1、Manual of PetroleumMeasurement StandardsChapter 3Tank GaugingSection 2Standard Practice for Gauging Petroleum and Petroleum Products in Tank CarsFIRST EDITION, AUGUST 1995REAFFIRMED, MAY 2013Manual of PetroleumMeasurement StandardsChapter 3Tank GaugingSection 2Standard Practice for Gauging Petroleum
2、 and Petroleum Products in Tank CarsMeasurement CoordinationFIRST EDITION, AUGUST 1995REAFFIRMED, MAY 2013iiSPECIAL NOTES1. API PUBLICATIONS NECESSARILY ADDRESS PROBLEMS OF A GENERALNATURE. WITH RESPECT TO PARTICULAR CIRCUMSTANCES, LOCAL, STATE,AND FEDERAL LAWS AND REGULATIONS SHOULD BE REVIEWED.2.
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8、roleum InstituteiiiFOREWORDAPI publications may be used by anyone desiring to do so. Every effort has been madeby the Institute to assure the accuracy and reliability of the data contained in them; however,the Institute makes no representation, warranty, or guarantee in connection with this publi-ca
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10、,Exploration and Production Department, American Petroleum Institute, 1220 L Street,N.W., Washington, D.C. 20005.vCONTENTSPageCHAPTER 3TANK GAUGINGSECTION 2STANDARD PRACTICE FOR GAUGINGPETROLEUM AND PETROLEUM PRODUCTS INTANK CARS3.2.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . .
11、. . . . . . . . . . . . . . . . . . . . . . . . . . . .13.2.2 Scope . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13.2.3 Significance and Use . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
12、. . . 13.2.4 Safety and Health Considerations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13.2.5 Physical Characteristics and Fire Considerations . . . . . . . . . . . . . . . . . . . . . . . . . 13.2.6 Normative References . . . . . . . . . . . . . . . . . . . . . . .
13、. . . . . . . . . . . . . . . . . . . . . . 13.2.7 Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23.2.8 Measurement Equipment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23.2.8.1 Liqui
14、d-Level Measurement Equipment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33.2.8.2 Temperature Measurement Equipment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33.2.9 Liquid-Level Measurement Procedures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
15、.2.9.1 Gauge Tape and Bob Procedure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33.2.9.2 Portable Measurement Unit Procedure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33.2.9.3 Slip-Tube Gauging Procedure . . . . . . . . . . . . . . . . . . . . . . . . . .
16、. . . . . . . . . . . 33.2.9.4 Magnetic Gauging Procedure (Rod Type) . . . . . . . . . . . . . . . . . . . . . . . . . . . 33.2.9.5 Magnetic Gauging Procedure (Tape Type) . . . . . . . . . . . . . . . . . . . . . . . . . . . 73.2.10 Temperature Measurement Procedure . . . . . . . . . . . . . . . . .
17、 . . . . . . . . . . . . . . . . 73.2.11 Sampling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73.2.12 Reading Tank Car Capacity Tables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73.2.13 Reporting . . . . . .
18、 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7APPENDIXTYPICAL RAIL TANK CAR CAPACITY TABLES . . . . . . . . . . . . . . . 9Figures1Non-Pressure Tank Cars . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22aS
19、lip-Tube Gauging Device Assembly With Quick-ReleaseCover for Compressed Cars . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42bSlip-Tube Gauging Device Assembly for CompressedGas Cars . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
20、 . . . . . . . . . . . . . . . 53Rod-Type Magnetic Gauging Device . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64Tape-Type Magnetic Gauging Device . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8A1Typical Rail Tank Car Capacity Tables . . . . . . . . . . .
