1、Designation: D 3902 90 (Reapproved 2004)e1Standard Test Method forRubber Hose for Gas Diffusion of Liquefied Petroleum Gas1This standard is issued under the fixed designation D 3902; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision,
2、the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.e1NOTEWarning notes were editorially moved into the standard text in July 2004.1. Scope1.1 This test method covers th
3、e determination of the volumeof liquefied petroleum gas diffusing through the wall of a hoseduring a specified period of time.1.2 The values stated in SI units are to be regarded asstandard.1.3 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It i
4、s theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.A specific precau-tionary statement is given in the note in Section 5.2. Significance and Use2.1 Rubber hose has an inherent
5、characteristic of permittingdiffusion of a gas through the hose structure. This test methodquantitatively measures the loss of liquefied petroleum gas.3. Apparatus3.1 Water Bath, long enough to accommodate the gas-collecting apparatus and hose.3.2 Gas Supply, provided with a suitable pressure gage a
6、ndemergency excess flow shutoff valve in case of hose failure.3.3 Set of Gas-Collecting Apparatus, consisting of a glasstube at least 10 % longer than the hose being tested and with aninside diameter at least 10 % larger than the outside diameter ofthe hose being tested, a conical funnel 25 mm in di
7、ameter, anda 500-cm3measuring cylinder graduated at 5.0-cm3intervals.3.4 Barometer, to record the barometric pressure during thetest.3.5 Thermometers, two, to record water and air temperatureat the gas-collection point. (For a schematic diagram of the testarrangement, see Fig. 1.)3.6 LP-Gas,2having
8、a minimum purity of 99 mol % pro-pane, and a sulfur content less than 0.005 mass %.4. Test Hose4.1 The test hose shall have a 0.50-m (19.7-in.) free lengthbetween couplings and shall be coupled with suitable cou-plings, that is, band-it-type couplings. If the test hose is rubbercovered, then the cov
9、er should be thoroughly perforated with apricker roll.5. Test Pressure5.1 Unless otherwise specified, conduct the test with theLP-gas in the liquid phase at a pressure of 1000 6 20 kPa (1456 3 psi). Regulate this pressure by keeping the LP-gas tank inthe water bath and adjusting the temperature of t
10、he water toobtain the desired pressure, approximately 28C. (WarningTake special precautions to ensure that the water bath tempera-ture cannot rise accidently, as this will increase the gas pressuresignificantly, creating a danger of explosion. Do the testing ina well-ventilated area. The system shal
11、l be equipped with asafety relief valve set at a gage pressure of 1200 6 35 kPa (1756 5 psi).)6. Procedure6.1 Cap or plug the hose coupling on one end of the testhose and connect the hose coupling on the other end to theLP-gas supply. (Invert the tank when testing in the liquid phaseor use a tank eq
12、uipped with full-length dip tube.)6.2 Flush the inside surface of the test hose with LP-gas toremove air and seal the end.6.3 Locate the test hose in the center of the glass tube andmount in the water bath at an incline angle of approximately20.6.4 Adjust the water bath to the specified temperature.
13、Apply the specified gas pressure to the test hose and maintainthis pressure and the water bath temperature for 14 days. At theend of the 14-day conditioning period, inspect the test appara-tus for leaks and, in particular, the area around the hosecouplings. Leaks will be evident by the formation of
14、gasbubbles in the water bath. If none are found, insert the funnelinto the measuring cylinder, fill the cylinder with water, andmount the funnel over the end of the glass tube.6.5 Collect the gas for a 6-h period or collect 450 to 500 cm3of gas, whichever occurs first, and record the time and thevol
15、ume of gas collected. Repeat this procedure every 24 h until1This test method is under the jurisdiction of ASTM Committee D11 on Rubberand is the direct responsibility of Subcommittee D11.31 on Rubber Hose andBelting.Current edition approved July 1, 2004. Published July 2004. Originally approvedin 1
16、980. Last previous edition approved in 1998 as D 3902 90 (1998).2CP Grade, available from Matheson Gas Products, has been found satisfactoryfor this purpose.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.two successive gas volumes a
