1、Designation: D5287 08 (Reapproved 2015)Standard Practice forAutomatic Sampling of Gaseous Fuels1This standard is issued under the fixed designation D5287; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A
2、 number in parentheses 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 appli
3、es only to single-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, s
4、uch asTest Method D1945, should be used to acquire that informa-tion.1.5 The selection of the sampling system is dependent onseveral interrelated factors. These factors include sourcedynamics, operating conditions, cleanliness of the sourcegases, potential presence of moisture and hydrocarbon liquid
5、s,and trace hazardous components. For clean, dry gas sources,steady source dynamics, and normal operating conditions, thesystem can be very simple. As the source dynamics becomemore complex and the potential for liquids increases, or tracehazardous components become present, the complexity of thesys
6、tem selected 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 unit
7、s that are provided 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 t
8、he applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2D1945 Test Method for Analysis of Natural Gas by GasChromatographyD5504 Test Method for Determination of Sulfur Compoundsin Natural Gas and Gaseous Fuels by Gas Chromatogra-phy and Chemiluminescence2.
9、2 Other Standards:AGA Report Number 7 Measurement of Gas by TurbineMeters3API 14.1 Collecting and Handling of Natural Gas Samplesfor Custody Transfer4API 14.3 Part 2 (AGA Report Number 3)4GPA Standard 2166 Methods of Obtaining Natural GasSamples for Analysis by Gas Chromatography5ISO-10715 Natural G
10、asSampling Guidelines6NACE Standard MR-01-75 Standard Material Require-ments. Sulfide Stress Cracking Resistant-Metallic Materi-als for Oilfield 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 Stan
11、dard: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, and the necessary logic circuits tocontrol the system throughout a period of time, the purpose of1This practice is under the jurisdiction of ASTM Committe
12、e D03 on GaseousFuels and is the direct responsibility of Subcommittee D03.01 on Collection andMeasurement of Gaseous Samples.Current edition approved June 1, 2015. Published July 2015. Originally approvedin 1992. Last previous edition approved in 2008 as D5287 08. DOI: 10.1520/D5287-08R15.2For refe
13、renced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.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.,Wash
14、ington, DC 20001, http:/www.aga.org/.4Available from American National Standards Institute (ANSI), 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 fo
15、r Standardization (ISO), 1, ch. dela Voie-Creuse, Case postale 56, CH-1211, Geneva 20, Switzerland, 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,Wash
16、ington, DC 20402.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States1which 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
17、.2 representative samplea volume 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.3.1.3 retrograde condensationthe formation of liquidphase by pressure drop or temperature increase on a gas str
18、eamat 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 vessel.3.1.5 sample loopthe valve, tubing, or manifold(s), orcombination thereof, used for conducting the gas stream fromthe probe to the sampling
19、 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 the gas to besampled.3.1.7 sample vesselthe container in which the sample iscollected, stored, and transported to the analytical equipment.This is
20、also referred to as a sample cylinder.3.1.8 source dynamicschanges in gas supplies, operatingpressures, temperatures, flow rate, hydrocarbon dew point, andother factors that may affect composition or state, or both.4. Significance and Use4.1 This practice should be used when and where a repre-sentat
21、ive sample is required. A representative sample is neces-sary for accurate billing in custody transfer transactions,accurate compositional analysis of the flowing stream, gravitydetermination for flow calculations and other desired informa-tion concerning the properties of the stream contents.4.2 Th
22、is practice is not intended to preempt existing con-tract agreements or regulatory requirements.4.3 Principles pertinent to this practice may be applied inmost contractual agreements.4.4 WarningMany gages are extremely flammable andcan contain toxic substances. Caution should be taken in allaspects
23、of sample collection and handling. Sample vesselsshould only be handled in well ventilated locations away fromsparks and flames. Improper handling can result in an explo-sion or injury, or both.9Bergman, D. F., Tek, M. R., and Katz, D. L., Retrograde Condensation inNatural Gas Pipelines, American Ga
24、s Association, Arlington, VA, 1975.FIG. 1 Continuous Composite SamplersD5287 08 (2015)25. 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 prod
25、uct and the sampling practice, both internal andexternal 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
26、.5.3 When sour gas (gases that contain hydrogen sulfide orcarbon dioxide, or both) are present or suspected, consult therecommendations in NACE Standard MR-01-75.5.4 Contaminates, other than those listed above, should beidentified and addressed by the appropriate industryrecommendations, guidelines
27、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 into the center onethird of the pipeline.6.3 The sample probe should not be located within thedefined measurement region. (For example see A
28、PI 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 pipediameters downstream from any device that could causeaerosols or significant pressure drop such as orifice plates,thermowelds, elbows an
29、d 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. Sample Loop (see Fig. 4)7.1 All valves should be straight bore, full opening, stainlesssteel ball valves or full ported valves. In some ap
30、plications,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. In some applications,specially coated or passivated materials may be required.7.3 The supply line shall slope from the probe up to thesamp
31、ler 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 on the pipeline and not possessregions or traps where condensate or fluid can collect.FIG. 2 Acceptable Probe Types and InstallationsFIG.
