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1、- = Lb24669 0557914 120 BRITISH STANDARD Methods of test for Petroleum and its products Part 427. Liquefied petroleum gases = Determination of oily residues = High temperature method (Identical with IP 427/97) The European Standard EN IS0 13757 : 1996 has the status of a British Standard NO COPYING
2、WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAW BS EN rso 13757 : 1996 BS 2000 : Fart 427 : 1996 SO 13757 :1996 -,-,- E 3624667 0557935 Ob7 E BS 2000 : Part 427 : 1996 National foreword This British Standard was published under the authority of the Materials and Chemicals Sector Board an
3、d comes into effect on 5 August 1996. It is the English language version of EN IS0 13757 : 19% Liquefied petroleum gases - Determination of oily residues - High temperature method, published by the European Committee for Standardization (CEN), which endorses IS0 13757 : 1996, published by the Intern
4、ational Organization for Standardization (ISO). BS 2000 comprises a series of test methods for petroleum and its products that are published by the Institute of Petroleum (IP) and have been accorded the status of a British Standard. Each method should be read in conjunction with the preliminary page
5、s of IP Standard methods for analysis and testing of petroleum and related products which gives details of the BSI/IP agreement for publication of the series, provides general information on safety precautions, sampling and other matters, and lists the methods published as Parts of BS 2000. The numb
6、ering of the Parts of BS 2000 follows that of the corresponding methods published in IP Standard methods for analysis and testing of petroleum and related products. Under the terms of the agreement between BSI and the Institute of Petroleum, BS 2000 : Part 427/BS EN IS0 13757 will be published by th
7、e IP (in Standard methods for analysis and testing of petroleum and related products and as a separate publication). BS 2000 : Part 427 : 1996 is thus identical with IP 427/97. Compliance with a British Standard does not of itself confer immunity from legal obligations. e Institute of Petroleum or a
8、 steam bath fitted with an orifice of diameter between 58 mm and 62 mm. 6.1 Sample cylinder, stainless steel, fitted with two stainless steel valves, the upper one fitted with a dip tube, maximum service pressure 3 MPa, minimum capacity 3,75 dm3, containing the LPG whose oily residues are to be dete
9、rmined. 6.2 In-line filter support, stainless steel, for high pressure (see annex A, reference Cl). 6.3 Filter discs, plain white membrane, diameter 47 mm, made of a blend of cellulose esters, nominal pore dimension 0.8 pm (see annex A, reference 23. 6.11 Rotary evaporator, any model enabling the ev
10、aporation of at least 200 cm3 of solvent, over a bath of softened water regulated at 65 “C 5 5 “C, from a - ground-necked evaporation flask. NOTE 3 A doublecoil water condenser may suffice for apparatus located in a fume cupboard; otherwise, a solid carbon dioxide/acetone coolant is necessary (see a
11、nnex C rbfertnce 53. 6.4 Cooling coil, stainless steel, made by coiling 5 m of tube of external diameter 3 mm and internal diameter 2 mm onto a mandrel O f diameter approxi- motely 50 mm and fitted with the necessary con- nections (see annex A, reference 33. 2 -,-,- = 3624669 055792 424 6.12 Evapora
12、tion flask, 200-cm3 glass round- bottom flask with a ground neck and fitted with a glass stopper, tare less than 130 g (including stopper). 6.13 Oven, capable of maintaining a temperature of 105 “C * 5 “C. 6.14 Balances 6.14.1 For the sample cylinder, balance with a range of 10 kg minimum, accurate
13、to within f 1 g or better. 6.14.2 For the evaporation flask, balance with a range of 160 g minimum, accurate to within f 0,l mg or better. 6.15 Laboratory gloves, of fine PVC, resistant to dichloromethane and talc-free. 6.16 Desiccator, without desiccating agent. 7 Preparation of equipment 7.1 New g
14、lassware Clean new glassware by immersing it in detergent (5.5) for a minimum of 12 h before use. In case of dispute or when abnormal results have been ob- tained, immerse the glassware in a solution of am- monium peroxodisulfate/sulfuric acid (5.2) for 12 h. After cleaning with detergent or ammoniu
15、m peroxodisulfate/sulf uric acid solution, remove the glassware and rinse it in tap water and then in grade 3 water (5.61, using gloves (6.15) or tongs. Continue to wear gloves when handling the glassware throughout the remainder of the test procedure. Dry the glassware in the oven (6.13) for 30 min
16、. Leave to cool in a desiccator (6.16) for at least 2 h before use (take care that the stopper does not become stuck during cooling). After cleaning the apparatus, carry out the tare by weighing the evaporation flask (with stopper) to the nearest 0 . 1 mg after having unstoppered it for 30 s. 7.2 Pr