17、re within 5 % of each other. Usethe average of two successive readings for calculation of gasdiffusion.6.6 If it is desired to determine gas diffusion at differentpressures, conduct the test at the lowest pressure first.7. Calculation7.1 Express the gas diffusion of the hose in cubic centime-tres of
18、 gas per second per square metre of inner hose surface incontact with the gas.7.2 Correct all results to the standard temperature of273.15K and pressure of 101.35 kPa in a dry condition.7.3 Measure the inside diameter of the test hose at bothends. Use the average of these measurements in the calcula
19、-tions.7.4 Run at least two test samples on each hose. They may,however, run in parallel at the same time.7.5 Calculate the gas diffusion as follows:Gas diffusion, cm3/m2s5 857.88 3 V (1)3 P 2 Pw!/ID 3 L 3 t 273.15 1 T!where:AccuracyID = inside diameter of the hose, mm; 6 0.5 mmL = length of the hos
20、e, m; 6 0.001 mP = barometric pressure (at time of collec-tion), kPa;6 0.7 kPaT = temperature of collection unit (at time ofcollection), C;6 0.10CV = volume of gas collected, cm3; 6 2.0 cm3t = time of test, s; and 6 30 sFIG. 1 Schematic Diagram of the Test ArrangementTABLE 1 Vapor Pressures of Liqui
21、d Water from 15 to 35C, kPaC 0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.915 1.705 1.716 1.727 1.738 1.749 1.760 1.772 1.783 1.794 1.80616 1.817 1.829 1.841 1.853 1.864 1.876 1.888 1.900 1.912 1.92517 1.937 1.949 1.962 1.974 1.987 1.999 2.012 2.025 2.037 2.05018 2.063 2.076 2.089 2.102 2.116 2.129 2.142 2
22、.156 2.169 2.18319 2.196 2.210 2.224 2.238 2.252 2.266 2.280 2.294 2.309 2.32320 2.338 2.352 2.366 2.381 2.396 2.411 2.426 2.441 2.456 2.47121 2.486 2.501 2.517 2.532 2.548 2.563 2.579 2.595 2.611 2.62722 2.643 2.659 2.675 2.692 2.708 2.725 2.741 2.758 2.775 2.79123 2.808 2.825 2.842 2.860 2.877 2.8
23、94 2.912 2.930 2.947 2.96524 2.983 3.000 3.019 3.037 3.056 3.074 3.092 3.111 3.129 3.14825 3.167 3.186 3.204 3.223 3.243 3.262 3.281 3.301 3.321 3.34026 3.360 3.380 3.400 3.420 3.441 3.461 3.481 3.502 3.523 3.54327 3.564 3.585 3.606 3.628 3.649 3.670 3.692 3.713 3.735 3.75728 3.779 3.801 3.823 3.845
24、 3.868 3.890 3.913 3.936 3.959 3.98229 4.005 4.028 4.051 4.075 4.100 4.122 4.146 4.170 4.194 4.21830 4.242 4.267 4.291 4.316 4.340 4.365 4.390 4.415 4.440 4.46631 4.492 4.517 4.543 4.569 4.595 4.621 4.647 4.674 4.700 4.72732 4.754 4.781 4.808 4.835 4.862 4.890 4.918 4.945 4.973 5.00133 5.029 5.058 5
25、.086 5.115 5.143 5.172 5.201 5.230 5.260 5.28934 5.318 5.348 5.378 5.408 5.438 5.468 5.499 5.529 5.560 5.59135 5.622 5.653 5.684 5.716 5.747 5.779 5.811 5.843 5.876 5.908D 3902 90 (2004)e12Pw= vapor pressure of water at temperatureT (as taken from Table 1), kPa.60.01 kPa8. Report8.1 Report the follo
26、wing information:8.1.1 Full description of the hose tested,8.1.2 Gas used,8.1.3 Test temperature,8.1.4 Test pressure,8.1.5 Gas diffusion (cm3/m2 s) corrected to standard tem-perature and pressure, and8.1.6 Any special observations.9. Precision and Bias9.1 The precision and bias of this test method h
27、ave not yetbeen determined. Available interlaboratory test data is inad-equate. An adequate interlaboratory testing program has notbeen conducted since sufficient numbers of laboratories to dothe work have not been located.ASTM International takes no position respecting the validity of any patent ri
28、ghts asserted in connection with any item mentionedin this standard. Users of this standard are expressly advised that determination of the validity of any such patent rights, and the riskof infringement of such rights, are entirely their own responsibility.This standard is subject to revision at an
29、y time by the responsible technical committee and must be reviewed every five years andif not revised, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for additional standardsand should be addressed to ASTM International Headquarters. Your comments w
30、ill receive careful consideration at a meeting of theresponsible technical committee, which you may attend. If you feel that your comments have not received a fair hearing you shouldmake your views known to the ASTM Committee on Standards, at the address shown below.This standard is copyrighted by A
31、STM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,United States. Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the aboveaddress or at 610-832-9585 (phone), 610-832-9555 (fax), or serviceastm.org (e-mail); or through the ASTM website(www.astm.org).D 3902 90 (2004)e13
