ISO/TC 28/SC 2 - Measurement of petroleum and related products

This document specifies methods for the calibration of tanks above eight metres in diameter with cylindrical courses that are vertical. It provides two methods for determining the volumetric quantity of the liquid contained within a tank at gauged liquid levels. NOTE For optical-reference-line method, the optical (offset) measurements required to determine the circumferences can be taken internally or externally, provided that insulation is removed if tank is insulated. The methods are suitable for tilted tanks with up to 3 % deviation from the vertical provided that a correction is applied for the measurement tilt, as described in ISO 7507-1. These methods are alternatives to other methods such as strapping (ISO 7507-1) and the optical-triangulation method (ISO 7507-3).

This document specifies procedures and requirements for the transfer of bunkers to vessels by bunker tankers using the Coriolis mass flow meter (MFM) system. It encompasses the process leading to the approval of the MFM system as installed on bunker tankers and post-approval bunkering operation. It covers terminology, specifications, requirements and procedures on metrology, system integrity, metering system selection and installation, MFM system verification, bunker delivery and dispute handling. NOTE Local and international regulations, such as the International Convention for the Prevention of Pollution from Ships (MARPOL) can apply.

This document establishes a common basis for, and assistance in, the classification of applications and multiphase meters, as well as guidance and recommendations for the implementation and use of such meters. The so-called in-line multiphase flow meters (MPFMs) that directly measure the oil, water and gas flow rates, as well as the partial- and full-separation MPFMs are the main focus of this document. Conventional two- or three-phase separators are not included in this document. Only limited reference is made to wet-gas meters, since although wet-gas flow is a subset of multiphase flow, wet-gas measurement is covered by ISO/TR 11583 and ISO/TR 12748.

This document describes the design, use and calibration of volumetric measures (capacity measures) which are intended for use in fixed locations in a laboratory or in the field. This document gives guidance on both standard and non-standard measures. It also covers portable and mobile measures. This document is applicable to the petroleum industry; however, it may be applied more widely to other applications. This document excludes measures for cryogenic liquids and pressurized measures as used for liquid petroleum gas (LPG) and liquefied natural gas (LNG). Volumetric measures are classified as test measures or prover tanks depending on capacity and design. Measures described in this document are primarily designed, calibrated and used to measure volumes from a measure which is wetted and drained for a specified time before use and designated to deliver. Many of the provisions, however, apply equally to measures which are used to measure a volume using a clean and dry measure and designated to contain. Guidance is given regarding commonly expected uncertainties and calibration specifications. The document also provides, in Annex A, reference formulae describing the properties of water and other fluids and materials used in volumetric measurement more generally.

This document specifies procedures and requirements for the transfer of bunkers to vessels involving bunker tankers, road tankers and shore pipelines. It is applicable to pre-delivery, delivery and post-delivery checks and documentation.

ISO 2714:2017 describes and discusses the characteristics of displacement flowmeters. Attention is given to the factors to be considered in the application of positive displacement meters to liquid metering. These include the properties and nature of the liquid to be metered, the correct installation and operation of the meter, environmental effects, and the wide choice of secondary and ancillary equipment. Aspects of meter proving and maintenance are also discussed. ISO 2714:2017 is applicable to the metering of any appropriate liquid. Guidance is given on the use of positive displacement meters in the metering of two-component mixtures of the same phase such as water and oil. It is not applicable to two-phase flow when gases or solids are present under metering conditions (i.e. two-phase flow). It can be applied to the many and varied liquids encountered in industry for liquid metering only. It is not restricted to hydrocarbons. Guidance on the performance expected for fiscal/custody transfer applications for hydrocarbons is outlined. ISO 2714:2017 is not applicable to cryogenic liquids such as liquefied natural gas (LNG) and refrigerated petroleum gas. It does not cover potable water and fuel dispenser applications.