17、eviously used glassware Remove any traces of organic products from used glassware by washing it carefully with dichloro- methane (5.4) using gloves. Rinse with acetone (5.1) and dry in the oven (6.13) for 30 min. Continue to wear gloves when handling the glassware throughout the remainder of the tes
18、t procedure. Carefully remove the solvent vapours from the evaporation flask, either - IS0 137 57 :1996(E) by inverting the flask for approximately 10 s or by blowing nitrogen into it. Place the flask, fitted with its stopper, and the rest of the glassware in a desiccator (6.16) for at least 2 h bef
19、ore use (take care that the stopper does not become stuck during cooling). If the glassware is not clean enough, or in case of dispute or when abnormal results have been ob- tained, clean the glassware as described in 7.1, using gloves, having first removed any organic products by rinsing with dichl
20、oromethane (5.4) followed by acetone (5.1 1. After cleaning the apparatus, carry out the tare by weighing the evaporation flask (with stopper) to the nearest 0,l mg after having unstoppered it for 30 s. 7.3 Sampling line The sampling line shall be rinsed first with dichloro- methane (5.41, and then
21、with the LPG to be tested. 8 Test procedure CAUTION - It is essential to work under an explosion-proof hood or in the open, taking all the necessary safety measures, in particular the need to earth equipment to eliminate the risks associ- ated with static electricity. 8.1 Sampling procedure Slowly s
22、hake the sample cylinder containing the LPG to be analysed in order to mix the contents, and then remove a mass of 800 g to 1 2009 of product, weighed to within f 1 g, into a 5-dm shallow-form beaker in accordance with the procedure defined in 8.1 .I and 8.1.2. 8.1.1 Assemble the apparatus, as shown
23、 in figure 1, by connecting the lower valve of the sample cylinder to the sampling line comprising: - the V-needle valve (3); - the in-line filter (4); - the cooling coil (6) immersed in the bath (5). the temperature of which (below - 60 “Cl has been checked with a thermometer; - the spindle-needle
24、valve (7); - a nozzle in the form of a flexible polytetra- fluoroethylene (PTFE) tube (8) or, if not available, a stainless steel tube, enabling flow into the beaker (9). 3 -,-,- E Lb24669 0557923 3b0 E IS0 13757:1996(E) I X 3 2 +F Key 1 Sample cylinder, as defined in 6.1 2 Balance accurate to 1 g (
25、see 6.14.1) 3 V-needle valve admitting LPG into the circuit (see 6.8.2) 4 In-line filter support (see 6.2 and 6.3) 5 Dewar flask filled as stipulated in 6.5 6 Stainless steel cooling coil (see 6.4) 7 Spindle-needle valve (see 6.8.1 1 8 PTFE tube,. length 20 cm 9 Shallow-form 5-dm3 beaker (6.9) conta
26、ining 50 cm3 of dichloromethane (5.4) Figure 1 - Sampling assembly 8.1.2 Having connected the sampling line valves (3) and (7) closed to the sample cylinder, open the lower valve of the cylinder and: - position the beaker (9) containing 50 cm dichloro- methane (5.4) such that the PTFE tube is im- me
27、rsed in the dichloromethane; - purge and fill the line with the LPG to be analysed by opening valve (7) and then, progressively, valve (3). so as not to damage filter (4); - close valves (7) and (3) in turn and then the lower valve of the sample cylinder; - disconnect the sampling line from the samp
28、le cyl- inder and weigh the latter to obtain its mass T in grams; - open the lower valve of the sample cylinder and regulate needle valves (7) and (3) to obtain a steady flow of LPG sample into the beaker, until a mass of about 1 O00 g f 200 g is obtained; - close valves (7) and (3) and the lower va
29、lve of the sample cylinder; - disconnect the sampling line from the sample cyl- inder and weigh the sample cylinder once more to obtain the postsampling cylinder mass P, in grams. - reconnect the purged and filled sampling line to the sample cylinder; -,-,- U 1624669 0557722 2T7 m 0 IS0 IS0 13757:19
30、96(E) 8.1.3 The test sample mass, m, in grams, is deter- mined by subtraction: m , = T - P NOTE 4 When the balance available is close to where test manipulations are performed, the cylinder and sampling line may be weighed together after the latter has been filled and again after the sample has been
31、 taken. 8.2 Evaporation of the LPG Either immerse the beaker to a depth of 10 mm in a water bath (6.1 O) at 15 “C f 5 “C (the temperature of which is regulated by water circulation) or place the beaker on a steam bath (6.1 O). Leave to evaporate until the volume of liquid remain- ing in the beaker i
32、s close to the volume of the di- chloromethane (5.4) introduced at the start (50 cm3). 8.3 Evaporation of the dichloromethane Rinse the walls of the beaker very carefully with ap- proximately 25 cm3 dichloromethane (5.4) and trans- fer the contents into a cleaned and previously prepared (7.2) eva or
