1、Designation: D6624 19Standard Practice forDetermining a Flow-Proportioned Average Property Value(FPAPV) for a Collected Batch of Process Stream MaterialUsing Stream Analyzer Data1This standard is issued under the fixed designation D6624; the number immediately following the designation indicates the
2、 year oforiginal adoption or, in the case of 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.INTRODUCTIONThe determination of an average property value that
3、 is representative of a batch of petroleumproduct collected and isolated in a tank or vessel has always been a challenge. Historically, theindustry practice has been to follow the appropriate procedures prescribed in Practices D4057, D5842,or D4177 to extract one sample (or a limited few, taken from
4、 top, middle, and bottom) from the tankor vessel after the content is mixed by any of several means to ensure the material is homogeneousprior to sample extraction. The extracted sample is then sent to a laboratory for analysis. Dependingon the property and its criticality, the average property valu
5、e can also be obtained by independentlyanalyzing each of the top, middle, and bottom samples and the results averaged, or, the three tanksamples are mixed and testing for the property is performed on the mixture.With the introduction of in-line blending and process stream analysis in the 1960s, the
6、potential forreal-time delivery to a pipeline, barge, ship, or tank car compartment was envisioned.To determine the average property value that is representative of a batch of product from a blendor process stream, two approaches have been developed and implemented. One depends on the use ofa compos
7、ite sampler, a vessel into which a sample of the flowing process or blended product streamis introduced at a flow-rate proportional to the flow-rate of the product stream (Practice D4177 orD7453). This sample, collected over the period of time required to generate the batch quantity ofproduct, is th
8、en analyzed using a primary test method in the laboratory. Multiple laboratory analyseson one or more aliquots of composite sample can be averaged to provide a more precise estimate ofthe property value than a single analysis.A second technique utilizes the results produced by on-line, at-line, or i
9、n-line analyticalmeasurement systems that test material from the process or in-line blended stream for the desiredproperty at regular intervals as it flows to a collection tank, pipeline, or shipping compartment. Todetermine the average property value of all the material collected (or shipped) at an
10、y time during theproduction process, a unique real time flow-proportioned averaging technique evolved. By appropriateselection of a production time period or cycle, the average property value for the collected (or shipped)material at any time in the production or shipment cycle is obtained by recurs
11、ively calculating aflow-proportion average using all available property values from the analytical measurement systemand the measured incremental quantity of product flow associated with each cycle. The determinationof this flow-proportioned average property value is the subject of this practice.Cop
12、yright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United StatesThis international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for theDevelopment of Internat
13、ional Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.11. Scope*1.1 This practice covers a technique for calculating aflow-proportioned average property value (FPAPV) for a batchof in-line blended product or process stream mate
14、rial that iscollected over time and isolated in a storage tank or vessel,using a combination of on-line or at-line measurements takenat regular intervals of the property and flow rates.1.2 The FPAPV methodology uses regularly collected on-line or at-line process analyzer measurements, flow, andasses
15、sment of other appropriate process measurements orvalues, to calculate a flow-proportioned average property valuein accordance with flow quantity units of material produced.1.3 When the collecting vessel contains a heel (retainedmaterial prior to receipt of the production batch), both theproperty va
16、lue and quantity of the heel material can bepredetermined and factored into the calculation of the FPAPVfor the new batch.1.4 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-
17、priate safety, health, and environmental practices and deter-mine the applicability of regulatory limitations prior to use.1.5 This international standard was developed in accor-dance with internationally recognized principles on standard-ization established in the Decision on Principles for theDeve