ISO 2715:2017 describes and discusses the characteristics of turbine flowmeters. Attention is given to the factors to be considered in the application of turbine meters to liquid metering. These include the properties and nature of the liquid to be metered, the correct installation and operation of the meter, environmental effects, and the wide choice of secondary and ancillary equipment. Aspects of meter proving and maintenance are also discussed. ISO 2715:2017 is applicable to the metering of any appropriate liquid. Guidance is given on the use of turbine meters in the metering of two-component liquid mixtures such as water and oil. It is not applicable to two-phase flow when gases or solids are present under metering conditions (i.e. two-phase flow). It can be applied to the many and varied liquids encountered in industry for liquid metering and is not restricted to hydrocarbons. Guidance on the performance expected for fiscal/custody transfer applications for hydrocarbons is outlined. ISO 2715:2017 is not applicable to cryogenic liquids, such as liquefied natural gas (LNG) and refrigerated petroleum gas. It does not cover potable water applications.

ISO 91:2017 refers to temperature volume correction factors, which allow users to convert volumes, measured at ambient conditions, to those at reference conditions for transactional purposes. This document also refers to compressibility factors required to correct hydrocarbon volumes measured under pressure to the corresponding volumes at the equilibrium pressure for the measured temperature.

ISO 12917-1:2017 specifies manual methods for the calibration of nominally horizontal cylindrical tanks, installed at fixed locations. The methods in this document are applicable to insulated and non-insulated tanks, either when they are above-ground or underground. The methods are applicable to pressurized tanks and to both knuckle-dish-end and flat-end cylindrical tanks as well as elliptical and spherical head tanks. ISO 12917-1:2017 is applicable to tanks inclined from the horizontal, provided a correction is applied for the measured tilt. Although this document does not impose any limits on the maximum tank diameter and maximum tank tilt to which this document is applicable, the practical limits would be about 4 m in diameter and 10° in tilt.

ISO 7507-4:2010 specifies a method for the calibration of vertical cylindrical tanks having diameters greater than 5 m by means of internal measurements using an electro-optical distance-ranging (EODR) instrument, and for the subsequent compilation of tank capacity tables. ISO 7507-4:2010 is suitable for tanks tilted up to a 3 % deviation from the vertical, provided that a correction is applied for the measured tilt as described in ISO 7507-1:2003, Clause 11. ISO 7507-4:2010 also applies to tanks with floating roofs or internal floating blankets.

ISO 7507-3:2006 specifies a calibration procedure for application to tanks above 8 m in diameter with cylindrical courses that are substantially vertical. It provides a method for determining the volumetric quantity contained within a tank at gauged liquid levels. The measurements required to determine the radius are made either internally or externally. The external method is applicable only to tanks that are free of insulation. ISO 7507-3:2006 is suitable for tanks tilted up to a 3 % deviation from the vertical, provided that a correction is applied for the measured tilt as described in ISO 7507-1.

ISO 11223:2004 gives guidance on the selection, installation, commissioning, maintenance, validation and calibration of hydrostatic tank-gauging (HTG) systems for the direct measurement of static mass in petroleum storage tanks. It is intended to cover custody transfer applications, although details of other, less accurate, measurements are included for information. It also gives guidance on calculations of standard volume from measured mass and independently measured reference density. Information is also included on measurements of observed and standard volume using density measured by the HTG system itself. ISO 11223:2004 is applicable to hydrostatic tank-gauging systems which use pressure sensors with one port open to the atmosphere. It is applicable to the use of hydrostatic tank gauging on vertical, cylindrical, atmospheric storage tanks with either fixed or floating roofs. ISO 11223:2004 is not applicable to the use of hydrostatic tank gauging on pressurized tanks.

ISO 3838:2004 specifies methods for the determination of the density or relative density of crude petroleum and of petroleum products handled as liquids. The capillary-stoppered pyknometer method is also for use with solids and this method may also be used for coal tar products, including road tars, creosote and tar pitches, or for mixtures of these with petroleum products. This method is not suitable for the determination of the density or relative density of highly volatile liquids having Reid vapour pressures greater than 50 kPa according to ISO 3007 or having an initial boiling point below 40 degrees Celsius. The graduated bicapillary pyknometer method is recommended for the accurate determination of the density or relative density of all except the more viscous products, and is particularly useful when only small amounts of samples are available. The method is restricted to liquids having Reid vapour pressures of 130 kPa or less according to ISO 3007 and having kinematic viscosities less than 50 mm2/s (50 centistokes (cSt)) at the test temperature. Special precautions are specified for the determination of the density or relative density of highly volatile liquids.

