measure, analyze, design and verify (DMADV)-within the business to drive up customer satisfaction levels and business productivity.
Blend(ing)
Composite of two or more components or lubricants for the purpose of obtaining the desired physical and/or chemical properties. In petroleum product manufacture, a blend may consist of two or more basestocks or a basestock combined with chemical additives.
Boiling point
The temperature at which a substance boils, or is converted into vapor by bubbles forming within the liquid; it varies with pressure.
Bottom Sample
Sample taken from the bottom of a tank or container with a special bottom can
Brookfield viscosity
Apparent viscosity in cP (centipoise) determined by Brookfield viscometer, which measures the torque required to rotate a spindle at constant speed in oil of a given temperature.
BS&W (bottom sediment and water)
The material that collects in the bottom of storage tanks, usually composed of oil, water, and foreign matter. Also called bottoms, or bottom settling and water.
BTU
British thermal unit. The amount of heat required to raise the temperature of 1 pound of water 1 degree Fahrenheit.
Bunker survey
Impartial determination of the metric quantity of bunker fuel delivered during bunkering of a vessel. Is best combined with a quality analysis of the fuel according to ISO 8217.
Calibration
The comparison of a measurement instrument or system of unverified accuracy to a measurement instrument or system of known accuracy to detect any variation from the required performance specification.
Capillarity
A property of a solid-liquid system manifested by the tendency of the liquid in contact with the solid to rise above or fall below the level of the surrounding liquid; this phenomenon is seen in a smallbore (capillary) tube
Catalyst
A substance which speeds a chemical action without undergoing a chemical change itself during the process.
Cellulose media
A filter material made from plant fibers. Because cellulose is a natural material, its fibers are rough in texture and vary in size and shape. Compared to synthetic media, these characteristics create a higher restriction to the flow of fluids.
Cetane index
An approximation of cetane number based on API gravity and mid-boiling point of a fuel.
Certification
The act of granting recognition by a certification body as the result of a technical and system audit on the basis of an independent set of requirements, e.g. ISO 9000
Certified IFIA inspector
A cargo inspector trained and examined according to the regulations of IFIA
Chromatography
A method of separation based on selective adsorption. A solution of the substance is allowed to diffuse slowly through a column of adsorbent, moved by a gas or solvent flow. Different substances will pass with different speeds down the column and will eventually be separated into zones whose content may be monitored by various types of detectors. If the method is used for separation, the column core can then be pushed out and the zones of material cut apart, or the zones can be eluted by passing more solvent down the column and collecting it in small fractions
CIF (Costs, Insurance & Freight)
The cargo insurance and delivery of goods to the named port of destination (discharge) at the seller's expense. Buyer is responsible for the import customs clearance and other costs and risks.
Cleanliness inspection
Inspection of a tank or hold to verify cleanliness for holding new stock
Collateral management
A system of controlling and managing the receipt and containment of physical commodities, in order to secure a financial loan
Conformity check
The calculation of the statistical chance that a measured value complies with an upper or lower limit set by the specification
Continuous drip Sample
Sample taken with valve on pipeline during the entire discharge or loading
Control chart
A chart with upper and lower control limits on which values of some statistical measure for a series of samples or subgroups are plotted. The chart frequently shows a central line to help detect a trend of plotted values toward either control limit.
Corrective action
The implementation of solutions resulting in the reduction or elimination of an identified problem.
Correlation
A measure of the relationship between two data sets of variables.
Cost of poor quality (COPQ)
The costs associated with providing poor quality products or services, due to internal failure costs, external failure costs, appraisal costs and prevention costs
Cracking
The process whereby large molecules are broken down by the application of heat and pressure to form smaller molecules.
Critical control point
Stage in a product or service delivery process identified being critical for the quality of the output and submitted to specific control measures
Crude oil assay
A set of numeric values describing a crude oil. These values show a mixture of transport-, process- and product quality and quantity related properties. Crude assays are conducted according to precisely defined analytical methods, procedures and laboratory equipment.
Closed Gauging System
A method of obtaining measurements of the tank contents without opening the tank. This may be accomplished by using automatic tank gauges or by taking measurements through a pressure/vapor lock standpipe. This type of gauging is done extensively on vessels with inert gas systems.
