ASME MFC-22–2007 pdf download.Measurement of Liquid by Turbine Flowmeters.
1 SCOPE This Standard describes the criteria for the application of a turbine flowmeter with a rotating blade for the measurement of liquid flows through closed conduit running full. The standard discusses the following: (a) considerations regarding the liquids to be measured (b) turbine flowmeter system (c) installation requirements (d) design specifications (e) the maintenance, operation, and performance (f) measurement uncertainties This Standard does not address the details of the installation of accessory equipment used to measure pressure, temperature, and/or density for the accurate determinationofmass orbase volumes,or thoseaccesso- ries used to automatically compute mass or base volumes. 2 REFERENCES The followingis a listofpublications referenced inthis Standard. Unless otherwise specified, the latest edition shall apply. ANSI/NCSL Z540.2-1997 (R2002), U.S. Guide to Expression of Uncertainty in Measurement Publisher: NCSL International, 2995 Wilderness Place, Suite 107, Boulder, CO 80301-5404 ASME MFC-1M, Glossary of Terms Used in the Measurement of Fluid Flows in Pipes Publisher: The American Society of Mechanical Engineers (ASME), Three Park Avenue, New York, NY 10016-5990; Order Department: 22 Law Drive, P.O. Box 2300, Fairfield, NJ 07007-2300 ISO Guide to the expression of uncertainty in measurement Publisher: International Organization for Standardization (ISO), 1 ch. de la Voie-Creuse, Case postale 56, CH-1211, Gene`ve 20, Switzerland/Suisse NIST Technical Note 1297 (TN 1297), Guidelines for Evaluating and Expressing the Uncertainty of NIST Measurement Results
3 DEFINITIONS AND SYMBOLS Much of the vocabulary and many of the symbols used in this Standard are defined in ASME MFC-1M. Others that are unique in the field under consideration, or with special technical meanings are given in para. 3.1. Where a term has been adequately defined in the main text, reference is made to the appropriate paragraph. 3.1 Definitions base flow rate: flow rate converted from flowing condi- tions to base conditions of pressure and temperature, generally expressed in units of base volume per unit time (e.g., gpm, m 3 /h, etc.). base pressure: a specified reference pressure to which a fluid volume at flowing conditions is reduced for the purpose ofbillingand transfer accounting. Itis generally taken as 14.73 psia (101.560 kPa) by the gas industry in the U.S. base temperature: a specified reference temperature to which a fluid volume at flowing conditions is reduced for the purpose of billing and transfer accounting. It is generally taken as 60°F (15.56°C) by the gas industry in the U.S. base volume: volume of the fluid at base pressure and temperature. flowing pressure: static pressure ofthe fluid at the flowing condition. flowing temperature: the temperature of the fluid at the flowing condition. linearity: linearity refers to the constancy of K factor over a specified range, defined by either the pipe Reynolds number or the flow rate. A typical liquid turbine meter performance curve is shown in Fig. 1. The linear range of the turbine meter is usually specified by a band defined by maximum and minimum K factors, within which the K factor for the meter is assumed to be K mean . The upper and lower limits ofthis range can be specified by the manufacturer as a function of maximum and minimum Reynolds number ranges, a flow rate range of a specified fluid, or other meter design limitations such as pressure, temperature, or installation effects.
4.2 Output and Readout Device 4.2.1 The rate ofrevolution of the rotor is normally determinedfromtheblade passingfrequencyorbyother means that relates to the rate of rotation. 4.2.2 Turbine meter output may be mechanical, electrical, electromechanical, optical, analog, and digital. The readout devices may be of any form suitable for the application. 4.2.3 For electrical pulse output meters, the output includes the pulse detector system and all electrical con- nections necessary to transmit the indicated rotor revo- lutions outside the body for uncorrected volume registration. 5 SELECTION OF METER AND ACCESSORY EQUIPMENT FOR FLOW RATE DETERMINATION For proper selection and operation of the meter, the following information may be necessary: (a) fluid properties of the flowing stream including viscosity, vapor pressure, toxicity, corrosiveness, lubrica- tion properties, specific gravity, etc. (b) flow rate range and operational conditions includ- ing unidirectional or bidirectional flows and continuous or intermittent flows (c) performance characteristics that are required for the application including linearity over a specified flow range, repeatability at any flow rate, and improved lin- earity over a flow range (d) the flange rating, area classification,materials, and dimensions of the equipment used (e) available space for the meter installation and prov- ing facility, if required for the application (f) operating pressure ranges, acceptable pressure losses through the meter installation, and necessary con- sideration to avoid vaporization of the fluid while pass- ing through the meter