21、 . . . . . . . . . . . . . . . . . . . 103.2.1 IntroductionThis standard provides a uniform method for measuringliquids and liquefied gases in tank cars by liquid levelmeasurement. Measurement of both vapor space and liquidlevel are described.3.2.2 ScopeTank car contents may be measured by three met
22、hods:railroad scale weighing, metering, and liquid level measure-ment. This standard describes only the equipment for and theprocedures of the liquid level method of measurement.When tank cars can be opened for manual measurements,gauge tapes and bobs may be used to measure the level ofliquid conten
23、ts. When tank cars cannot be opened forgauging contents, closed-system measurement equipmentmust be used for gauging. This standard describes gaugingand temperature measurement equipment used in both openand closed measurement systems.3.2.3 Significance and UseVolumes based on liquid level measureme
24、nts in tank carsare used for commercial purposes and to indicate compliancewith regulations regarding weight and volume. The proce-dures in this standard are intended to reduce variability in theresults of measurement and sampling operations whencomparing loading terminal data to unloading terminal
25、data.3.2.4 Safety and Health ConsiderationsCaution: All applicable safety and health procedures shouldbe consulted. Considerations should include, but are notlimited to, potential electrostatic and other fire and explosionhazards, potential personnel exposure (for example, expo-sure limits, hazard c
26、ommunication, training, associatedprotective clothing and equipment requirements, and workpractices), and potential explosive and toxic hazards associ-ated with a tank cars atmosphere. The physical characteris-tics of the commodity and existing operational conditionsshould be evaluated, and applicab
27、le international, federal,state, and local regulations should be observed. Safety proce-dures designated by the employer and other concernedparties should also be observed. The Association of Amer-ican Railroads Manual of Standard Recommended Practicesand API publications provide additional safety i
28、nformationand should be consulted.Caution: Petroleum vapors and associated substances mayalso involve potential toxicity, including hydrogen sulfidevapors from “sour” crude. Petroleum vapors with highconcentrations of hydrogen sulfide may cause unconscious-ness or death. During and after the opening
29、 of the manway,one should stand so that vapor inhalation is minimized.Harmful vapors or oxygen deficiency cannot be detectedsafely by smell, visual inspection, or judgment. Appropriateprecautions should be used for protection against toxicvapors or oxygen deficiency. Procedures should be devel-oped
30、to provide for appropriate exposure monitoring,personal protective equipment, and emergency rescueprecautions. When necessary, suitable respirator protectionshould be worn prior to entering the gauge site and duringthe gauging procedure.3.2.5 Physical Characteristics and FireConsiderationsCaution: P
31、ersonnel involved with the handling of petroleum-related substances (and other chemical materials) should befamiliar with their physical and chemical characteris-ticsincluding the potential for fire, explosion, and reac-tivityand appropriate emergency procedures, as well aspotential toxicity and hea
32、lth hazards. They should complywith individual company safe operating practices and local,state, and federal regulations. Personnel should be alert toavoid potential sources of ignition; they should keepcontainers of materials closed when not in use.3.2.6 Normative ReferencesAPIManual of Petroleum M
33、easurement Standards (MPMS)Chapter 1, “Vocabulary”Chapter 3, “Tank GaugingMethod of GaugingPetroleum and Petroleum Products”Chapter 5, “Metering”Chapter 7, “Temperature Measurement”Chapter 8, “Sampling”Chapter 12, “Calculation of Petroleum Quantities,”Section 1A, “Calculation of Static Petroleum Qua
34、ntities in Upright Cylindrical Tanks and Marine Vessels”The Association of American Railroads1Manual of Standard Recommended PracticesChapter 3Tank GaugingSECTION 2STANDARD PRACTICE FOR GAUGING PETROLEUM AND PETROLEUMPRODUCTS IN TANK CARS11The Association of American Railroads, 50 Frank Street, N.W.
