1、Designation:D271311 Designation: D2713 12Designation: 395/98Standard Test Method forDryness of Propane (Valve Freeze Method)1This standard is issued under the fixed designation D2713; 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 () indicates an editorial change since the last revision or reapproval.1. Scope*1.1 This test method covers the measurement of the dryness of propane products that do not contain antifreez
3、e agents such as,but not limited to, commercial propane and special duty propane (see Specification D1835).1.2 The values stated in SI units are to be regarded as the standard. The values in parentheses are for information only.1.3 This standard does not purport to address all of the safety concerns
4、, if any, associated with its use. It is the responsibilityof the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatorylimitations prior to use.2. Referenced Documents2.1 ASTM Standards:2D1265 Practice for Sampling Liquefied Petroleu
5、m (LP) Gases, Manual MethodD1835 Specification for Liquefied Petroleum (LP) Gases3. Terminology3.1 Definitions of Terms Specific to This Standard:3.1.1 freeze-off time, nthe time, in s, for a propane water test valve to freeze under the conditions of this test method.3.1.2 propane water test valve,
6、na specific valve designed and manufactured for performing in this test method.3.1.3 valve freeze, adjrelating to the procedure for determining the dryness of propane for this test method.4. Summary of Test Method4.1 Aliquid-phase sample of the product to be tested is flowed through the propane wate
7、r test valve to cool the valve body.Aftercooling, the test valve is partially closed to a small preset flow rate and the time required for the valve to freeze, due to waterdissolved in the sample and thus interrupt the normal flow, is recorded. Higher dissolved water concentrations will result in sh
8、orterfreeze-off times. The average observed time for several successive observations is recorded as the observed valve freeze time.5. Significance and Use5.1 This test is a functional test in which the water concentration in the product is related to product behavior characteristicsin a pressure-red
9、ucing system of special design to arrive at a measure of product acceptability in common use applications.Experience has demonstrated that excessive water content (dissolved water) will cause freeze-up difficulties in pressure reducingsystems.6. Interferences6.1 Antifreeze agents will interfere with
10、 this test method and can indicate that the product is drier than it really is. However,the relative freeze-off times of such materials tested by this procedure can be an indication of the tendency of these products tocause freezing in pressure-reducing regulators.1This test method is under the juri
11、sdiction of ASTM Committee D02 on Petroleum Products and Lubricants and is the direct responsibility of Subcommittee D02.H0 onLiquefied Petroleum Gas.Current edition approved May 1, 2011.April 15, 2012. Published May 2011.2012. Originally approved in 1968. Last previous edition approved in 20072011
12、asD271307.D271311. DOI: 10.1520/D2713-112.2For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at serviceastm.org. For Annual Book of ASTM Standardsvolume information, refer to the standards Document Summary page on the ASTM website.1This document is
13、 not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Becauseit may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropr
14、iate. In all cases only the current versionof the standard as published by ASTM is to be considered the official document.*A Summary of Changes section appears at the end of this standard.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United State
15、s.7. Apparatus7.1 Propane Water Test Valve3A specially constructed and calibrated valve manufactured solely for this test (Note 1). Thevalve has two open positions, a wide open position for flushing, and a small preset flow position for testing.NOTE 1The propane water test valve is a precision instr
16、ument and it should be so treated. It should not be dropped, strained in any way, ordisassembled, except to clean the filter in accordance with the manufacturers instructions. Valves suspected of being defective should be returned to themanufacturer for inspection, reconditioning or recalibration.7.