Critical Zone
A term used to define the liquid level in a floating roof type storage tank from the point where floating of the roof begins to the point where the roof is fully floating. Sometimes known as the "inaccurate zone" or "partially floating region." The critical zone is identified on tank calibration tables where appropriate.
Closed System Gauging Unit
Closed gauging system measurement equipment specially designed to be used with a specific type of standpipe/vapor lock. The unit may have a single purpose such as taking temperature, ullages, watercuts or samples, or may be a combined unit capable of performing all necessary measurement functions.
Cut
The oil level on the tape or bob or the water level marking on a tape or bob coated with water indicating paste. "Taking a cut" is taking a measurement of the oil or water level.
Calibration Tables (Gauge Or Tank Tables, Innage/ Ullage Tables)
Tables developed by recognized industry methods that represent volumes in each tank according to the liquid (innage) or empty space (ullage) measured in the tank. The tables are entered with linear measurements (for example, feet, inches, meters, centimeters) to obtain calibrated volumes (for example, barrels, cubic meters or cubic feet).
Cargo Quantity Option Certificate
A certificate signed by vessel and shore representatives acknowledging the amount of cargo intended to load.
Clingage
The residue that adheres to the inside surface of a container, such as a ship's tank or shore tank, after it has been emptied.
Demurrage
A fixed sum per day or per hour, agreed to be paid for the detention of the vessel or barge under charter at the expiration of laytime allowed.
Demulsibility
The ability of a fluid that is insoluble in water to separate from water with which it may be mixed in the form of an emulsion.
Density at given temperature in vacuum
The mass of a (liquid) substance per volume unit measured at a given temperature and corrected for the density of air
Deviation
In numerical data sets, the difference or distance of an individual observation or data value from the center point (often the mean) of the set distribution.
Dielectric Strength
A measure of the ability of an insulating material to withstand electric stress (voltage) without failure. Fluids with high dielectric strength (usually expressed in volts or kilovolts) are good electrical insulators.
DIN
Deutsche Industrie Norm
Distillation
Process of driving gas or vapor from liquids or solids by heating, then condensing the vapor for the purposes of separation, purification, or measurement
Distribution
The amount of potential variation in the outputs of a process, typically expressed by its shape, average or standard deviation
DMAIC
A data driven quality strategy for improving processes and an integral part of a Six Sigma quality initiative. DMAIC is an acronym for define, measure, analyze, improve and control.
Dip
A term used to designate either the depth of liquid in a storage tank or the taking of the measurements of such liquid level
Datum Plate
A level metal plate located directly under the reference gauge point to provide a fixed contact surface from which liquid depth measurement can be made.
Datum Point
The point from which all measurements for the calibration of the tank are related.
Dissolved Water
The water contained within the oil forming a solution at the prevailing temperature.
EN
European Norm
Effluent
Material exiting a system.
Emulsibility
The ability of a non-water-soluble fluid to form an emulsion with water.
Emulsion
Intimate mixture of oil and water, generally of a milky or cloudy appearance. Emulsions may be of two types: oil-in water (where water is the continuous phase) and water-in-oil (where water is the discontinuous phase).
Environmental contaminant
Material entering a system from an operating system's external surroundings, such as dust, air, moisture or chemicals.
Erosion
The progressive removal of a machine surface by cavitation or by particle impingement at high velocities.
Fatigue
A structural failure due to flexing caused by cyclic motions or cyclic differential pressures which do not exceed the tensile strength of the material.
Ferrography
A method of debris analysis that uses a high gradient magnetic field to attract, hold and deposit particles contained in a fluid. The resulting slide traps both magnetic and non-magnetic particles, which are then microscopically examined for characteristics that reveal size, composition, mode of wear, and possible source.
Field report
Inspection report with original inspector notes from the field
Filtration
The physical or mechanical process of separating insoluble particulate matter from a fluid by passing the fluid through a filter medium that traps the insoluble particles.
Fire point
The temperature at which vapor released from a combustible liquid will burn continuously when ignited under specified conditions.
Flash point
The lowest temperature at which vapors arising from the oil will ignite momentarily when exposed to a flame.
