ASTM D1265-2011 Standard Practice for Sampling Liquefied Petroleum (LP) Gases Manual Method《液化石油气(LP)手工取样的标准操作规程》.pdf

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1、Designation: D1265 11Standard Practice forSampling Liquefied Petroleum (LP) Gases, Manual Method1This standard is issued under the fixed designation D1265; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision.

2、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 practice covers equipment and procedures forobtaining a representative sample of specification LiquefiedPetroleum Gas (LPG), su

3、ch as specified in SpecificationD1835, GPA 2140, and comparable international standards.1.2 This practice is suitable for obtaining representativesamples for all routine tests for LP gases required by Specifi-cation D1835. In the event of a dispute involving sampleintegrity when sampling for testing

4、 against SpecificationD1835 requirements, Practice D3700 shall be used as thereferee sampling procedure.1.3 This practice may also be used for other Natural GasLiquid (NGL) products that are normally single phase (NGLmix, field butane, etc.), defined in other industry specificationsor contractual ag

5、reements. It is not intended for non-specification products that contain significant quantities ofundissolved gases (N2,CO2), free water or other separatedphases, such as raw or unprocessed gas/liquids mixtures andrelated materials. The same equipment can be used for thesepurposes, but additional pr

6、ecautions are generally needed toobtain representative samples of multiphase products (seeAppendix X1 on Sampling Guidelines in Practice D3700).NOTE 1Practice D3700 describes a recommended practice for obtain-ing a representative sample of a light hydrocarbon fluid and the subse-quent preparation of

7、 that sample for laboratory analysis when dissolvedgases are present. Use of Practice D1265 will result in a small butpredictable low bias for dissolved gases due to the liquid ventingprocedure to establish the 20 % minimum ullage.1.4 This practice includes recommendations for the locationof a sampl

8、e point in a line or vessel. It is the responsibility ofthe user to ensure that the sampling point is located so as toobtain a representative sample.1.5 The values stated in SI units are to be regarded asstandard. No other units of measurement are included in thisstandard.1.6 This standard does not

9、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 and health practices and determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:

10、2D1835 Specification for Liquefied Petroleum (LP) GasesD3700 Practice for Obtaining LPG Samples Using a Float-ing Piston Cylinder2.2 Other Regulations:Canadian Transportation of Dangerous Goods Regulations3GPA 2140 Gas Processors Association Liquefied PetroleumGas Specifications otherwise, determina

11、tions of mercaptans and hydro-gen sulfide, for example, can be misleading. Internal surfaces of samplecontainers and associated lines and fittings may be surface coated toreduce bare metal surfaces reacting with trace reactive components.6.1.6 Control hydrocarbon vapors vented during samplingto ensu

12、re compliance with applicable safety and environmentalregulations.7. Apparatus7.1 High Pressure Sample CylinderUse corrosion resis-tant metal sample containers certified by the authority havingjurisdiction for pressure vessels with adequate pressure ratingfor the product being sampled. Suitable mate

13、rials includestainless steel, Monel, and possibly other materials. Protectiveinternal coatings or surface treatments to render the internalsurface inert are acceptable. The size of the container dependsupon the amount of sample required for the laboratory tests tobe made. If the container is to be t

14、ransported, it shall alsoconform to specifications published in transportation legisla-tion such as U.S. CFR 49 or Canadian Transportation ofDangerous Goods Regulations, and their supplements, reis-sues, or similar regulations in other jurisdictions.NOTE 3It has been common practice to refer to LPG

15、sample contain-ers as “sample bombs.” Use of this term is discouraged because of obviousmisunderstanding by many people. Alternate names such as “pressurizedsample container” or “high pressure sample cylinder” are recommended.NOTE 4DOT 3E cylinders are exempt from requalification in somejurisdiction

16、s. Other cylinders may need to be requalified according to localregulations.7.1.1 The sample container should be fitted with an internaloutage (ullage) tube to permit release of a minimum 20 % ofthe container capacity as a liquid. The end of the containerfitted with the outage (ullage) tube shall be

