ASME MFC-10M pdf free download

ASME MFC-10M-2000 pdf free download.METHOD FOR ESTABLISHING INSTALLATION EFFECTS ON FLOWMETERS.
5 STANDARD REFERENCE CONDITIONS
5.1 Description
The process of establishinginstallationeffects involves the comparisonof the performanco thatobtainedin a standardeferencecondition.This document allows for two standardreferenceconditions.One is basedon having specfic, well-ddined flow patternn the test installation(Basic Reference Condition), and the other is based on the constancy of flowmeter performancIong the pipe (Working Reference Condition).
5.1.1 Basic Reference Condition. The Basic ReferenceCondition exists when the fluid velocity pattern at the flowmeteris identica Ito that which would exist if the meterwere installedin a conduitrunningfull and steadywith unlimitedlengthsof straightupstream and downstreanpipe. Such a flow patterns characterized by zero time-averagedadial and azimuthalfluid velocity componentand an axisymmetricaxial velocity prcfile that is independentof axial position. These componentBan be consideredo be zero if theiraverage values are zero to within the measurementincertainty or if they are negligibleto within 0.01% of the average flow velocity. The exact axial velocity prcfile depends on the inner wall roughnessof the pipe (see ASME B46.1-1985) and the Reynolds numberof the flow.
The above flow pattern which ddines the Basic Reference Condition is often describedas one which is steady,free from swirl, and havinga fully-deveLoped axial velocity prcfile.
5.1.2 Working Reference Condition. From a practicalstandpointhe ach ievemen nd/oNerification of Basic ReferenceConditionsmay be limited by the test flow facility and/or instrumentationWhen such limitationsexist, a working referenceshould be established. The method for establishingthe existence of this referenceconditionis marked lyd ifferentfrom that for the Basic Reference Condition. Here flowmeter performanceatherthana speclic flow patternis used as the criterion. Speclically, the Working Reference Conditionis achievedwhen the flowmeterperformance is independenbf orientatiomnd axial location of the flowmeteralong the pipe.
NOTE: Ideally, theflowmeterperformancchievedunderthe Working Reference Condition will not differ from that which would be observed if the flowmeter were installed in a Basic Reference Condition. This is so even though the flow patternspresentin the working reference condition may in some cases differ from those in the Basic Reference Condition. The explanationfor this lies in the fact that different flowmetershave different sensitivitiesto flow patterns.As a consequencef this differing sensitivity, the lengths of straight upstreamand downstrearrpi ping requiredto achieve the Working ReferenceConditionwill dependon the type of flowmeter being tested,as well as the test installation.A flowmeter that is fairly insensitive to flow pattern will require only short straight lengths of adjacentpiping.
5.2 Experimental Methods for Establishing Standard Reference Conditions
There are two ways to establisireferenceconditions in this Standard.They are describedin the following su bparagraphsThe first of these is more fundamental while the second is more practicaland perhapseasier to accomplishin most circumstances.
5.2.1 Establishing a Basic Reference Condition. For a given flow facility, minimuntraighengths of pipe upstreamand downstrearmf the meterare to be determinedsuch that for an installation change beyond those minimum lengths of pipe, the timeaveragecfrad ialand azi mutha Fluid velocitycomponents are zero and the axial velocity prdile remains unchanged.By comparingthis unchanginxial, velocity prcfile with thosein the literatu rsee works by Schlicting, Pao, Coles, Hines, Tennekes, Bogue, and Fluid Meters, in Section 2), the effective inner pipe wall roughnesscan be determined.On the other hand, if the pipe roughnesss alreadyknown,the existenceof a fully-developecbxial velocity prdile can be established directLy by comparingthe measurecrctile with those in the literature.
Measurementsof the local fluid velocity can be carried out using standardtechniquessuch as pitot tubes,hot wire or hot film anemometer4ser Doppler velocimeters,etc. (See, for example, ISO 3966, ISO 7194, ASME PTC 11, and similar references.)
A Basic Reference Condition can be establishecby following the steps outlined below, If necessary, a limited test program is permittedprovided that all of the limitationsare documented.
Step 1. Using calibratiorproceduresstablislthat
the velocity measuremeninstrumentation is operatingroperlyandquantifyits uncertainty.
Step 2. Install the velocity measuremenprobe in the pipe with any convenient upstream straightpipe length,but with at leastfour pipediameteengthf straighipipedownstreamof the probe.
Step3. If instrumentatiomllows, measureat a nominalf low rate the radialand azimuthal velocity corn ponentt ten or more locations in the cross-sectionalplane. If the time-averagedialues at any given location are not equalto zero within the measurement uncertainty, then Basic Reference Conditionsdo not exist. In this case, proceed to Step 6.ASME MFC-10M pdf download.