Fluid
A general classification of physical state, including liquids and gases.
Flushing
A fluid circulation process designed to remove contamination from the wetted surfaces of a fluid system.
First foot
Fill of a cargo tank with liquid cargo till a level of about one foot.
Fitness for use
A term used to indicate that a product or service fits the customer's defined purpose for that product or service.
Foam
An agglomeration of gas bubbles separated from each other by a thin liquid film, which is observed as a persistent phenomenon on the surface of a liquid.
FOB (Free on Board)
The delivery of goods on board a vessel at a named port of origin, at seller's expense. Buyer is amongst others responsible for the risks related to the quality and quantity of the goods, the carriage and insurance costs and other expenses
Friction
The resisting force encountered at the common boundary between two bodies when, under the action of an external force, one body, moves or tends to move relative to the surface of the other.
Fuel blending model
Non-linear and linear mathematical relation(s) used to calculate the properties of fuel blends, based on the properties of the individual fuel components
Full outturn guarantee (FOG)
Guaranteed outturn weight of a consignment where differences between load- and discharge port weights are the responsibility and the risk of the FOG service provider. FOG is arranged under specific contract terms and conditions
Free Water (FW)
The water present in a container that is not in suspension in the contained liquid (oil).
Gauge
An instrument or device for measuring, indicating or comparing a physical characteristic
Gear
A cylindrical or conical part using a tooth or screw-based surface configuration to mechanically transmit power from one portion of a machine to another. Gear designs are based in part on the shaft alignment: parallel, angled, over-and-under, etc
GOST
Set of technical standards maintained by the Euro-Asian Council for Standardization, Metrology and Certification (EACS), a regional standards organization operating under the auspices of the Commonwealth of Independent States (CIS).
Graphite
A crystalline form of carbon having a laminar structure, which is used as a lubricant. It may be of natural or synthetic origin.
Grease
A lubricant composed of an oil or oils thickened with a soap, soaps or other thickener to a semisolid or solid consistency.
Gaging
A process of measuring height of a liquid in a storage tank usually using a weighted graduated steel tape and bob.
Gauge Hatch
The opening in the top of a tank through which gauging and sampling operations are carried out.
Gross Observed Volume (GOV)
The volume or oil including dissolved water, suspended water and suspended sediment but excluding free water and bottom sediment, measured at the oil temperature and pressure prevailing. This may be either the volume in a tank or the difference between the volumes before and after a transfer.
Gross Standard Volume (GSV)
The volume or oil including dissolved water, suspended water and suspended sediment but excluding free water and bottom sediment, calculated at standard conditions, e.g. 15 C
Gross Volume
The indicated volume multiplied by the appropriate meter factor nor the liquid and flow rate concerned, without correction for temperature and pressure.
Note: This includes all water and sediment transferred through the meter.
Gross Standard Volume
The gross volume corrected to the standard conditions. e.g. 15°C and 1.01325 bar.
Note: For refined products, dissolved water, suspended water and sediment are not usually deductible, as limits are commonly prescribed in the quality specification. For this reason the term NET is not used for products.
Hardness
The resistance of a substance to surface abrasion.
Hydraulics
Engineering science pertaining to liquid pressure and flow.
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.
Hydrometer
An instrument for determining either the specific gravity of a liquid or the API gravity.
IFIA
International Federation of Inspection Agencies
Immiscible
Incapable of being mixed without separation of phases. Water and petroleum oil are immiscible under most conditions, although they can be made miscible with the addition of an emulsifier.
Infrared spectra
A graph of infrared energy absorbed at various frequencies in the additive region of the infrared spectrum. The current sample, the reference oil and the previous samples are usually compared
Inhibitor
Any substance that slows or prevents such chemical reactions as corrosion or oxidation.
In-line sampler
A sampling device mounted in (a shunt of) a transport or process pipeline, by which flow through samples are directly taken, possibly in a flow proportional way
Insolubles
Residues of carbon or agglomerates of carbon and other material such as spent additives or oxidation by-products.
Interfacial tension (IFT)
The energy per unit area present at the boundary of two immiscible liquids, usually expressed in dynes/cm.