17、 clearly marked.Typical sample containers are shown in Figs. 1 and 2.7.1.2 Sample containers without an internal outage (ullage)tubes are acceptable. Alternative purging and venting proce-dures to obtain a minimum 20 % ullage in the container, asdescribed in 11.2.1, are required.7.1.3 Verify the hig

18、h pressure sample cylinder and associ-ated valving for gas tightness by leak testing at a minimum of3450 kPa (500 psig) with inert gas prior to first use, wheneverpressure-containing components of the assembly are replaced,or otherwise on an annual basis.7.2 Sample Transfer Line made of stainless st

19、eel tubing orother flexible metal hose, impervious to the product beingsampled, is required. The most satisfactory line is one equippedwith two valves on the sample-container end, Fig. 1,asampling valve, A, and a vent valve, B.PROCEDURE8. Purging Sample Transfer Line8.1 Connect the ends of the sampl

20、e transfer line securely tothe product source and to Valve C (inlet) (Fig. 1)ofthecontainer. Close Valve A (sampling), Valve B (vent), and ValveC (inlet). Open the valve at the product source and purge thetransfer line by opening Valve A (sampling) and Valve B (vent).9. Purging the Sample Container9

21、.1 If the history of the sample container contents is notknown, or if traces of the previous product could affect theanalysis to be carried out, or both, use one of the following twopurge procedures:9.1.1 Ensure that Valve C (Fig. 2) and Valve D on the highpressure sample cylinder are closed. Connec

22、t a sample transferline (with closed Valves A and B) to the cylinder at Valve D andto the sample source. Maintain the cylinder in an uprightposition such that Valve C is at the top.9.1.2 Fill sample container by opening Valve A followed byValve C and Valve D until liquid issues from Valve C. At that

23、time, close Valve C, followed by Valve D and Valve A on thesample transfer line. Vent the sample transfer line by brieflyopening Valve B.9.1.3 Loosen the connection joining the sample container tothe sample line and turn container through 180 such that ValveD is at the top. Open Valves C and D and d

24、rain out liquid.D1265 1129.1.4 Return the sample container to position Valve C at thetop. Tighten connection to sample transfer line and repeat thepurging operation at least three times.9.2 In a flowing system or a suitable sample loop, thesample cylinder may be flushed online by connecting thedip-t

25、ube end of the cylinder to the higher pressure point, andthe other end back to the lower pressure point. Keep thecylinder upright with the dip tube end down to maintain liquidfilled during flushing. Flush the cylinder with at least 10 timesthe cylinder volume in a time of less than 5 min to ensure a

26、sufficient flow velocity to obtain turbulent mixing and flushingof the ullage volume area by using the dip tube as a venturimixer. The sample line shall be equipped with a suitable flowindicator to ensure an adequate flow rate throughout theflushing period.9.2.1 This procedure is particularly applic

27、able in areaswhere excessive venting of LPG to the atmosphere is notallowed.9.3 If the history of the sample container contents is knownand would not affect the analysis, use the following purgeprocedure:9.3.1 With the container in an upright position, Fig. 1, andits Valve D (outlet) at the top, clo

28、se Valve B (vent) and ValveC (inlet) and open Valve A (sampling). Open Valve C (inlet)and partly fill the container with sample by slowly opening theValve D (outlet). Close the Valve A (sampling) and allow partof the sample to escape in the vapor phase through Valve D(outlet). Close Valve D (outlet)

29、 and release the remainder of thesample in the liquid phase by opening Valve B (vent). Repeatthe purging operation at least three times.10. Transfer of Sample10.1 Position the sample container securely in an uprightposition with Valve D (outlet) at the top (Fig. 1) and bothValves C and D closed.10.1

30、.1 Close Valve B (vent), open Valve A (sampling), openValve C (inlet), and fill container with the sample. Close ValveC (inlet) and the valve at the product source. Open Valve B(vent). After the pressure is fully reduced, disconnect samplecontainer from the transfer line. Discard the sample if a lea

31、kdevelops or if either valve is opened during subsequenthandling of the sample container before performing the outage(ullage) operations outlined in Section 11.11. Sample Outage (Ullage)11.1 Immediately after obtaining the sample, place thecontainer in an upright position with the outage (ullage) tu

