1、BRITISH STANDARD BS 3156-11.2.3: 1986 ISO 6570-3: 1984 Analysis of fuel gases Part 11: Methods for non-manufactured gases Section 11.2 Determination of potential hydrocarbon liquid content Subsection 11.2.3 Volumetric method ISO title: Natural gas Determination of potential hydrocarbon liquid conten
2、t Part 3: Volumetric method UDC 662.76:543BS3156-11.2.3:1986 This British Standard, having been prepared under the directionof the Environment andPollution Standards Committee, was published underthe authority of the BoardofBSI and comes intoeffecton 31January1986 BSI 10-1999 The following BSI refer
3、ences relate to the work on this standard: Committee reference EPC/46 Draft for comment 82/53231 DC ISBN 0 580 14859 9 Committees responsible for this British Standard The preparation of this British Standard was entrusted by the Environment and Pollution Standards Committee (EPC/-) to Technical Com
4、mittee EPC/46 upon which the following bodies were represented: British Ceramic Research Association British Gas Corporation Cement Makers Federation Chemical Industries Association Department of Energy (Gas Standards) Department of Trade and Industry (Electronics Applications Division) Department o
5、f Trade and Industry (Laboratory of the Government Chemist) Department of Trade and Industry (Warren Spring Laboratory) Electricity Supply Industry in England and Wales GAMBICA (BEAMA Ltd.) Institute of Petroleum Institution of Chemical Engineers Institution of Gas Engineers National Coal Board Soci
6、ety of Chemical Industry Society of Glass Technology Society of Motor Manufacturers and Traders Limited Water-tube Boilermakers Association The following bodies were also represented in the drafting of the standard through subcommittees and panels: British Compressed Gases Association British Labora
7、tory Ware Association Amendments issued since publication Amd. No. Date of issue CommentsBS3156-11.2.3:1986 BSI 10-1999 i Contents Page Committees responsible Inside front cover National foreword ii 1 Scope and field of application 1 2 References 1 3 Principle 1 4 Apparatus 1 5 Sampling 1 6 Procedur
8、e 1 7 Expression of results 2 8 Sources of error 2 9 Test report 2 Annex A Example of results obtained for a sample from a cylinder 6 Annex B Example of results obtained for a sample taken by direct sampling from a pipeline 7 Figure 1 General arrangement of the measuring installation 3 Figure 2 Deta
9、il of separator and associated equipment 4 Figure 3 Details of sight glass 5 Publications referred to Inside back coverBS3156-11.2.3:1986 ii BSI 10-1999 National foreword This Subsection of BS3156has been prepared under the direction of the Environment and Pollution Standards Committee. It is identi
10、cal with ISO6570-3:1984“Natural gas Determination of potential hydrocarbon liquid content Part 3: Volumetric method”, published by the International Organization for Standardization (ISO). ISO6570-3was prepared as a result of discussions in Technical Committee 158, Gas Analysis, in which the UK has
11、participated. BS3156was first published as a single standard in1959under the title “Methods for the sampling and analysis of fuel gases”. A first revision was carried out in1968under the title “Methods for the analysis of fuel gases”, Parts 1, 2 and 3 being published in that year. Parts 4 and5of BS3
12、156were published in 1969. This new series of BS 3156, which begins at Part 10, will incorporate methods prepared by ISO/TC 158. In addition, it is intended to revise Parts1to5and published them in the new series. Terminology and conventions. The text of the International Standard has been approved
13、as suitable for publication as a British Standard without deviation. Some terminology and certain conventions are not identical with those used in British Standards; attention is drawn especially to the following. Wherever the words “part of ISO 6570” appear, referring to this standard, they should
14、be read as “Subsection of BS 3156”. The comma has been used as a decimal marker. In British Standards it is current practice to use a full point on the baseline as the decimal marker. In British Standards it is current practice to use the symbol “L” for litre (and its submultiples) rather than “l”.
15、The Technical Committee has reviewed the provisions of ISO3601-1 which is referred to in Figure 3, and has decided that they are suitable for use in conjunction with this British Standard. Any O-ring that fits the grooves as specified in Figure 3, made of an elastomeric material, would be suitable i
16、n practice. NOTEIn Figure 2, for “Thermostatically controlled bath” read “Thermostatically controlled bath”. A British Standard does not purport to include all the necessary provisions of a contract. Users of British Standards are responsible for their correct application. Compliance with a British
17、Standard does not of itself confer immunity from legal obligations. Cross-references International Standard Corresponding British Standard BS 3156: Analysis of fuel gases Part 11: Methods for non-manufactured gases Section 11.2: Determination of potential hydrocarbon liquid content ISO 6570-1:1983 S
18、ubsection 11.2.1:1986 General introduction (Identical) ISO 6570-2:1984 Subsection 11.2.2:1986 Weighing method (Identical) Summary of pages This document comprises a front cover, an inside front cover, pages i and ii, pages 1 to 8, an inside back cover and a back cover. This standard has been updated
19、 (see copyright date) and may have had amendments incorporated. This will be indicated in the amendment table on the inside front cover.BS3156-11.2.3:1986 BSI 10-1999 1 1 Scope and field of application This part of ISO6570specifies a volumetric method for the determination of the potential hydrocarb
20、on liquid content of natural gas. This method permits simultaneous determination of the amount of water that condenses under the conditions of the test. The principles of, and general requirements for, methods for the determination of potential hydrocarbon liquid content are specified in ISO6570-1.