Inspection
Measuring, examining, testing and gauging one or more characteristics of a product or service and comparing the results with specified requirements to determine whether conformity is achieved for each characteristic.
ISO
International Standard Organization
Interpretation of test results
When several laboratories test an identical sample, they never find exactly the same test results. The measure of the variations in the results is called the reproducibility R (of the test method). R is 2.85 times the standard deviation of the series of test results. This uncertainty in a test result must be considered when you check compliance with a product specification limit
Innage Gage (Dip, Sounding)
The height of the liquid surface from the bottom of the tank (or datum plate).
In-transit loss / Gain
The difference between the Total Calculated Volume on board a vessel after loading and the Total Calculated Volume on board before discharge.
Key performance indicator
A statistical measure of how well an organization is doing. A KPI may measure a company's financial performance or how it is holding up against customer requirements.
Kinematic viscosity
The ratio of the absolute viscosity to the density at the temperature of the viscosity measurement. The metric units of kinematic viscosity are the stoke and centistoke, which correspond to the poise and centipoise of absolute viscosity.
Laboratory
A professional and safely equipped environment for testing materials and handling and storing samples
Letter of protest
Written and signed description of shortcomings and formal protest issued on behalf of the cargo owner against logistic service provider
Line displacement
Displacing the liquid content of a transport line with water or a pigg ball
Liquid
Any substance that flows readily or changes in response to the smallest influence. More generally, any substance in which the force required to produce a deformation depends on the rate of deformation rather than on the magnitude of the deformation.
Lowest detection limit
Lowest amount of material that can still be detected at a signal-to-noise ratio of 2.65
Lubricant
Any usually oily liquid or solid of vegetable, animal, mineral or synthetic origin that reduces friction, heat and wear when applied to the surfaces of moving parts.
Lubricity
Ability of an oil or grease to lubricate; also called film strength
Load on top (LOT)
The procedure of commingling the recovered oil slops with the next cargo by loading the cargo on top of the slops.
Lower Samples
A spot sample obtained at the midpoint of the lower third of the tank contents.
Meter Performance
A general expression used to describe the relationship between the volume registered by a meter and the actual volume that passed through the meter. Meter performance can refer to meter measurement errors, meter factor, meter accuracy, or other criteria.
Middle Samples
A spot sample obtained at the midpoint of the middle of the tank contents.
Management review
A periodic meeting of management at which it reviews the status and effectiveness of the organization's quality management system.
Manifold
An assembly containing multiple inlet and/or outlet ports and integral relating components servicing more than one area.
Middle distillate
One of the distillates obtained between kerosene and lubricating oil fractions in the refining processes. These include light fuel oils and diesel fuel.
MIL-Spec
Military specification; a guide in determining the quality requirements of products used by the military services, published by the United States Department of Defense.
Mineral oil
Any petroleum oil, as opposed to animal or vegetable-based oils.
Miscible
Capable of being mixed in any concentration without separation of phases; e.g., water and ethyl alcohol are miscible.
Multigrade oil
An oil meeting the requirements of more than one SAE viscosity grade classification, and may therefore be suitable for use over a wider temperature range than a single-grade oil.
Napthene
Hydrocarbon characterized by saturated carbon atoms in a ring structure, having the general formula CnH2n; also called cycloparaffin or cycloalkane.
Neutralization number
A measure of the total acidity or basicity of an oil; this includes organic or inorganic acids or bases or a combination thereof
NLGI number
One of a series of numbers classifying the consistency range of lubricating greases, based on the ASTM cone penetration number. The National Lubricating Grease Institute (NLGI) grades are in order of increasing consistency
Non-Newtonian fluid
Fluid, such as a grease or a polymer-containing oil (e.g., multi-grade oil), in which shear stress is not proportional to shear rate.
Nonconformity
The nonfulfillment of a specified requirement (see also "blemish," "defect" and "imperfection").
Normal distribution
The charting of a data set in which most of the data points are concentrated around the average (mean), thus forming a bell shaped curve.
Octane number
Term numerically indicating the relative antiknock value of a gasoline. For octane numbers 100 or below, it is based upon a comparison with the reference fuels isooctane (100 octane number) and n-heptane (0 octane number). The octane number of an unknown fuel is the percent by volume of isooctane with n-heptane which matches the unknown fuel in knocking tendencies under a specified set of conditions.