18、lopment of International Standards, Guides and Recom-mendations issued by the World Trade Organization TechnicalBarriers to Trade (TBT) Committee.2. Referenced Documents2.1 ASTM Standards:2D3764 Practice for Validation of the Performance of ProcessStream Analyzer SystemsD4057 Practice for Manual Sam
19、pling of Petroleum andPetroleum ProductsD4177 Practice for Automatic Sampling of Petroleum andPetroleum ProductsD5842 Practice for Sampling and Handling of Fuels forVolatility MeasurementD6299 Practice for Applying Statistical Quality Assuranceand Control Charting Techniques to Evaluate AnalyticalMe
20、asurement System PerformanceD7453 Practice for Sampling of Petroleum Products forAnalysis by Process Stream Analyzers and for ProcessStream Analyzer System Validation3. Terminology3.1 Definitions:3.1.1 analysis cycle time, nperiod of time required toproperly obtain and analyze a representative sampl
21、e of theprocess stream material.3.1.2 flow-proportioned average property value (FPAPV),naverage property value of the collected material in the tankor vessel, calculated by using the flow-proportioned averagetechnique described in the practice of all measurements per-formed on aliquots of the materi
22、al while it is flowing into thetank or vessel.3.1.2.1 DiscussionThe term property as used in this prac-tice can be the physical, chemical, or performance propertymeasurements as provided by on-line or at-line analyzersystems.3.1.2.2 DiscussionThe FPAPV can include a propertyvalue contributed by mate
23、rial (commonly referred to as a tankheel) present in the collection tank or vessel before the start ofdelivery of the current process stream material. This propertyvalue can be determined using the on or at-line measurementsystem, or a different measurement system that is suitablybias-corrected to p
24、rovide statistically indistinguishable resultsfrom the on or at-line measurement system.3.1.3 fit-for-use, nproduct, system, or service that is suit-able for its intended use.3.1.4 linearly mixable, adjproperty is deemed to be lin-early mixable in a mass or volume measurement unit if theproperty of
25、the mixed material can be calculated from thequantities and properties of the materials used to produce themixture.3.1.4.1 DiscussionThe general equations describing thislinearly mixable attribute are as follows:PMIXED5A1P11A2P21A3P31A4P41.1ANPNA11A21A31A41.1AN(1)AMIXED5 A11A21A31A41.1AN(2)where:AN=
26、 quantity of material N,PN= property of material N,PMIXED= property of mixed material, andAMIXED= quantity of mixed material.3.1.4.2 DiscussionThe material being mixed can be fromthe same process stream over time.3.1.5 total analyzer system response time, ntime intervalbetween when a step change in
27、property characteristic at thesample loop inlet and when the analyzer output indicates avalue c corresponding to the 99.5 % of the subsequent changein analyzer results; the total analyzer system response time isthe sum of the sample loop lag time, the same conditioningloop lag time, and the total an
28、alyzer response time. D37644. Significance and Use4.1 Contractual or local regulation, or both, permitting, theFPAPV calculated according to this practice can be used torepresent the average property of the quantity of materialcollected.1This practice is under the jurisdiction of ASTM Committee D02
29、on PetroleumProducts, Liquid Fuels, and Lubricants and is the direct responsibility of Subcom-mittee D02.25 on Performance Assessment and Validation of Process StreamAnalyzer Systems.Current edition approved Jan. 1, 2019. Published January 2019. Originallyapproved in 2001. Last previous edition appr
30、oved in 2014 as D6624 14. DOI:10.1520/D6624-19.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.D6624 1924.2 D
31、ue to the averaging and appropriate weighting ofanalysis results, the FPAPV estimate of the property for thecollected material is expected to be more representative andmore precise than an estimate based on a small number ofanalyses on a few samples.NOTE 1For applications where the on-line analyzer
32、system result isbeing used in direct feedback control in a contiguous manner, the trueproperty distribution for a large population of batches with essentiallyidentical FPAPVs is expected to be Gaussian, centered at the FPAPVvalue, with a standard deviation that is no less than the long term siteprec
33、ision standard deviation of the analyzer system.4.3 If the measured property value is used to predict anotherproperty value through the use of an appropriate correlationequation, the FPAPV can also be used as a suitable predictionof that property.4.4 The most recently updated FPAPV can be used torep
34、resent the property of the material currently accumulated inthe tank or vessel for process control or material dispositiondecisions, or both.5. General Requirements5.1 The analytical and flow measurement instrumentationsystems shall be installed in compliance with the principles setforth in API TP-5