32、3 Probe LocationsFIG. 4 Schematics of Acceptable Sample LoopsD5287 08 (2015)37.5 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 gas flowin
33、g 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 sample probe. I
34、t should be as close to the sample probe asconditions allow. Manufacturers specific instructions shouldbe referenced.8.2 MaintenanceThe sampler should be designed for easyfield maintenance. A preventative maintenance schedule asoutlined by the manufacturer should be followed.8.3 VerificationThe samp
35、ling 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 Fig. 5.8.3.1.1 Chart RecorderThe recorder should be commonlyconnected to a constant (fixed) volume sample vessel toindicate and recor
36、d 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 TracingA magnetic type system can beattached to the constant pressure piston style cylinders to trackthe movement of the internal
37、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 Pressure VerificationWhile not verifying the fill-ing time frame, a simple test of the cylinder pressure canvalidate that it was filled
38、 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 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
39、.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-floating piston-type vessel is properly installed with full pipeline pressure onthe pre-charge side, the only way product can move
40、the pistonis by way of the sample extractor. If the frequency anddisplacement are known, the pistons position is verification ofproper filling (estimated volume displacement) from thesample extractor and should be equal to the determineddisplacement in the free-floating piston vessel. 100 samplebite
41、s, 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 whenpresent.8.4 Control Methods(see Fig. 1(a) and (b) Two methodsof controlling samplers are currently recognized:8.4.1 Proportion
42、al-to-Flow ControlThis method paces thesampler with respect to flow. The controller shall be capable oftracking the pipelines flow rate accurately. This method shouldbe used when the variance of the flow rate is significant orwhen flow ceases periodically or is intermittent.8.4.2 Time-Based ControlT
43、his method paces the samplewith respect to time only. Take care to avoid sampling from astagnant source. The use of differential pressure switches andother similar devices may be used to stop the sampling process.9. Sample Vessels9.1 TypesThere are currently two recognized types, bothof which are in
44、 the shape of a cylinder:9.1.1 Variable VolumeConstant Pressure (see Fig. 1(a)These cylinders are commonly manufactured as free-floatingpiston configurations. Pipeline pressure is maintained on the“pre-charge” side of this piston. The sampler connects with the“product” side of the piston. The sample
45、r pumps the gas intothe product side of the vessel and moves the piston, thusdisplacing the pre-charge gas back into the pipeline. Thesample gas stays at or near pipeline pressure during the entiresample period. Laboratories should maintain the pre-chargepressure during the sample analysis so as to
46、maintain a constantpressure on the remaining sample, thus avoiding a phasechange due to pressure loss.FIG. 5 Chart RecorderD5287 08 (2015)49.1.2 Constant (Fixed) VolumeVariable Pressure (see Fig.1(b)These cylinders are commonly referred to as spun end,single-cavity vessels. Impact extrusion vessels
47、also fit withinthis category. If purging is required, connection on each endwould be preferable and can be provided to allow for easierhandling during approved purging procedures. Single endedcylinders maybe used as long as caution is exercised to not trapliquids in the bottom of the vessel. The pre
48、ssure 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 by various test methods, as well as materialsof construction. (See 5.2.)9.2.1 The variable-volu
49、me vessel and volumes required toobtain a representative composite sample should be used whenthe phase envelope indicates the possibility of retrogradecondensation.99.2.2 A constant-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 compositi