33、ation flask (6.12). Rerinse the beaker with 25 cm dichloromethane (5.4) and trans- fer this into the flask. Connect the flask to the rotary evaporator and partially immerse it in a bath of orate the contents until only a few cubic centimetres remain in the flask. Remove the flask from the rotary eva
34、porator. Again carefully rinse the beaker with 50 cm3 dichloromethane (5.4) and transfer this vol- ume to the evaporation flask. Repeat this operation with another 50 cm3 dichloromethane (5.4) and collect this volume in the evaporation flask as well. Replace the flask on the rotary evaporator and ev
35、aporate the contents until only the oily residue remains. IMPORTANT - Do not put the evaporator under vacuum during these evaporations. - - - I : E - = - - I i * * softened water regulated to 65 O C i 5 C and evap m 8.4 Oven drying and weighing Remove the flask from the rotary evaporator. Rinse the
36、outer walls with acetone (5.1 1. Place the flask with the neck horizontal in an oven (6.131 for 1 h. (Check the temperature of the oven with a thermometer.) Because dichloromethane vapours are heavier than air, ensure they are carefully eliminated from the evaporation flask by inverting the flask fo
37、r approxi- mately 10 s or by blowing nitrogen into the flask. Then place the flask fitted with its stopper (take care that the stopper does not become stuck during cool- ing) in a desiccator (6.16) for at least 2 h, and finally weigh the flask (with the stopper) to the nearest 0.1 mg after having un
38、stoppered it for 30 s. The dif- ference between this mass and the tare mass of the flask gives the mass m, of the oily residue obtained during the test. 8.5 Blank test Carry out a blank measurement following the pro- cedure described in 8.3 and 8.4, taking 200 cm3 of the same batch of dichloromethan
39、e (5.4) as used during the test, but this time without the sample, The mass of oily residue obtained during the blank test is %. 9 Calculation Calculate the oily residue of the sample, E, after evaporation, in milligrams per kilogram LPG, using the following equation: (Q-nt() x 1 O00 m1 E = where m,
40、 is the mass of the LPG sample, in grams (see 8.1.3); is the mass of oily residue obtained during the test, in milligrams (see 8.4); 5 is the mass of oily residue obtained during the blank test, in milligrams (see 8.5). 10 Expression o f results Report the result to the nearest 1 mglkg. 11 Precision
41、 The precision of this method, established during interlaboratory tests relating to LPG samples with oily residue contents between 70 mg/kg and 100 mg/kg, using dichloromethane as solvent, and determined on. the basis of statistical examination of interlaboratory test results, is as follows: 11.1 Re
42、peatability, r The difference between two test results obtained by the same operator with the same apparatus under constant operating conditions on nominally identical test material would, in the long run, in the normal and 5 -,-,- - E 3624669 0557923 133 E IS0 13757: 1996(E) 0 IS0 correct operation
43、 of the test method, exceed the value below in only one case in 20. r = 15 mg/kg 11.2 Reproducibility, R The difference between two single and independent results obtained by different operators working in dif- ferent laboratories on nominally identical test material would, in the long run, in the n
44、ormal and correct o p eration of the test method, exceed the value below in only one case in 20. R = 50 mg/kg 12 Test report The test report shall contain at least the following in- formation: a) a reference to this International Standard; b) the type and complete identification of the prod- uct tes
45、ted; c) the solvent used; d) the result of the test, in milligrams oily residue per kilogram LPG sample (see clause 10); e) any deviation, by agreement or otherwise, from the procedure specified; f) the date of the test. 6 -,-,- 3624669 0557924 0 T IS0 13757:1996(E) Annex A (informative) Commerciall
46、y available equipment suitable for the test procedure The tradenames given hereafter are examples of 4 Stainless V-needle valve, valve type mation is given for the convenience of users of this International Standard and does not constitute an OH 441 10, USA endorsement by IS0 of these products. suit
47、able products available commercially. This infor- ss-ovs 2 Whitey Co., 15635 Saranac Road, Cleveland, Filter support, No. XX 45 047 O0 Millipore Corp., Ashby Road, Bedford, MA 01730, USA Filter membranes, No. AAWP 047 O0 Millipore Corp., Ashby Road, Bedford, MA 01730, USA Stainless steel (type 304)
48、tube, ref. 30203 Altech Europe, Begoniastraat 6, B-9731, Nazareth (Eke), Belgium Stainless spindle-needle valve, valve type ss-ss 2 Whitey Co., 15635 Saranac Road, Cleveland, OH 441 10, USA 5 Rotary evaporator Buchi model EL 130 6 Laboratory detergents - Extram Flssig E. Merck, 6100 Darmstadt 1, PO Box 41 19, Germany ICI Ltd., Imperial Chemical House, Millbank, London SW1, England - Decon 90 Prolabo 12, rue Pele, 7501 1 Paris, France - Decontamin -,-,- BS 2000 Series IP THE INSTITUTE OF PETROLEUM = Lb2qbb9 0553925 TOb = The Institute of Pe