32、be atthe top.FIG. 1 Typical Sample Container and Sampling ConnectionsD1265 11311.1.1 Open Valve D (outlet) slightly.Allow excess liquid toescape and close the valve at the first sign of vapor, as indicatedby the first “sputtering” and change in flow behavior of thevented liquid. If no liquid escapes

33、, discard the sample and refillthe container.11.1.1.1 The cylinder shall not be stored/transported beyond80 % of its capacity with sample. Liquid sample shall bevented out to the required “reduced fill density” (typically80 % or less) prior to transport.NOTE 5Consult the authority having jurisdictio

34、n for LPG cylinderullage requirements for transport of LPG sample cylinders. Transportationlegislation such as U.S. CFR 49, Canadian Transportation of DangerousGoods Regulations, and IATA regulations limit the percent fill ofcontainers used for shipping LPG and may quote this requirement as areduced

35、 fill density or maximum fill density (normally 80 % maximumliquid fill at 15C).Alower percent fill (lower fill density) may be requiredif sampling at lower temperatures.NOTE 6Extreme low temperature sampling. LPG has a larger coeffi-cient of thermal expansion than gasoline or distillate fuels. Samp

36、ling atextremely low ambient temperatures or from cryogenic sources mayrequire additional precautions to prevent sample cylinders from becomingliquid full (liquid locked, hydraulically locked) from warming the sampleto high ambient temperature.11.1.1.2 Where immediate venting is not possible, for ex

37、-ample inside hazardous locations or with toxic materials(especially H2S), provisions shall be made to prevent tempera-ture increase prior to venting in a safe location, transfer to alarger cylinder or immediate analysis or other disposition inaccordance with the authority having jurisdiction. It is

38、 theresponsibility of the user to establish safe procedures for use inpermitted facilities that are regulated by site permits orequivalent, separate from transportation regulations.NOTE 7Improperly venting LPG vapor to establish the minimum20 % outage will result in large changes in composition of t

39、he remainingliquid due to fractional distillation. It is important that only liquid bevented from the cylinder, and that venting be stopped at the first indicationof vapor. Use of proper liquid venting technique will result in only verysmall changes in composition to the remaining liquid which will

40、not affectproduct specification results required for compliance with SpecificationD1835.11.2 For sampling containers without an internal ullagetube, the procedure in 11.2.1 may be used.FIG. 2 Typical Sample Container and Alternate Purging ConnectionsD1265 11411.2.1 One acceptable alternative procedu

41、re to use is weigh-ing the sample container immediately after filling, and creatingthe ullage before analysis. The procedure is to completely fillthe sample container using slight overflow indication to ensurecomplete filling. Without warming the sample, immediatelyweigh the container plus sample on

42、 a balance, and record grossweight. Carefully drain off liquid from the bottom of thevertically oriented container in an environmentally-approvedmanner. Then weigh the vented container, and using the tareweight of the container, estimate the ullage of the sample in thecontainer. Repeat the venting a

43、nd weighing procedures toobtain 22 6 2 % ullage of the sample.12. Checking for Leaks12.1 After eliminating the excess liquid sample so that only80 % or less of the sample remains, immerse in a water bathand check the sample cylinder for leaks. If a leak is detected atany time during the sampling ope

44、ration, discard the sample.Repair or replace the leaky container before obtaining anothersample. Alternate procedures such as use of soap/water leakdetection fluid, leak detection instruments or recording of totalcylinder weights may also be used to detect leaks.13. Care of Samples and Sample Contai

45、ners13.1 Place samples in a cool location as soon as possible.Keep them there until all tests have been completed. Discardany samples in containers which develop leaks. Protect thevalves on the sample container, either by packing the containerin a crate in an approved manner or by using a protective

46、 cap,so that accidental unseating of the valve or tampering with it isavoided.14. Keywords14.1 liquefied petroleum gases; LPG; samplingSUMMARY OF CHANGESSubcommittee D02.H0 has identified the location of selected changes to this standard since the last issue(D126505) that may impact the use of this standard.(1) Modified the definitions to comply with ASTMs Form 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/).D1265 115