Oil analysis
Generic term for scientific examination of fluid properties, entrained wear and contamination for a variety of purposes.
Out-of-spec
A term that indicates a unit does not meet a given requirement
Oxidation
The chemical combination of a substance with oxygen. All petroleum products are subject to oxidation, with resultant degradation of their composition and performance. The organic acids formed by oxidation are corrosive to metals. The process is accelerated by heat, light, metal catalysts and the presence of water, acids, or solid contaminants
Oxidation stability
Ability of a substance to resist natural degradation upon contact with oxygen
On board quantity (OBQ)
All the oil, water, sludge and sediment in the cargo tanks and associated lines and pumps on a ship before loading a cargo commences. (This term may not apply to product movements.)
Outturn
The quantity of material discharged from a vessel, measured by a shore terminal.
Outturn Certificate
A statement issued by a receiving terminal and/or cargo surveyor certifying the outturn.
Outturn Loss
The difference in Net Standard Volume of oil between the quantity shown on the Bill of Lading and the quantity shown on the Outturn Certificate. The adjusted loss is the Outturn Loss corrected for the difference between the OBQ and the ROB. where applicable.
Paraffinic
A type of petroleum fluid derived from paraffinic crude oil and containing a high proportion of straight chain saturated hydrocarbons. Often susceptible to cold flow problems
Particle
A minute quantity or solid fragment, not necessarily of uniform composition. Particle size, quantity and characteristics (composition, shape, surface features, color, etc.) are all important factors considered in a total fluid analysis. A particle's visual characteristics may be described generically. They may also have specific terms associated with them, especially when certain wear modes are under examination
Particle count
The number of particles present greater than a particular micron size per unit volume of fluid.
Patch test
A method by which a specified volume of fluid is filtered through a membrane filter of known pore structure. All particulate matter in excess of an "average size," determined by the membrane characteristics, is retained on its surface. Thus, the membrane is discolored by an amount proportional to the particulate level of the fluid sample. Visually comparing the test filter with standard patches of known contamination levels determines acceptability for a given fluid
Penetration
Consistency, expressed as the distance in millimeters that a standard needle or cone penetrates vertically into a sample of the material (for example, grease, bitumen) under known conditions of loading, time, and temperature.
PH
Measure of alkalinity or acidity in water and water-containing fluids. pH
can be used to determine the corrosion-inhibiting characteristic in water-based fluids. Typically, pH > 8.0 is required to inhibit corrosion of iron and ferrous alloys in water-based fluids.
Polymerization
The chemical combination of similar-type molecules to form larger molecules, often in chain-like structures.
Pumpability
The low temperature, low shear stress-shear rate viscosity characteristics of an oil that permit satisfactory flow to and from the engine oil pump and subsequent lubrication of moving components.
Precision
The aspect of measurement that addresses repeatability or consistency when an identical item is measured several times.
Probability
A term referring to the likelihood of occurrence of an event, action or item.
Random sampling
A commonly used sampling technique in which sample units are selected so that all combinations of n units under consideration have an equal chance of being selected as the sample.
Rate of shear
The difference between the velocities along the parallel faces of a fluid element divided by the distance between the faces
Refraction
The change of direction or speed of light as it passes from one medium to another.
Repeatability
The variation in average measurements obtained when two or more chemists in the same laboratory measure the same sample using the same technique. The repeatability is defined in the analytical method.
Reproducibility
The variation in average measurements obtained when two or more laboratories measure the same sample using the same technique. The reproducibility is defined in the analytical method
The reproducibility R is determined by interlaboratory studies on the specific test method. R is a quality characteristic laid down in the test method. Alternative test methods usually have a different reproducibility. Test results can therefore only be interpreted if the test method is mentioned. If the test method is not known results can best be interpreted using the R value of the least reproducible method
Rerefining
A process of reclaiming used lubricant oils and restoring them to a condition similar to that of virgin stocks by filtration, clay adsorption or more elaborate methods.
Running sample
Sample taken from tank where sample container is filled gradually while drawn from bottom to the top.
