1、Designation: D3902 90 (Reapproved 2012)Standard Test Method forRubber Hose for Gas Diffusion of Liquefied Petroleum Gas1This standard is issued under the fixed designation D3902; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the
2、year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This test method covers the determination of the volumeof liquefied petroleum gas diffusing through the wall o
3、f 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 is theresponsibility of the user of this standard to establish appro-priate safety an
4、d 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 characteristic of permittingdiffusion of a gas through the hose structure. This test
5、 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 andemergency excess flow shutoff valve in case of hose failure.3.3 Set of Gas-Collect
6、ing 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 diameter, anda 500-cm3measuring cylinder graduated at 5.0-cm3intervals.3.4 Barometer,
7、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 a minimum purity of 99 mol % pro-pane, and a sulfur content less than 0.005 mass %.4
8、. 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 cover should be thoroughly perforated with apricker roll.5. Test Pressure5.1 Unless oth
9、erwise 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 the water toobtain the desired pressure, approximately 28C. (WarningTake special prec
10、autions 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 shall be equipped with asafety relief valve set at a gage pressure of 1200 6 35 kPa (175
11、6 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 equipped with full-length dip tube.)6.2 Flush the inside surface of the test hose with
12、 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.Apply the specified gas pressure to the test hose and maintainthis pressure and the
13、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 gasbubbles in the water bath. If none are found, insert the funnelinto the measuring
14、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 thevolume of gas collected. Repeat this procedure every 24 h until1This test method is unde
15、r the jurisdiction of ASTM Committee D11 on Rubberand is the direct responsibility of Subcommittee D11.31 on Rubber Hose andBelting.Current edition approved May 1, 2012. Published July 2012. Originally approvedin 1980. Last previous edition approved in 2004 as D3902 90 (2004)1. DOI:10.1520/D3902-90R
16、12.2CP 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 are within 5 % of each other. Usethe average of two successive
17、 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 gas per second per square metre of inner hose surface incont
18、act 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-tions.7.4 Run at least two test samples on each hose. They m
19、ay,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 hose, m; 6 0.001 mFIG. 1 Schematic Diagram of the Test Arrangeme
20、ntTABLE 1 Vapor Pressures of Liquid 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 2.0
21、76 2.089 2.102 2.116 2.129 2.142 2.156 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
22、 2.808 2.825 2.842 2.860 2.877 2.894 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 3.7
23、35 3.75728 3.779 3.801 3.823 3.845 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
24、 4.945 4.973 5.00133 5.029 5.058 5.086 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 5.908D3902 90 (2012)2P = barometric pressure (at time of collec-tion), kPa;6 0.7 kPaT = temperature o
25、f 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 sPw= vapor pressure of water at temperatureT (as taken from Table 1), kPa.60.01 kPa8. Report8.1 Report the following information:8.1.1 Full description of the hose tested,8.1.2
26、 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 have not yetbeen determined. Available interlaboratory test data
27、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 rights asserted in connection with any item mentionedin this stand
28、ard. 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 any time by the responsible technical committee and must be review
29、ed 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 will receive careful consideration at a meeting of theresponsible
30、 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 ASTM International, 100 Barr Harbor Drive, PO Box C700, West Cons
31、hohocken, 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). Permission rights to photocopy the standard may also be secured from the ASTM website (www.astm.org/COPYRIGHT/).D3902 90 (2012)3
