1、Designation: D2713 11Designation: 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, the year of last re
2、vision. 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 drynessof propane products that do not contain antifreeze agents suchas, but
3、not limited to, commercial propane and special dutypropane (see Specification D1835).1.2 The values stated in SI units are to be regarded as thestandard. The values in parentheses are for information only.1.3 This standard does not purport to address all of thesafety concerns, if any, associated wit
4、h its use. It is 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.2. Referenced Documents2.1 ASTM Standards:2D1265 Practice for Sampling Liquefied Petroleum (LP)Gases, Manual M
5、ethodD1835 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 watertest valve to freeze under the conditions of this test method.3.1.2 propane water test valve, na specific valve desig
6、nedand manufactured for performing in this test method.3.1.3 valve freeze, adjrelating to the procedure for deter-mining the dryness of propane for this test method.4. Summary of Test Method4.1 A liquid-phase sample of the product to be tested isflowed through the propane water test valve to cool th
7、e valvebody. After cooling, the test valve is partially closed to a smallpreset flow rate and the time required for the valve to freeze,due to water dissolved in the sample and thus interrupt thenormal flow, is recorded. Higher dissolved water concentra-tions will result in shorter freeze-off times.
8、 The averageobserved time for several successive observations is recordedas the observed valve freeze time.5. Significance and Use5.1 This test is a functional test in which the water concen-tration in the product is related to product behavior character-istics in a pressure-reducing system of speci
9、al design to arriveat a measure of product acceptability in common use applica-tions. Experience has demonstrated that excessive water con-tent (dissolved water) will cause freeze-up difficulties inpressure reducing systems.6. Interferences6.1 Antifreeze agents will interfere with this test methodan
10、d can indicate that the product is drier than it really is.However, the relative freeze-off times of such materials testedby this procedure can be an indication of the tendency of theseproducts to cause freezing in pressure-reducing regulators.7. Apparatus7.1 Propane Water Test Valve3Aspecially cons
11、tructed andcalibrated 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 instrument and itshould be so treated. It should not be dropped, s
12、trained in any way, ordisassembled, except to clean the filter in accordance with the manufac-turers instructions. Valves suspected of being defective should bereturned to the manufacturer for inspection, reconditioning or recalibra-tion.7.2 Stop Watch or Timer, measuring in seconds.7.3 LP Gas Sampl
13、e Cylinder, having a minimum capacity of11 L (3 U.S. gal).7.4 Cloth, dry, clean.1This test method is under the jurisdiction of ASTM Committee D02 onPetroleum Products and Lubricants and is the direct responsibility of SubcommitteeD02.H0 on Liquefied Petroleum Gas.Current edition approved May 1, 2011
14、. Published May 2011. Originallyapproved in 1968. Last previous edition approved in 2007 as D271307. DOI:10.1520/D2713-11.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, ref
15、er to the standards Document Summary page onthe ASTM website.3Supporting data have been filed at ASTM International Headquarters and maybe obtained by requesting Research Report RR:D02-1423.1*A Summary of Changes section appears at the end of this standard.Copyright ASTM International, 100 Barr Harb
16、or Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.7.5 Connection Tubing, clean pipe or metallic tubing forconnecting the propane water test valve to the sample point orsample cylinder. Do not use a rubber hose or plastic-lined hose.8. Hazards8.1 The primary hazards of handing pr
17、opane are fire,explosion, and freezing “burns” due to the autorefrigeration ofLP gas as it expands.9. Sampling9.1 Moisture test measurements on propane samples shouldbe performed by connecting the test valve directly to the bulksupply if possible, rather than on samples taken from the bulksupply, du
18、e to the risk of uncontrollable sampling errors thatcan affect 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 apparatusdirectly to the bulk propane supply, a sample may be taken intoa clean, dry sampl
19、e cylinder (7.3). In such cases, the sampleshall be collected strictly in accordance with directions given inPractice D1265.10. Procedure10.1 Sample pressure, at the inlet to the test valve, shall notbe more than 100 psi (690 kPa) above the vapor pressure of theproduct at the sample temperature. Whe
20、n sample sourcepressure is above this limit, use a liquid propane pressureregulator to hold the pressure, at the inlet to the test valve,within this limit.10.2 Connect (see 7.5) the propane water test valve to theliquid line of the bulk product source or to the liquid phaseconnection of the sample c
21、ylinder (7.3), so that the body of thevalve is horizontal and the outlet opening is aimed verticallyupward. The valve shall be positioned so that the internalsurfaces of the outlet opening are clearly visible to the operator.10.3 Open the main valve on the sample source (Note 2) andset the valve on
22、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 andclosing until a uniform frost cover has accumulated on thehousing around the outlet
23、of the test valve.10.5 Snap the valve to the test position and simultaneouslystart the stop watch.10.6 Stop the watch at the instant the liquid propane ceasesto flow through the valve (Note 2).NOTE 2The instant liquid propane stops flowing through the valve,frost will form on the internal surfaces o
24、f the valve outlet. The watch shallbe stopped at this instant. The operator is forewarned of this instant ofstoppage by watching the frost line climb and roll over the lip of the valveoutlet.10.7 Disregard the observed time for the initial freeze-offrun. Quickly wipe the test valve outlet threads wi
25、th a clean, drycloth.10.8 Open the test valve to the purge position for about 15s to ensure the removal of ice from the preset opening.NOTE 3Failure to purge the apparatus with the valve open to thepurge position for about 15 s between tests will give erroneous results.Purging assures that ice forme
26、d in the preset opening in the preceding testwill be removed.10.9 Repeat the operations as described in the trial run(beginning at 10.4) until three successive freeze-off times agreewith each other to within 65s.NOTE 4For freeze-off times of less than 1 min, this may require asmany as seven or eight
27、 test runs.10.9.1 If the freeze-off time on three consecutive test runs is90 s or greater, the test on the product may be discontinued andthe freeze-off time recorded as greater than 90 s.10.9.2 For freeze-off times shorter than 90 s, record theaverage time for three consecutive determinations as th
28、efreeze-off time, to the nearest whole second.11. Report11.1 If the valve does not freeze off within 60 s, report theresult as “pass” in accordance with this test method. If thevalve does freeze off within 60 s, report the result as a “fail” inaccordance with this test method.12. Precision and Bias1
29、2.1 In the case of passfail data or results from otherqualitative tests, no generally accepted method for determiningprecision or bias is currently available.NOTE 5Data from a series of tests conducted in 1967 indicate thefollowing:At moisture levels of 14 and 26 ppm, all valves can be expectedto gi
30、ve freeze times over 3 min; at a moisture level of 49 ppm it can beexpected that none of the valves will give freeze times over 18 s; at amoisture level of 93 ppm it can be expected that none of the valves willgive freeze times over 5 s.NOTE 6The moisture concentrations in Note 5 are believed to be
31、inparts per million (ppm) by mass, mg/kg, based on the solubility of waterin propane, which precludes the concentrations from being “ppm byvolume.”12.2 BiasThe procedure in this test method for measuringdryness of propane has no bias because the value of dryness isdefined only in terms of this test
32、method.13. Keywords13.1 dryness; freeze valve; propane; waterD2713 112SUMMARY OF CHANGESSubcommittee 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.(1) Added a new Note 6 to clarify the units of water con
33、cen-tration used in Note 5.(2) Revised 10.9-10.9.2 to reduce the maximum test time to 90s 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 sta
34、ndard 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 reviewed every five years an
35、dif 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 technical committee,
36、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 Conshohocken, PA 19428-295
37、9,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/).D2713 113