ISO 3170:2004 specifies the manual methods to be used for obtaining samples of liquid or semi-liquid hydrocarbons, tank residues and deposits from fixed tanks, railcars, road vehicles, ships and barges, drums and cans, or from liquids being pumped in pipelines. ISO 3170:2004 applies to the sampling of petroleum products, crude oils and intermediate products, which are stored in tanks at or near atmospheric pressure, or transferred by pipelines, and are handled as liquids at temperatures from near ambient up to 200 degrees Celsius. The sampling procedures specified are not intended for the sampling of special petroleum products which are the subject of other International Standards, such as electrical insulating oils (IEC 60475), liquefied petroleum gases (ISO 4257), liquefied natural gases (ISO 8943) and gaseous natural gases (ISO 10715).

ISO 7507-1:2003 specifies a method for the calibration of substantially vertical cylindrical tanks by measuring the tank using a strapping tape. This method is known as the strapping method and is suitable for use as a working method, a reference method or a referee method. The operation of strapping, the corrections to be made and the calculations leading to the compilation of the tank capacity table are described. This method does not apply to abnormally deformed, e.g. dented or non-circular, tanks. This method is suitable for tilted tanks with a deviation of up to 3 % from the vertical, provided that a correction for the measured tilt is applied in the calculations.

ISO 15169:2003 gives guidance on the selection, installation, commissioning, calibration and verification of hybrid tank measurement systems (HTMS) for the measurement of level, static mass, observed and standard volume, and observed and reference density in tanks storing petroleum and petroleum products in fiscal or custody transfer application. As it is a matter for the user to decide which measurements (i.e. volume, or mass or both) are used for custody transfer purposes, this International Standard includes an uncertainty analysis, with examples, to enable users to select the correct components of an HTMS to address the intended application. ISO 15169:2003 is applicable to stationary, vertical cylindrical tanks storing liquid hydrocarbons with a Reid Vapour Pressure (RVP) below 103,42 kPa. ISO 15169:2003 is not applicable to pressurized tanks or marine applications.

ISO 11563:2003 establishes procedures to achieve the fullness of a pipeline system. ISO 11563:2003 is applicable to crude oils and petroleum products which are liquid at atmospheric pressure and at the observed temperature. It can be applied to loading, discharges and movements between local storage tanks. It is not the intention of this standard to recommend practices for transcontinental movements.

ISO 4266-6 gives guidance on the selection, accuracy, installation, commissioning, calibration and verification of automatic tank thermometers (ATTs) in fiscal/custody transfer applications in which the ATT is used for measuring the temperature of petroleum and liquid petroleum products stored in pressurized storage tanks. ISO 4266-6 is not applicable to the measurement of temperature in caverns or in refrigerated storage tanks.

ISO 4266-4 gives guidance on the selection, accuracy, installation, commissioning, calibration and verification of automatic tank thermometers (ATTs) in fiscal/custody transfer applications in which the ATT is used for measuring the temperature of petroleum and liquid petroleum products having a Reid vapour pressure less than 100 kPa, stored in atmospheric storage tanks. ISO 4266-4 is not applicable to the measurement of temperature in caverns or in refrigerated storage tanks.

ISO 4266-5 gives guidance on the selection, accuracy, installation, commissioning, calibration and verification of automatic tank thermometers (ATTs) in fiscal/custody transfer applications in which the ATT is used for measuring the temperature of petroleum and liquid petroleum products having a Reid vapour pressure less than 100 kPa, stored in cargo tanks on board marine vessels. ISO 4266-5 is not applicable to the measurement of temperature in refrigerated storage tanks, or pressurized cargo tanks on board marine vessels.

