1、AN AMERICAN NATIO NAL STANDARDFlow MeasurementASME PTC 19.5-2004Performance Test CodesCopyrighted material licensed to Stanford University by Thomson Scientific(),downloaded on Oct-05-2010 by Stanford University User.No further reproduction or distribution is permitted.Uncontrolled when printed.ASME
2、 PTC 19.5-2004FlowMeasurementPerformance Test CodesAN AMERICAN NATIONAL STANDARDThree Park Avenue New York,NY 10016Copyrighted material licensed to Stanford University by Thomson Scientific(),downloaded on Oct-05-2010 by Stanford University User.No further reproduction or distribution is permitted.U
3、ncontrolled when printed.Date of Issuance:July 25,2005The 2004 edition of ASME PTC 19.5 is being issued with an automatic addenda subscription service.The use of addenda allows revisions made in response to public review comments or committeeactions to be published as necessary.This Supplement will
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11、Copyright 2005 byTHE AMERICAN SOCIETY OF MECHANICAL ENGINEERSAll rights reservedPrinted in U.S.A.Copyrighted material licensed to Stanford University by Thomson Scientific(),downloaded on Oct-05-2010 by Stanford University User.No further reproduction or distribution is permitted.Uncontrolled when p
12、rinted.CONTENTSNotice.ixForeword.xCommittee Roster.xiCorrespondence With the PTC 19.5 Committee.xiiiSection 1Object and Scope.11-1Object.11-2Scope.1Section 2Definitions,Values,and Descriptions of Terms.22-1Primary Definitions and Systems of Units.22-2Historical Definitions of Units of Measurement.22
13、-3Symbols and Dimensions.32-4Thermal Expansion.42-5Sources of Fluid and Material Data.4Section 3Differential Pressure Class Meters.193-0Nomenclature.193-1General Equation for Mass Flow Rate Through a DifferentialPressure Class Meter.193-2Basic Physical Concepts Used in the Derivation of the GeneralE
14、quation for Mass Flow.203-3Theoretical Flow Rate Liquid As the Flowing Fluid.203-4Theoretical Flow Rate Gas or Vapor As the Flowing Fluid.213-5Errors Introduced in Theoretical Mass Flow Rate by IdealizedFlow Assumptions.213-6Discharge Coefficient C in the Incompressible Fluid Equation.213-7Discharge
15、 Coefficient C and the Expansion Factor?for Gases.213-8Calculation of Expansion Factor?.223-9Determining Coefficient of Discharge for Differential PressureClass Meters.223-10Thermal Expansion/Contraction of Pipe and Primary Element.233-11Selection and Recommended Use of Differential PressureClass Me
16、ters.233-12Restrictions of Use.243-13Procedure for Sizing a Differential Pressure Class Meter.243-14Flow Calculation Procedure.243-15Sample Calculation.253-16Sources of Fluid and Material Data.27Section 4Orifice Meters.284-0Nomenclature.284-1Introduction.284-2Types of Thin-Plate,Square-Edged Orifices.284-3Code Compliance Requirements.284-4Multiple Sets of Differential Pressure Taps.284-5Machining Tolerances,Dimensions,and Markings for Orifice Plate.284-6Machining Tolerances and Dimensions for Di
