1、Designation: D 2713 07Designation: 395/98An American National StandardStandard Test Method forDryness of Propane (Valve Freeze Method)1This standard is issued under the fixed designation D 2713; the number immediately following the designation indicates the year oforiginal adoption or, in the case o
2、f revision, 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 drynessof propane products that do not contain
3、 antifreeze agents suchas, but not limited to, commercial propane and special dutypropane (see Specification D 1835).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
4、concerns, if any, associated with 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:2D 1265 Practice for Sampling Liquef
5、ied Petroleum (LP)Gases, Manual MethodD 1835 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 t
6、est valve, na specific valve designedand 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 p
7、ropane water test valve to cool the 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 r
8、esult in shorter freeze-off times. 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
9、 pressure-reducing system of special 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
10、 interfere with this test methodand 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 Propan
11、e Water Test Valve3Aspecially constructed 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 tr
12、eated. It should not be dropped, strained 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, mea
13、suring in seconds.7.3 LP Gas Sample Cylinder, having a minimum capacity of11 L (3 U.S. gal).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
14、 Dec. 15, 2007. Published January 2008. Originallyapproved in 1968. Last previous edition approved in 2001 as D 2713 91 (2001).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
15、, refer 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: D021423.1*A Summary of Changes section appears at the end of this standard.Copyright ASTM International, 100 Barr
16、 Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.7.4 Cloth, dry, clean.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 pr
17、imary hazards of handing propane are fire,explosion, and freezing “burns” due to the autorefrigeration ofLP gas as it expands9. 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 tak
18、en from the bulksupply, due 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 ta
19、ken intoa clean, dry sample cylinder (7.3). In such cases, the sampleshall be collected strictly in accordance with directions given inPractice D 1265.10. 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
20、the sample temperature. When 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 phas
21、econnection of the sample cylinder (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 (N
22、ote 2) andset 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 andclosing until a uniform frost cover has accumulated on th
23、ehousing around the outlet 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
24、 on the internal surfaces of 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 t
25、est valve outlet threads with 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.Pur
26、ging assures that ice formed 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 62s.NOTE 4For freeze-off times of less than 1 min, this may requi
27、re asmany as seven or eight test runs.10.9.1 If the freeze-off time on three consecutive test runs is3 min or greater, the test on the product may be discontinuedand the freeze-off time recorded as greater than 3 min.10.9.2 For freeze-off times shorter than 3 min, record theaverage time for three co
28、nsecutive determinations as thefreeze-time, to the nearest whole seconds.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 met
29、hod.12. Precision and Bias12.1 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
30、valves can be expectedto give 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.12.2 BiasThe procedure in this test
31、method for measuringdryness of propane has no bias because the value of dryness isdefined only in terms of this test method.13. Keywords13.1 dryness; freeze valve; propane; waterD2713072SUMMARY OF CHANGESCommittee D02 has identified the location of selected changes to this standard since the last is
32、sue(D 2713 91 (2001) that may impact the use of this standard. (Approved Dec. 15, 2007.)(1) Revised 1.1, 7.2, and 7.3.(2) Added Sections 3, 6, and 8.(3) Added 7.5.(4) Revised Sections 4, 9, 10, and 11.ASTM International takes no position respecting the validity of any patent rights asserted in conne
33、ction 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 any time by the responsi
34、ble 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 will receive careful co
35、nsideration 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 ASTM International, 100
36、 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).D2713073
