1、Designation: D 5287 08Standard Practice forAutomatic Sampling of Gaseous Fuels1This standard is issued under the fixed designation D 5287; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A number in paren
2、theses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This practice covers the collection of gaseous fuels andtheir synthetic equivalents using an automatic sampler.1.2 This practice applies only to singl
3、e-phase gas mixtures.This practice does not address a two-phase stream.1.3 This practice includes the selection, installation, andmaintenance of automatic sampling systems.1.4 This practice does not include the actual analysis of theacquired sample. Other applicable ASTM standards, such asTest Metho
4、d D 1945, should be used to acquire that informa-tion.1.5 The selection of the sampling system is dependent onseveral interrelated factors. These factors include source dy-namics, operating conditions, cleanliness of the source gases,potential presence of moisture and hydrocarbon liquids, andtrace h
5、azardous components. For clean, dry gas sources, steadysource dynamics, and normal operating conditions, the systemcan be very simple. As the source dynamics become morecomplex and the potential for liquids increases, or tracehazardous components become present, the complexity of thesystem selected
6、and its controlling logic must be increased.Similarly, installation, operation, and maintenance proceduresmust take these dynamics into account.1.6 The values stated in inch-pound units are to be regardedas standard. The values given in parentheses are mathematicalconversions to SI units that are pr
7、ovided for information onlyand are not considered standard.1.7 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 and health practices and determine the applica-bi
8、lity of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2D 1945 Test Method for Analysis of Natural Gas by GasChromatography2.2 Other Standards:AGA Report Number 7 Measurement of Gas by TurbineMeters3API 14.1 Collecting and Handling of Natural Gas Samplesfor Custody Tra
9、nsfer4API 14.3 Part 2 (AGA Report Number 3)4GPA Standard 2166 Methods of Obtaining Natural GasSamples for Analysis by Gas Chromatography5ISO-10715 Natural GasSampling Guidelines6NACE Standard MR-01-75 Standard Material Require-ments. Sulfide Stress Cracking Resistant-Metallic Materi-als for Oilfield
10、 Equipment72.3 Federal Documents:CFR 49 Code of Federal Regulations, Title 49,173, 34(e), p.38983. Terminology3.1 Definitions of Terms Specific to This Standard:3.1.1 automatic sampler(see Fig. 1(a) and (b) a mechani-cal system, composed of a sample probe, sample loop, sampleextractor, sample vessel
11、, and the necessary logic circuits tocontrol the system throughout a period of time, the purpose ofwhich is to compile representative samples in such a way thatthe final collection is representative of the total composition ofthe gas stream for that period of time.3.1.2 representative samplea volume
12、 of gas that has beenobtained in such a way that the composition of this volume isthe same as the total composition of the gas stream from whichit was taken.1This practice is under the jurisdiction of ASTM Committee D03 on GaseousFuels and is the direct responsibility of Subcommittee D03.01 on Colle
13、ction andMeasurement of Gaseous Samples.Current edition approved Dec. 1, 2008. Published December 2008. Originallyapproved in 1992. Last previous edition approved in 2002 as D 5287 97 (2002).2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serv
14、iceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.3Available from American Gas Association, 400 N. Capitol St. N.W., Washing-ton, DC 20001, http:/www.aga.org/.4Available from American National Standards Institute (ANSI),
15、 25 W. 43rd St.,4th Floor, New York, NY 10036, http:/www.ansi.org.5Available from Gas Processors Association (GPA), 6526 E. 60th St., Tulsa, OK74145, http:/.6Available from International Organization for Standardization (ISO), 1, ch. dela Voie-Creuse, Case postale 56, CH-1211, Geneva 20, Switzerland
16、, http:/www.iso.ch.7Available from NACE International (NACE), 1440 South Creek Dr., Houston,TX 77084-4906, http:/www.nace.org.8Available from Superintendent of Documents, Government Printing Office,Washington, DC 20402.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohoc
17、ken, PA 19428-2959, United States.3.1.3 retrograde condensationthe formation of liquidphase by pressure drop or temperature increase on a gas streamat or below hydrocarbon dew point.93.1.4 sample extractora device to remove the samplefrom the flowing stream or sample loop and put it into thesample v
18、essel.3.1.5 sample loopthe valve, tubing, or manifold(s), orcombination thereof, used for conducting the gas stream fromthe probe to the sampling device and back to the source pipe(or atmosphere).3.1.6 sample probethat portion of the sample loop at-tached to and extending into the pipe containing th