17、2 Stop Watch or Timer, measuring in seconds.7.3 LP Gas Sample Cylinder, having a minimum capacity of 11 L (3 U.S. gal).7.4 Cloth, dry, clean.7.5 Connection Tubing, clean pipe or metallic tubing for connecting the propane water test valve to the sample point or samplecylinder. Do not use a rubber hos
18、e or plastic-lined hose.8. Hazards8.1 The primary hazards of handing propane are fire, explosion, and freezing “burns” due to the autorefrigeration of LP gas asit expands.9. Sampling9.1 Moisture test measurements on propane samples should be performed by connecting the test valve directly to the bul
19、ksupply if possible, rather than on samples taken from the bulk supply, due to the risk of uncontrollable sampling errors that canaffect the sensitivity of moisture test measurements. Referee tests should be conducted on the bulk supply.9.2 If the test cannot be run by connecting the apparatus direc
20、tly to the bulk propane supply, a sample may be taken into a clean,dry sample cylinder (7.3). In such cases, the sample shall be collected strictly in accordance with directions given in PracticeD1265.10. Procedure10.1 Sample pressure, at the inlet to the test valve, shall not be more than 100 psi (
21、690 kPa) above the vapor pressure of theproduct at the sample temperature. When sample source pressure is above this limit, use a liquid propane pressure regulator to holdthe pressure, at the inlet to the test valve, within this limit.10.2 Connect (see 7.5) the propane water test valve to the liquid
22、 line of the bulk product source or to the liquid phase connectionof the sample cylinder (7.3), so that the body of the valve is horizontal and the outlet opening is aimed vertically upward. The valveshall be positioned so that the internal surfaces of the outlet opening are clearly visible to the o
23、perator.10.3 Open the main valve on the sample source (Note 2) and set the valve on the test apparatus in the purge position. Purgethe sample line and the apparatus for 15 s.10.4 Close the test valve for 2 or 3 s, open it for 2 or 3 s, close it for 2 or 3 s, and continue this intermittent opening an
24、d closinguntil a uniform frost cover has accumulated on the housing around the outlet of the test valve.10.5 Snap the valve to the test position and simultaneously start the stop watch.10.6 Stop the watch at the instant the liquid propane ceases to flow through the valve (Note 2).NOTE 2The instant l
25、iquid propane stops flowing through the valve, frost will form on the internal surfaces of the valve outlet. The watch shall bestopped at this instant. The operator is forewarned of this instant of stoppage by watching the frost line climb and roll over the lip of the valve outlet.10.7 Disregard the
26、 observed time for the initial freeze-off run. Quickly wipe the test valve outlet threads with a clean, dry cloth.10.8 Open the test valve to the purge position for about 15 s to ensure the removal of ice from the preset opening.NOTE 3Failure to purge the apparatus with the valve open to the purge p
27、osition for about 15 s between tests will give erroneous results. Purgingassures that ice formed in the preset opening in the preceding test will be removed.10.9 Repeat the operations as described in the trial run (beginning at 10.4) until three successive freeze-off times agree with eachother to wi
28、thin 65s.NOTE 4For freeze-off times of less than 1 min, this may require as many as seven or eight test runs.10.9.1 If the freeze-off time on threetwo consecutive test runs is 90 s or greater, the test on the product may be discontinuedand the freeze-off time recorded as greater than 90 s.10.9.2 For
29、 freeze-off times shorter than 90 s, record the average time for three consecutive determinations as the freeze-off time,to the nearest whole second.11. Report11.1 If the valve does not freeze off within 60 s, report the result as “pass” in accordance with this test method. If the valve doesfreeze o
30、ff within 60 s, report the result as a “fail” in accordance with this test method.3Supporting data have been filed at ASTM International Headquarters and may be obtained by requesting Research Report RR:D02-1423.D2713 12212. Precision and Bias12.1 In the case of passfail data or results from other q
31、ualitative tests, no generally accepted method for determining precisionor bias is currently available.NOTE 5Data from a series of tests conducted in 1967 indicate the following: At moisture levels of 14 and 26 ppm, all valves can be expected to givefreeze times over 3 min; at a moisture level of 49
32、 ppm it can be expected that none of the valves will give freeze times over 18 s; at a moisture levelof 93 ppm it can be expected that none of the valves will give freeze times over 5 s.NOTE 6The moisture concentrations in Note 5 are believed to be in parts per million (ppm) by mass, mg/kg, based on
33、 the solubility of water inpropane, which precludes the concentrations from being “ppm by volume.”12.2 BiasThe procedure in this test method for measuring dryness of propane has no bias because the value of dryness isdefined only in terms of this test method.13. Keywords13.1 dryness; freeze valve; p
34、ropane; waterSUMMARY OF CHANGESSubcommittee D02.H0 has identified the location of selected changes to this standard since the last issue(D271307)(D271311) that may impact the use of this standard. (Approved April 15, 2012.)(1) In 10.9.1, the number of repeated determinations was reduced from three t
35、o two when the first two determinations are 90seconds.Subcommittee D02.H0 has identified the location of selected changes to this standard since the last issue(D271307) that may impact the use of this standard. (Approved May 1, 2011.)(1) Added a new Note 6 to clarify the units of water concentration
36、 used in Note 5.(2) Revised 10.9-10.9.2 to reduce the maximum test time to 90 s and increase the required repeatability to 65s.ASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard. Users of this standard are
37、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 reviewed every five years andif not re
38、vised, 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 technical committee, which you
39、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 Conshohocken, PA 19428-2959,United S
40、tates. 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/).D2713 123