21、An alternative weighing method for the determination of potential hydrocarbon liquid is specified in ISO 6570-2. 2 References ISO 3601-1, Fluid systems O-rings Part 1: Inside diameters, cross-sections, tolerances and size identification code. ISO 6570-1, Natural gas Determination of potential hydroc
22、arbon liquid content Part 1: Principles and general requirements. ISO 6570-2, Natural gas Determination of potential hydrocarbon liquid content Part 2: Weighing method. 3 Principle See ISO 6570-1. The volumes of hydrocarbon liquid (and water if present) formed from given volumes of gas passed throug
23、h the installation at a specific temperature and pressure are measured directly and the potential hydrocarbon liquid content is derived from a graphical presentation of the results. The volume of any condensed water may be derived in a similar manner. 4 Apparatus WARNING The apparatus shall comply w
24、ith relevant safety regulations. The general arrangement of the measuring installation is shown in Figure 1. The measuring installation shall meet the general requirements set out in ISO 6570-1. The separator specified in 4.2 is intended for use at maximum working pressure of8MPa. The actual equipme
25、nt used shall have been tested to an appropriate higher maximum pressure in accordance with the requirements of national safety regulations and shown to be safe. In addition, the following equipment is required. 4.1 Cooling coil The cooling coil shall consist of copper tubing4m long, of external dia
26、meter6mm and internal diameter4,5mm, preferably packed with2mm phosphor-bronze balls. 4.2 Separator (see Figure 2 and Figure 3) The separator assembly (see Figure 2) shall consist of: An upper small vertical chamber surrounded by a constant temperature bath controlled to 0,25K. The lower end is conn
27、ected to a sight glass, of polymethyl methacrylate, having a central tube of restricted width half way up which a reference point is marked (see detail Figure 3). This in turn is connected to a lower chamber, of appropriate capacity to collect the condensate formed, surrounded by a constant temperat
28、ure bath controlled to a temperature5to10K lower than that of the upper chamber. NOTEThe specified separator and filter designs have been tested at a pressure of12MPa. 4.3 Mercury displacement pump A calibrated mercury displacement pump with a scale graduated in0,01ml divisions, with the possibility
29、 of estimating to0,001ml, shall be used. 4.4 Back pressure regulator The back pressure regulator shall be suitable for the pressures to be used. 4.5 Equipment for checking of proper functioning (see subclause 5.3 of ISO 6570-1). 5 Sampling The general conditions for representative sampling set out i
30、n ISO6570-1shall be complied with. 6 Procedure Connect a nitrogen cylinder to the apparatus using a heated line, and set the thermostat of the bath containing the cooling coil to the desired temperature. Raise the mercury level in the sight glass using the displacement pump, set the back pressure re
31、gulator, and pressurize the system with nitrogen. Check for any leaks using soap-solution and carry out any necessary repairs. NOTEIf a sufficiently large sample is available, it may be used for checking for leaks instead of the nitrogen.BS3156-11.2.3:1986 2 BSI 10-1999 Reduce the mercury level to b
32、elow the sight glass, and close the valve to the mercury pump. Vent to reduce the pressure in the installation and adjust the temperature of the lower chamber to at least5K below that of the cooling coil. Evacuate the system and slowly introduce the sample, allowing the gas to slowly flow through th
33、e apparatus (control the gas flow using the back pressure regulator and the fine control valve). Open the valve to the mercury pump, and raise the mercury level in the sight glass by means of the displacement pump. As gas flows through the installation, adjust in turn the levels of the water-liquid
34、hydrocarbon and liquid hydrocarbon-gas interfaces to the reference level in the sight glass and record the mercury pump and gas-meter readings for each adjustment. Record the temperatures of the bath containing the cooling coil and the gas entering the measuring equipment. Note the flow rates throug
35、h the installation and the thermostatically controlled bath and the dew point temperatures of the gas leaving the separator. The gas leaving the separator should be in equilibrium; this may be checked, for example, by measuring the hydrocarbon dew point. 7 Expression of results Convert the pump read