35、50.35.2 The property being measured shall be linearly mixablewithin the range of the property measurements used to calcu-late FPAPV, and with respect to the quantity units (volume ormass).5.3 The integrity of the design, physical components andassemblies of both the analytical measurement system (in
36、clu-sive of the sampling subsystem), and the instrumentation forflow quantity measurement shall be determined and docu-mented at the time of commissioning and at regular intervalsthereafter. Factors to be addressed shall include, but not belimited to, the following:5.3.1 The sampling system design a
37、nd operation shall en-sure a sample representative of the process stream is deliveredto the applicable process stream analyzer.5.3.2 The process stream shall have dynamics such thatthere is no substantial change in the property over the timeperiod required to produce the analytical measurement syste
38、mresult used for each FPAPV update calculation.5.3.3 Analyzer functions shall be in proper condition toproduce accurate property measurement results.5.3.4 During the calculation of FPAPV, inferential or othervalidation strategies shall be in place to ensure the analyticalmeasurement system results a
39、re representative of the materialin the process stream. The effectiveness of these strategies shallbe supported by data.NOTE 2Examples of these strategies can include, but are not limitedto, the following: monitoring of appropriate system parameters to ensureeach sample is representative of the manu
40、facturing process stream beinganalyzed; continuous comparison of an expected value of the streammeasured versus actual result; monitoring for unusually large or unusuallysmall changes of analytic data; monitoring of key analytical instrumen-tation parameters.5.3.5 Fit-for-use condition of the flow q
41、uantity measure-ment instrumentation shall be regularly verified using suitableequipment and apparatus.5.4 The analytical measurement system shall becommissioned, validated, and thereafter regularly monitoredusing a suitably designed internal quality assurance programthat meets the appropriate requi
42、rements and criteria of PracticeD3764 and the techniques of Practice D6299.NOTE 3It is recommended that a statistician be consulted to ensure theproper application of Practices D6299 and D3764.5.5 The final FPAPV shall be calculated based on fit-for-usedata obtained from at least 90 % of the materia
43、l collected.5.5.1 For the balance of the volume (up to 10 %) that has nofit-for-use analyzer data, for the purpose of calculating FPAPV,an estimate based on knowledge of the manufacturing process,or another equivalent measurement, or both, shall be used. Themaximum error associated with this estimat
44、e that is deemedacceptable by this practice shall be no more than 2.5 % of thetrue property value.5.5.2 For measurement systems that are operated continu-ously and not started up nor shut down in batch mode insynchronization with the manufacturing process, the quality ofthe initial unmeasured volume
45、 can be estimated by applyingthe analyzer result after waiting the total analyzer systemresponse time (Practice D3764) from the initiation of themanufacturing process.5.6 For measurement systems that are operated in batchmode in synchronization with the manufacturing process (thatis, started up and
46、shut down with the manufacturing process),the statistical control status of the FPAPV measurement systemshall be validated in accordance with Practice D6299 (orequivalent) at least once for each batch, preferably in thebeginning. The frequency of in-statistical-control validationwhen the manufacturi
47、ng process is active shall commensuratewith the established stability of the measurement system.5.7 If the FPAPV is used as a surrogate or predictor ofanother measurement system (such as a laboratory testmethod), the fit-for-use of the FPAPV shall be initially vali-dated with at least 15 data points
48、 using the control chartapproach described in Practice D6299. In this case, thedifference between test results from aliquots of material that areobtained and analyzed with the measurement process (testmethod) that the FPAPV is intended to represent versus theactual calculated FPAPVs are assessed. Th
49、is validation shall besubsequently carried out as part of a statistical quality assur-ance program meeting the requirement and guidelines ofPractice D6299 for system stability.NOTE 4It is recommended that a statistician be consulted to ensure theproper application of Practice D6299.5.8 If the FPAPV is used to predict another property valuethrough the use of a correlation equation, the correlationequation shall be validated in accordance with PracticesD3764, D6299, or other appropriate statistically equivalenttechniques.3Part II Process Stream Analyzers, Manual on