19、e gas to besampled.3.1.7 sample vesselthe container in which the sample iscollected, stored, and transported to the analytical equipment.This is also referred to as a sample cylinder.3.1.8 source dynamicschanges in gas supplies, operatingpressures, temperatures, flow rate, hydrocarbon dew point, and
20、other factors that may affect composition or state, or both.4. Significance and Use4.1 This practice should be used when and where a repre-sentative sample is required. A representative sample is neces-sary for accurate billing in custody transfer transactions,accurate compositional analysis of the
21、flowing stream, gravitydetermination for flow calculations and other desired informa-tion concerning the properties of the stream contents.4.2 This practice is not intended to preempt existing con-tract agreements or regulatory requirements.4.3 Principles pertinent to this practice may be applied in
22、most contractual agreements.4.4 WarningMany gages are extremely flammable andcan contain toxic substances. Caution should be taken in allaspects of sample collection and handling. Sample vesselsshould only be handled in well ventilated locations away fromsparks and flames. Improper handling can resu
23、lt in an explo-sion or injury, or both.5. Material Selection5.1 The sampling system (including probes, tubing, valvingand other components) should be constructed of suitable inert,or passivated, materials that are compatible with all aspects ofthe product and the sampling practice, both internal and
24、external conditions to ensure that constituents in the fuelstream do not degrade these components or alter the compo-sition of the sampled gas.5.2 The selected material should be inert to and not absorp-tive of all expected components in the gas stream.9Bergman, D. F., Tek, M. R., and Katz, D. L., R
25、etrograde Condensation inNatural Gas Pipelines, American Gas Association, Arlington, VA, 1975.FIG. 1 Continuous Composite SamplersD52870825.3 When sour gas (gases that contain hydrogen sulfide orcarbon dioxide, or both) are present or suspected, consult therecommendations in NACE Standard MR-01-75.5
26、.4 Contaminates, other than those listed above, should beidentified and addressed by the appropriate industry recom-mendations, guidelines and standards.6. Sample Probe (see Fig. 2 and Fig. 3)6.1 The sample probe should be mounted vertically in ahorizontal run.6.2 The sample probe should penetrate i
27、nto the center onethird of the pipeline.6.3 The sample probe should not be located within thedefined measurement region. (For example see API 14.3, Part2, Paragraph 2.5.1).6.4 The sample probe should be constructed of stainlesssteel. (See also, 5.2.)6.5 The sample probe should be a minimum of five p
28、ipediameters downstream from any device that could causeaerosols or significant pressure drop such as orifice plates,thermowelds, elbows and the like.6.6 The probe should be designed using probe calculationswith regard to wake frequency and resonant vibration impact.(See API 14.1, paragraph 7.4.1)7.
29、 Sample Loop (see Fig. 4)7.1 All valves should be straight bore, full opening, stainlesssteel ball valves or full ported valves. In some applications,specially coated or passivated materials may be required.7.2 The sample loop should be14-in. (6.25-mm) or lessoutside diameter stainless steel tubing.
30、 In some applications,specially coated or passivated materials may be required.7.3 The supply line shall slope from the probe up to thesampler and not possess regions or traps where condensate orfluid can collect.7.4 The return line should slope down from the sampler toa connection of lower pressure
31、 on the pipeline and not possessregions or traps where condensate or fluid can collect.7.5 The supply line should be as short as possible, with aminimum number of bends.7.6 The sample loop should be insulated or heat traced, orboth, if ambient temperature conditions could cause conden-sation of the
32、gas flowing through the loop.7.7 Filters or strainers that could cause the sample to bebiased or altered are not allowed in the sample loop.7.8 Flow through the sample loop should be verified.8. Automatic Sampler (see Fig. 1(a) and (b)8.1 InstallationThe sampler shall be mounted higher thanthe sampl
33、e probe. It should be as close to the sample probe asconditions allow. Manufacturers specific instructions shouldbe referenced.FIG. 2 Acceptable Probe Types and InstallationsFIG. 3 Probe LocationsFIG. 4 Schematics of Acceptable Sample LoopsD52870838.2 MaintenanceThe sampler should be designed for ea
34、syfield maintenance. A preventative maintenance schedule asoutlined by the manufacturer should be followed.8.3 VerificationThe sampling personnel should be able toverify that the sample vessel was filled as planned. This can beaccomplished by several methods:8.3.1 Cylinder Filling VerificationSee Fi