36、ings to liquid volumes and correct the gas volumes to standard conditions(273,15 K and 101 325 Pa). From a series of readings, plot the volumes of gas against the volumes of liquid. After initial scatter, due to wetting of the walls of the installation, the values should give a straight line, the sl
37、ope of which gives the volume of liquid, condensate or water, condensed under the conditions in the separator. Express the results as the ratio of the volume of liquid per unit volume of gas. The recommended unit is cm 3 /m 3 . An example of results obtained from a sample in a cylinder is given in A
38、nnex A and of the results obtained from a sample taken by direct sampling are given in Annex B. 8 Sources of error In addition to the sources of error specified in ISO6570-1, that of particular concern in the volumetric method is the temperature of the lower liquid container. If this is too high, ga
39、ssing will occur in the condensed liquid. To avoid this it is essential that the temperature difference between the separator bath and the lower container bath specified in clause 4 be maintained. 9 Test report The test report shall include the following information: a) a reference to this part of I
40、SO 6570; b) all the information necessary for the complete identification of the sample; c) the results obtained; d) details of any operation not specified in this part of ISO 6570, or ISO 6570-1, or regarded as optional, together with details of any incidents likely to have affected the results.BS
41、3156-11.2.3:1986 BSI 10-1999 3 Figure 1 General arrangement of the measuring installationBS3156-11.2.3:1986 4 BSI 10-1999 Figure 2 Detail of separator and associated equipmentBS3156-11.2.3:1986 BSI 10-1999 5 NOTEAll surfaces to be finished smooth and free from toolmarks. Figure 3 Details of sight gl
42、assBS3156-11.2.3:1986 6 BSI 10-1999 Annex A Example of results obtained for a sample from a cylinder A.1 Sample details Bottle A 2492, sampled from separator operating at 0,34 MPa and 345 K. Dew point of gas leaving cylinder at 0,34 MPa: hydrocarbon: 345 K water: 344 to 345 K A.2 Results Time of day
43、 Volume of gas passed a I Bath temperature K Dew point K Volume of condensed liquid ml Hydrocarbon Water 10:00 0,55 0,75 1,20 1,60 303,0 303,2 303,1 303,0 303,0 303,2 0,07 0,072 0,215 0,345 0,02 10:26 2,00 2,25 303,0 302,8 303,0 0,515 0,650 0,121 10:32 2,50 2,75 302,9 303,1 302,8 0,768 0,853 0,20 10
44、:39 3,00 3,50 303,0 303,0 303,0 0,925 1,112 0,263 10:50 3,80 303,1 1,240 0,365 a Corrected to standard conditions. From the slope of the graph potential liquid hydrocarbon content 4,05 10 4(V/V) potential water (as liquid) content 1,38 10 4(V/V)BS3156-11.2.3:1986 BSI 10-1999 7 Annex B Example of res
45、ults obtained for a sample taken by direct sampling from a pipeline B.1 Sample details Line pressure: 6,9 MPa. Gas with a hydrocarbon dew point of 278 K, cooled to a dew point of273,5to274,0K. B.2 Results Time of day Pressure MPa Bath temperature K Dew point K Volume of liquid ml Gas-meter reading I
46、 Volume of gas passed I 11:04 6,90 6,90 6,90 260,0 260,0 260,5 273,5 274,0 0,181 0,205 0,283 3 960 4 047 4 163 87 203 11:25 6,90 6,90 260,0 260,3 274,0 273,5 0,334 0,433 4 250 4 423 290 463 11:47 6,90 6,90 260,0 260,3 274,0 0,507 0,544 4 540 4 625 580 665 12:00 6,90 274,0 0,589 4 680 720 From the sl
47、ope of the graph, potential liquid hydrocarbon content: 5,9 10 7 (V/V)8 blankBS3156-11.2.3:1986 BSI 10-1999 Publications referred to See national foreword.BS 3156-11.2.3: 1986 ISO 6570-3: 1984 BSI 389 Chiswick High Road London W4 4AL BSIBritishStandardsInstitution BSI is the independent national bod
48、y responsible for preparing BritishStandards. It presents the UK view on standards in Europe and at the international level. It is incorporated by Royal Charter. Revisions BritishStandards are updated by amendment or revision. Users of BritishStandards should make sure that they possess the latest a
49、mendments or editions. It is the constant aim of BSI to improve the quality of our products and services. We would be grateful if anyone finding an inaccuracy or ambiguity while using this BritishStandard would inform the Secretary of the technical committee responsible, the identity of which can be found on the inside front cover. Tel:02089969000. Fax:02089967400. BSI offers members an individual updating service called PLUS which ensures that subscribers automatically receive the latest editions of standards. B
