ASME MFC-1M:2003 pdf download GLOSSARY OF TERMS USED IN THE MEASUREMENT OF FLUID FLOW IN PIPES
1GENERAL
1.1 Scope
This Standard consists of a collection of definitionsof those terms that pertain to the measurement of fluidflow in pipes. Only those terms of general usage havebeen included. Terms having unique meaning whenapplied to specific meters should be included in a glos-sary within the specific flowmeter standard.
12 Organization
This Standard is organized so that all of the termspeculiar to a particular method of fluid measurementare collected together in a separate section. Terms per-taining to basic fluid flow concepts and properties aredefined in para. 2. Terms pertaining to the estimate ofuncertainty of a flow rate measurement are defined inpara. 3. General terms applying to flowmeters aredefined in para. 4. Terms relating to specific types offlowmeters are defined in paras. 5, 6, and 7. Symbolsnormally applied to various quantities are tabulated inTable 1.
1.3 References
This Standard was compiled from many sourcesincluding various reports and standards from The American Society of Mechanical Engineers (ASME)TheAmerican Gas Association (AGA) the American Petroleum Institute (API) the Instrument Society of America(ISA), the British Standards Institute (BSI), and the Inter-national Organization for Standardization (ISO)
2 GENERAL TERMS IN FLUID MECHANICS
2.1 Base Pressure
A specified reference pressure to which a fluid volumeat flowing conditions is reduced for the purpose of bill-ing and transfer accounting. [It is generally taken as14.73 psia (101.560 kPa) by the gas industry in the UnitedStates.
2.2 Base Temperature
A specified reference temperature to which a fluidvolume at flowing conditions is reduced for the purposeof billing and transfer accounting.It is generally takeras 60°F (15.56°C) by the gas industry in the UnitedStates.]
2.3 Base Volume
Volume of a fluid at base pressure and temperature
2.4 Cavitation
The implosion of vapor bubbles formed after flashingwhen the local pressure rises above the vapor pressureof the liquid. See also flashing (para. 2.8)
2.5 Coanda Effect
Effect that occurs when a jet of fluid adheres to anearby solid surface.
2.6 Doppler Effect
Apparent change in the frequency of radiation due torelative motion between a primary or secondary sourceand the observer.
2.7 Dynamic Pressure
The increase in pressure above the static pressure thatresults from the complete isentropic transformation ofthe kinetic energy of the fluid into potential energy. Itis equal to the product ou, where p is the fluid densityand v is the fluid velocity.
2.8 Flashing
The formation of vapor bubbles in a liquid when thelocal pressure falls to or below the vapor pressure of theliquid, often due to local lowering of pressure becauseof an increase in the liquid velocity. See also cavitation(para.2.4).
2.9 Flow Conditioner
General term used to describe any one of a variety ofdevices intended to reduce swirl and/or to regulate thevelocity profile.
2.9.1 Flow Straightener. Flow conditioner inserted ina pipe to eliminate or reduce swirl.
2.9.2 Profile Regulator. Flow conditioner inserted ina pipe to reduce the straight length required to achievefully developed velocity distribution.