ASME MFC-10M pdf free download

ASME MFC-10M pdf free download METHOD FOR ESTABLISHING INSTALLATION EFFECTS ON FLOWMETERS
(c)The tests outlined in this Standard should coverthe pertinent range of fluid flow rates，Reynolds num-bers,etc.，of the meter to be evaluated.
NOTE: This requircmcnt can be satisfied by stating the range ofpertinent nondimensionalized parameters over which the data wereobtained (see Section 7)0.
(d)To avoid missing periodic spatial flow variations,measurements should be made at pipe lengths that arenot integer multiples of each other.
(e) All calibrations should be performed at the sameflow conditions or as close as practical to the sameconditions when comparing different test runs. Whenreducing data, corrections can be made via an indepen-dent parameter such as Reynolds number when it canbe shown that the overall effects of the different fluidconditions (temperature,pressure,etc.) and/or the fluidproperties (density，viscosity，etc.) on the tested flow-meter size and type are known and have been ac-counted for.
)All raw calibration data should be recorded andretained.
5 STANDARD REFERENCE CONDITIONS5.1 Description
The process of establishing installation effects in-volves the comparison of the performance to that ob-tained in a standard reference condition. This documentallows for two standard reference conditions. One isbased on having specific，well-defined flow patterns inthe test installation (Basic Reference Condition),andthe other is based on the constancy of flowmeterperformance along the pipe (Working Reference Con-dition).
5.1.1 Basic Reference Condition. The Basic Ref-erence Condition exists when the fluid velocity patternat the flowmeter is identical to that which would existif the meter were installed in a conduit running fulland steady with unlimited lengths of straight upstreamand downstream pipe. Such a flow pattern is character-ized by zero time-averaged radial and azimuthal fluidvelocity components and an axisymmetric axial velocityprofile that is independent of axial position. Thesecomponents can be considered to be zero if their averagevalues are zero to within the measurement uncertaintyor if they are negligible to within 0.01% of the average
flow velocity. The exact axial velocity profile dependson the inner wall roughness of the pipe (see ASMEB46.1-1985) and the Reynolds number of the flow.The above flow pattern which defines the BasicReference Condition is often described as one whichis steady, free from swirl,and having a fully-developedaxial velocity profile.
5.1.2 Working Reference Condition. From apractical standpoint,the achievement and/or verificationof Basic Reference Conditions may be limited by thetest flow facility and/or instrumentation. When suchlimitations exist,a working reference should be estab-lished. The method for establishing the existence ofthis reference condition is markedly different from thatfor the Basic Reference Condition. Here flowmeterperformance rather than a specific flow pattern is usedas the criterion. Specifically,the Working ReferenceCondition is achieved when the flowmeter performanceis independent of orientation and axial location of theflowmeter along the pipe.
NOTE: ldeally, the flowmeter performance achieved under the Work-ing Rcference Condition will not differ from that which would beobserved if the flowmeter were installed in a Basic ReferenceCondition. This is so even though the flow patterns present in theworking reference condition may in some cases differ from thosein the Basic Reference Condition. Thc explanation for this lies inthe fact that different flowmeters have different sensitivities to flowpatterms.As a consequence of this differing sensitivity,the lengthsof straight upstrcam and downstrcam piping required to achieve theWorking Reference Condition will depend on the type of flowmeterbeing tested.as well as the test installation. A flowmeter that isfairly insensitive to flow pattern will require only short straightlengths of adjacent piping.
5.2 Experimental Methods for Establishing
Standard Reference Conditions
There are two ways to establish reference conditionsin this Standard. They are described in the followingsubparagraphs. The first of these is more fundamentalwhile the second is more practical and perhaps easierto accomplish in most circumstances.
5.2.1 Establishing a Basic Reference Condi-tion. For a given flow facility, minimum straight lengthsof pipe upstream and downstream of the meter are tobe determined such that for an installation changebeyond those minimum lengths of pipe,the time-averaged radial and azimuthal fluid velocity componentsare zero and the axial velocity profileremains un-changed. By comparing this unchanging axial,velocityprofile with those in the literature (see works by Schlict-ing.Pao，Coles，Hines,Tennekes,Bogue,and Fluid