35、, Wash-ington, D.C. 20001-1564.2CHAPTER 3TANK GAUGING3.2.7 Definitions3.2.7.1 A capacity table (also, tank capacity table, calibra-tion table) is a table showing the tank car capacities orvolumes for various liquid levels measured at the referencegauge point.3.2.7.2 Dome tank cars are non-pressure t
36、ank cars with anexpansion trunk (dome) at the top center of the tank car toprovide space for expansion of the liquid in the car. Themanway opening is on the dome.3.2.7.3 Domeless tank cars are tank cars with the manwayopening attached directly to the top of the tank car shell (seeFigure 1).3.2.7.4 I
37、nterior lining is the surface coating applied to theinterior of a tank car shell to prevent contents fromcontacting the metal shell. Linings may be damaged ifgauging equipment is not used carefully.3.2.7.5 Magnetic gauging device (also, magnetic floatgauge) is a gauging device fitted to a tank car t
38、o permitmeasuring the liquid level in the car without opening the carto the atmosphere. The device consists of two magnets: onefitted inside a float and one affixed to a graduated gauge rodor tape. When the two magnets link, the gauge is read at thereference gauge point.3.2.7.6 Markers are metal liq
39、uid-level indicators installedin domeless tank cars, usually at the level where the car isfilled to 98 percent of capacity; however, they are occasion-ally at other levels. Markers are not accurate measurementdevices. Markers are not recommended for custody transfermeasurements.3.2.7.7 Reference gau
40、ge point (tank cars): When the tankcar can be opened for liquid level measurement, the refer-ence gauge point is at the top edge of the manway openingat the longitudinal centerline of the tank car at the point onthe manway circumference closest to the midpoint of thetank car. Tank cars that cannot b
41、e opened for liquid levelmeasurement are equipped with built-in measurementequipment. The reference gauge point in these tank carsshould be established by the manufacturer of the measure-ment equipment.3.2.7.8 Slip-tube gauging devices measure the level of pres-surized liquid in a tank car. They con
42、sist of a graduatedhollow gauge rod fitted into a gas-tight housing. The lowerend of the rod is open, and the upper end is fitted with avalve. When the lower end contacts liquid in a tank car, asmall amount of the liquid is expelled from the valve at theupper end by pressure inside the tank car.3.2.
43、7.9 Stenciled load limit is the number painted onto thesides of a tank car indicating the maximum legal weight ofits contents.3.2.7.10 Stenciled empty weight (light weight, tare) is thenumber painted onto the sides of a tank car indicating theempty weight of the car.3.2.7.11 Tank car capacity (stenc
44、iled capacity) is thenumber painted onto the ends or sides of a tank car indi-cating its shell-full capacity. Verification may be necessary.3.2.7.12 Thermometer well (thermowell) is a metal tube,sealed at the bottom, that extends into tank cars requiringclosed loading or unloading. The thermowell is
45、 filled with aheat-transferring liquid of low volatility and freeze point(usually, ethylene glycol) that transmits the temperature of thetank car contents to a thermometer lowered into the ther-mowell.3.2.8 Measurement EquipmentOnly measurement equipment that yields results that arereproducible and
46、traceable to NIST standards (or equivalentnational standards) and for which calibration records areavailable should be used to measure liquid levels.ShellManwayFigure 1Non-Pressure Tank CarMANUAL OF PETROLEUM MEASUREMENT STANDARDS 33.2.8.1 LIQUID-LEVEL MEASUREMENTEQUIPMENTGauge tape and bobs, either
47、 manual or electronic, arerecommended to measure the liquid level of tank carcontents when the tank car can be safely opened for gauging.API MPMS Chapters 3.1A and 17.2 describe manualmeasurement equipment in detail. Other measurementequipment of equivalent accuracy may be used if it meets thecriter
48、ia defined in 3.2.8.The liquid level in tank cars may also be gauged withproperly functioning equipment built into the tank car. Built-in equipment includes slip tubes, magnetic float gauges, andother measurement devices. These devices and the proce-dures for using them are described in 3.2.9.Note:
49、Since the location of markers is often approximate, markers are notrecommended for custody transfer liquid level measurement. The primarypurpose of markers in tank cars is to provide a convenient reference mark toprevent overloading a tank car by volume.3.2.8.2 TEMPERATURE MEASUREMENTEQUIPMENTTo quantify tank car volumes to a standard temperature, theobserved temperature of the contents of each car must bemeasured. Either mercury-glass thermometers or portableelectronic thermometers may be used. Temperature measure-ment equipment may be lowered directly into