Rust prevention test
A test for determining the ability of an oil to aid in preventing the rusting of ferrous parts in the presence of water.
Reference Height
The distance from the tank bottom and/or datum plate to the established reference point or mark.
Reference Point (Gage Point)
The point from which the reference height is determined and from which the ullages/innages are taken.
Representative Sample
A small portion extracted from the total volume of material that contains the same proportions of the various flowing constituents as the total volume of liquid being transferred. The precision of extraction must be equal to or better than the method used to analyze the sample.
Sample
In acceptance sampling, one or more units of product (or a quantity of material) drawn from a cargo for purposes of inspection to reach a decision regarding acceptance of the lot.
Saybolt viscosity
Viscosity of a petroleum liquid expressed in Saybolt viscosity seconds, measured by the Furol viscometer or the Universal viscometer
Saturation level
The amount of water that can dissolve in a fluid.
Shear rate
Rate at which adjacent layers of fluid move with respect to each other, usually expressed as reciprocal seconds.
Shear stress
Frictional force overcome in sliding one "layer" of fluid along another, as in any fluid flow. The shear stress of a petroleum oil or other Newtonian fluid at a given temperature varies directly with shear rate (velocity). The ratio between shear stress and shear rate is constant; this ratio is termed viscosity of a Newtonian fluid, the greater the shear stress as a function of rate of shear. In a non-Newtonian fluid -- such as a grease or a polymer-containing oil (e.g. multi-grade oil) -- shear stress is not proportional to the rate of shear. A non-Newtonian fluid may be said to have an apparent viscosity, a viscosity that holds only for the shear rate (and temperature) at which the viscosity is determined.
Ship's composite sample
A representative ship's cargo sample proportionally blended with samples taken from the individual ship cargo tanks
Signal to noise ratio
A mathematical equation that indicates the magnitude of an experimental effect above the effect of experimental error due to chance fluctuations.
Simulated distillation
Boiling range determination of crude oil of petroleum fraction through simulation by gas chromatography
Six Sigma
A methodology that provides businesses with the tools to improve the capability of their business processes. This increase in performance and decrease in process variation lead to defect reduction and improvement in profits, employee morale and quality of product.
Standard deviation
A computed measure of variability indicating the spread of the data set around the mean.
Static friction
The force just sufficient to initiate relative motion between two bodies under load. The value of the static friction at the instant relative motion begins is termed break-away friction
Statistical quality control
The application of statistical techniques to control quality. The term "statistical process control" is often used interchangeably with "statistical quality control," although statistical quality control includes acceptance sampling as well as statistical process control.
Statistical process control
Use of control charts and appropriate procedures to track and eliminate unacceptable physical variables in repetitive manufacturing processes.
Spectrometry
Using the analysis of electromagnetic radiation (light) to determine trace elements and their concentrations in a sample. In the atomic spectrometry techniques most commonly used for trace element analysis, the sample is decomposed by intense heat into a cloud of hot gases containing free atoms and ions of the element of interest. In general, there are four types of thermal sources normally used in analytical atomic spectrometry to perform this decomposition process: flames, furnaces, direct electrical discharges, and plasmas. Instruments which separate, isolate and measure light by wavelength in this way are called spectrographs or spectrometers
Surface tension
The contractile surface force of a liquid by which it tends to assume a spherical form and to present the least possible surface. It is expressed in dynes/cm or ergs/cm2
Surfactant
Surface-active agent that reduces interfacial tension of a liquid. A surfactant used in a petroleum oil may increase the oil's affinity for metals and other materials
Sediment- Suspended Sediment
Non-hydrocarbon solids present within the oil but not in solution.
Stop Gauge
The final gauge reading for a transfer to or from a shore tank or vessel
Suspended Water
The water within the oil which is finely dispersed as small droplets.
Slops
Oil, oil/water/sediment, and emulsions contained in slop tanks or designated cargo tanks. The mixture usually results from tank stripping, tank washing, or dirty ballast phase separation.
Tensile strength
The ratio of maximum load to original cross-sectional area. Also called ultimate strength.
Thermal stability
Ability of a fuel or lubricant to resist oxidation under high temperature operating conditions.