ISO 4266-1 gives guidance on the accuracy, installation, commissioning, calibration and verification of automatic level gauges (ALGs), of both intrusive and non-intrusive types, for measuring the level of petroleum and petroleum products having a Reid vapour pressure less than 100 kPa, stored in atmospheric storage tanks. This part of ISO 4266 is not applicable to the measurement of level in refrigerated storage tanks with ALG equipment.

ISO 4266-2 gives guidance on the accuracy, installation, calibration and verification of automatic level gauges (ALGs), both intrusive and non-intrusive, for measuring the level of petroleum and liquid petroleum products having a Reid vapour pressure less than 100 kPa, transported aboard marine vessels (i.e. tankers and barges). ISO 4266-2 gives guidance for buyers and sellers who mutually agree to use marine ALGs for either fiscal and/or custody transfer applications. ISO 4266-2 is not applicable to the measurement of level in refrigerated cargo tanks.

ISO 4266-3 gives guidance on the accuracy, installation, commissioning, calibration and verification of automatic level gauges (ALGs) both intrusive and non-intrusive, for measuring the level of petroleum and petroleum products having a vapour pressure less than 4 MPa, stored in pressurized storage tanks. ISO 4266-3 gives guidance on the use of ALGs in custody transfer application. ISO 4266-3 is not applicable to the measurement of level in caverns and refrigerated storage tanks with ALG equipment.

ISO 12917-2:2002 specifies a method for the calibration of horizontal cylindrical tanks having diameters greater than 2 m by means of internal measurements using an electro-optical distance-ranging instrument, and for the subsequent compilation of tank-capacity tables. This method is known as the internal electro-optical distance-ranging (EODR) method. ISO 12917-2:2002 is applicable to tanks inclined by up to 10 % from the horizontal, provided a correction is applied for the measured tilt.

This International Standard specifies a method for the calibration of tanks by addition of batches of liquid. The liquid is used as a volume-transfer medium, measured accurately by means of a meter. This International Standard is not applicable to the calibration of reference measuring instruments, proving tanks, or meter provers. NOTE Applicable standards are given in the bibliography.

This International Standard specifies the requirements for the equipment required to measure manually the liquid level or the corresponding volume of petroleum and petroleum products stored in tanks and containers.

This International Standard specifies a method for the direct determination of water in petroleum products boiling below 390 °C. It covers the mass fraction range 0,003 % (m/m) to 0,100%(m/m). It is not applicable to products containing ketones or to residual fuel oils. This International Standard may be applicable to lubricating base oils. However, the precision has not been established for these materials. The precision given in clause 12 is based upon data obtained using dual-cell, dual-electrolyte systems. NOTE 1 A number of substances and classes of compounds associated with condensation or oxidation-reduction reactions interfere in the determination of water by Karl Fischer titration. In petroleum products, the most common interferences are hydrogen sulfide and mercaptan sulfur, however, mass fractions of these below 0,003 % (m/m) as sulfur will not cause significant interference over the range 0,003 % (m/m) to 0,100%(m/m) water. Other organic sulfur compounds commonly present such as sulfides, disulphides and thiophenes, do not interfere. NOTE 2 An alternative procedure is provided for information in annex B for the direct determination of water over the range 0,003 % (V/V) to 0,100 % (V/V) in petroleum products. The limitations under which this alternative volume measurement may be used are listed in annex B. NOTE 3 For the purposes of this International Standard, the terms "% (m/m)" and "% (V/V)" are used to represent the mass and volume fraction of a material respectively.

This part of ISO 7507 specifies a method for the calibration of non-insulated vertical cylindrical tanks having diameters greater than 5 m, by means of external measurement using an electro-optical distance-ranging method (EODR), and for the subsequent compilation of tank capacity tables. This part of ISO 7507 is applicable to tanks with cone-up or cone-down bottoms as well as to tanks with flat bottoms.