35、g. 5.8.3.1.1 Chart RecorderThe recorder should be commonlyconnected to a constant (fixed) volume sample vessel toindicate and record the increased in pressure as the sampleextractor adds incremental grabs (samples) to the samplevessel. This only applies to the fixed volume vessels.8.3.1.2 Electronic
36、 TracingA magnetic type system can beattached to the constant pressure piston style cylinders to trackthe movement of the internal piston during the filling process.A 420 ma signal system (or similar technology) can bemonitored by computer systems or by preset signal verificationprocess.8.3.1.3 Pres
37、sure VerificationWhile not verifying the fill-ing time frame, a simple test of the cylinder pressure canvalidate that it was filled to pipeline line pressure.8.3.2 Verification of Sample Extractors OutputNumerousdevices are available to check the output of the sampleextractor. The devices output may
38、 be a contact closure, a 4 to20 mA signal, a power pulse, or any other type that can berecorded. This applies to all vessel types.8.3.3 Pressure TransducerLike a chart recorder, the pres-sure transducer measures the increasing pressure within a fixedvolume vessel.8.3.4 Calculation MethodWhen a free-
39、floating piston-type vessel is properly installed with full pipeline pressure onthe pre-charge side, the only way product can move the pistonis by way of the sample extractor. If the frequency anddisplacement are known, the pistons position is verification ofproper filling (estimated volume displace
40、ment) from thesample extractor and should be equal to the determineddisplacement in the free-floating piston vessel. 100 samplebites, grabs or aliquots of 0.5 cc volume should equal 50 cc inthe cylinder.) Compensation for changes in pipeline pressureand ambient temperature changes must be considered
41、 whenpresent.8.4 Control Methods(see Fig. 1(a) and (b) Two methodsof controlling samplers are currently recognized:8.4.1 Proportional-to-Flow ControlThis method pacesthe sampler with respect to flow. The controller shall becapable of tracking the pipelines flow rate accurately. Thismethod should be
42、used when the variance of the flow rate issignificant or when flow ceases periodically or is intermittent.8.4.2 Time-Based ControlThis method paces the samplewith respect to time only. Take care to avoid sampling from astagnant source. The use of differential pressure switches andother similar devic
43、es may be used to stop the sampling process.9. Sample Vessels9.1 TypesThere are currently two recognized types, bothof which are in the shape of a cylinder:9.1.1 Variable VolumeConstant Pressure (see Fig.1(a)These cylinders are commonly manufactured as free-floating piston configurations. Pipeline p
44、ressure is maintainedon the “pre-charge” side of this piston. The sampler connectswith the “product” side of the piston. The sampler pumps thegas into the product side of the vessel and moves the piston,thus displacing the pre-charge gas back into the pipeline. Thesample gas stays at or near pipelin
45、e pressure during the entiresample period. Laboratories should maintain the pre-chargepressure during the sample analysis so as to maintain a constantpressure on the remaining sample, thus avoiding a phasechange due to pressure loss.9.1.2 Constant (Fixed) VolumeVariable Pressure (seeFig. 1(b)These c
46、ylinders are commonly referred to as spunend, single-cavity vessels. Impact extrusion vessels also fitwithin this category. If purging is required, connection on eachend would be preferable and can be provided to allow for easierhandling during approved purging procedures. Single endedcylinders mayb
47、e used as long as caution is exercised to not trapliquids in the bottom of the vessel. The pressure graduallybuilds up as the sampler puts gas into the sample vessel.9.2 Vessel SelectionSeveral factors shall be considered inselecting a vessel, including phase changes, pressure, andvolumes required b
48、y various test methods, as well as materialsof construction. (See 5.2.)9.2.1 The variable-volume vessel and volumes required toobtain a representative composite sample should be used whenthe phase envelope indicates the possibility of retrogradecondensation.9FIG. 5 Chart RecorderD52870849.2.2 A cons
49、tant-volume vessel may be used when conden-sation is not a consideration.9.2.3 One atmosphere (101.325 kPa) of sample gas isnormally in the sample vessel at the start of the sampling cycle.To reduce the impact of that initial volume, at least tenadditional volumes should be collected in the sample period. Ifthe initial volume and composition is known, computer soft-ware can sometimes be used to convert raw analytic results intovalues representative of the sample stream.9.3 Vessel InstallationAll vessels should be i