Thermography
The use of infrared thermography whereby temperatures of a wide variety of targets can be measured remotely and without contact. This is accomplished by measuring the infrared energy radiating from the surface of the target and converting this measurement to an equivalent surface temperature.
Time sheet
Time report of events during loading or discharge of liquid cargo
Traceability
The ability to trace a reported measurement through an unbroken chain of comparisons to a national or international standard.
Tribology
The science and technology of interacting surfaces in relative motion, including the study of lubrication, friction and wear. Tribological wear is wear that occurs as a result of relative motion at the surface.
Tap Sample
A sample taken from a valve or connection on a tank or pipeline
Total Calculated Volume (TCV)
The gross standard volume plus the free water measured at the temperature and pressure prevailing.
Total Observed Volume (TOV)
The volume or oil including total water and total sediment, measured at the oil temperature and pressure prevailing. This may be either the volume in a tank or the difference between the volumes before .and after a transfer.
Ullage measurement
Measurement of the height of empty tank space above liquid cargo level
Ullage (Outage) Gage
The distance from the liquid surface to the top of the tank (or reference point).
Upper Sample
A spot sample obtained at the midpoint of the upper of the tank contents.
Upper, Middle, Lower Samples
Spot samples taken from the upper third, the middle and lower thirds of the liquid in the tank. The samples so taken may then be composited or analyzed separately.
Validation
The act of confirming a product or service meets the requirements for which it was intended.
Vapor pressure
Pressure of a confined vapor in equilibrium with its liquid at specified temperature thus, a measure of a liquid's volatility.
Varnish
A thin film deposit resulting from the oxidation and polymerization of fuels and lubricants. Similar to but softer than lacquer, and not removable by mechanical wiping.
Verification
The act of determining whether products and services conform to specific requirements.
Viscosity
Measurement of a fluid's resistance to flow. The common metric unit of absolute viscosity is the poise, which is defined as the force in dynes required to move a surface one square centimeter in area past a parallel surface at a speed of one centimeter per second, with the surfaces separated by a fluid film one centimeter thick. In addition to kinematic viscosity, there are other methods for determining viscosity, including Saybolt Universal Viscosity (SUV), Saybolt Furol viscosity, Engier viscosity, and Redwood viscosity. Since viscosity varies in inversely with temperature, its value is meaningless until the temperature at which it is determined is reported.
Viscosity conversion
Converting the viscosity of a liquid fuel measured at one temperature to the value it exposes at a different temperature
Viscosity index (VI)
Empirical unitless number indicating the effect of temperature change on the kinematic viscosity of an oil. The higher the viscosity index, the smaller the relative change in viscosity with temperature
Viscosity, absolute
The ration of the shearing stress to the shear rate of a fluid. It is usually expressed in centipoise.
Viscosity, kinematic
The absolute viscosity divided by the density of the fluid. It is usually expressed in centistokes.
Viscosity, SUS
Saybolt Universal Seconds (SUS), which is the time in seconds for 60 milliliters of oil to flow through a standard orifice at a given temperature. This viscosity system is still in limited use, although it has been generally replaced by the ISO grading system.
Voice of the customer
The expressed requirements and expectations of customers relative to products or services, as documented and disseminated to the members of the providing organization.
Volatility
Expression of evaporation tendency; the degree and rate at which a liquid vaporizes under set parameters of temperature and pressure. The more volatile a petroleum liquid, the lower its boiling point and the greater its flammability. Changes in liquid stability may result in reduced volatility.
Vessel Experience Factor (VEF)
A compilation of the history of the total calculated volume (TCV) vessel measurements, adjusted for on-board quantity (OBQ) or remaining on board (ROB), compared with the TCV shore measurements.
Wall wash sample
Sample taken by wetting the wall of a tank with a wash solvent and collecting the wash liquid for testing
Wear
The attrition or rubbing away of the surface of a material as a result of mechanical action. There is some difference of opinion on types of wear
Wicking
The active absorption of a liquid into a porous material by capillary forces.
Worked penetration
The penetration of a sample of lubricating grease immediately after it has been brought to 77°F and then subjected to 60 stokes in a standard grease worker.
|
|
|
|
| © Copyright 2011, www.geochem.ae All Rights Reserved |
|
|
| 