This International Standard specifies a method for determination of water up to 25 % in petroleum products, bitumens, tars and products derived from these materials, excluding emulsions, by the distillation method. The specific products considered during the development of this test method are listed in Table 3. This International Standard may be used to determine water content in excess of 25 %. However, no precision data has been determined at levels greater than 25 %. Volatile water-soluble material, if present, is measured as water. NOTE 1 A knowledge of the water content of petroleum products is important in the refining, purchase, sale and transfer of products. NOTE 2 The amount of water determined by this method can be used to correct the volume involved in the custody transfer of product.

Gives a method for the determination, using an oscillation U-tube densitometer, of the density of crude petroleum and related products within the range 600 kg/m^3 to 1 100 kg/m^3 which can be handled as single-phase liquids at the test temperature and pressure.

In dynamic measuring systems the performance of meters for liquid hydrocarbons will vary with changes in flow conditions, viz. flowrate, viscosity, temperature, pressure, density of product, and with mechanical wear. Has been prepared as a guide for establishing and monitoring the performance of such meters, using appropriate statistical control procedures for both central and on-line proving. These procedures may be applied to measurements made by any type of volumetric or mass metering systems. The procedures to be followed for collecting data, on which the control limits are based, are described.

Defines viscous hydrocarbons and describes the difficulties that arise when they are raised to high temperatures. The effects of such temperatures upon meters, auxiliary equipment and fittings are discussed, and advice and warnings to overcome or mitigate difficulties are included.

The precision data of this procedure have only been determined for water contents up to 1 % (V/V). Includes principle, apparatus, solvent, calibration and recovery test, sampling, procedure, expression of results, precision and test report. The distillation apparatus is shown in figures 1 and 2. The precision of the method is shown in figure 3. The sample handling is described in annex A.

Specifies a method for the laboratory determination. The precision data of this procedure have only been determined for water contents up to 1 % (V/V). Includes principle, apparatus, reagents, sampling, procedure, expression of results, precision and test report. A centrifuge tube is shown in figure 1. The procedure for reading the volume of water and sediment is shown in figure 2. The precision of the method is shown in figure 3. The sample handling is described in annex A.

Recommends procedures for crude oil and liquid petroleum products being conveyed by pipeline. Does not apply to liquefied petroleum gases and liquefied natural gases. The principal purpose ist to give guidelines for specifying, testing, operating, maintaining and monitoring crude oil samples.

Provides guidance for the design, installation and calibration of these provers. Calculation techniques for use when calibrating and operating provers are detailed in ISO 4267-2. Most of the material is general in that it applies to provers for use with different liquids and types of meters and for proving them in different services. Does not apply to the newer "small volume" or "compact" provers.

Defines the various terms employed in the calculation of metered petroleum quantities. Also specifies the equations which allow the values of correction factors to be computed. Also gives rules for the sequence, rounding and significant figures to be employed in a calculation. Provides tables which may be used to look up specific correction factors should it not be desired to calculate them by manual as well as computer methods. The field of application is the volumetric measurement of liquid hydrocarbons, including liquefied petroleum gases, by meter and prover. It does not include two-phase fluids.

The purpose of proving a meter is to determine its relative error or its meter factor as a function of flow rate and other parameters such as temperature, pressure and viscosity. The following types of proving systems are in use: tank prover systems; pipe provers, bidirectional and unidirectional; master meters. They can be used either connected (fixed or mobile) to the metering station or in a central proving station.

The prescribed apparatus shall not be used for materials having gauge vapour pressures higher than 1,4 MPa (absolute vapour pressure 1,5 MPa) at the test temperature. Alternative calibration procedures are described, but only the one using a certified hydrometer is suitable for the determination of density to be used in calculations of qualities for custody transfer or fiscal purposes.

Establishes guidelines for ensuring the quantities stated, a main objective being to ensure the integrity of the primary indication. In order to achieve different levels of security, criteria and recommendations for the design, installation, use and maintenance of the relevant equipment are laid down. Regulatory requirements, including those for safety, are not specifically covered in detail but certain general cautionary notes on safety are included for guidance.

ISO 13739:2010 specifies procedures and requirements for the transfer of bunkers to vessels involving bunker tankers, road tankers and shore pipelines. It applies to pre-delivery, delivery and post-delivery checks and documentation.