Technical SheetTS-023-VA-Bypass-eng-euMarch, 2008

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Brooks® ByPass Flowmeters

DESIGN FEATURES•Lowcostandmaintenance.•Lineairtoflowandoutputsignals.•Rangeabilityupto10:1•Continuousflowthroughbypass.•Over-rangingisharmless.•Nosealpots,nomercury,nopurgefluids.•Nocondensationchambers.

DESCRIPTIONBrooksByPassflowmetersmeasurelinearfluidflowratesinconjunctionwithanorificeplate.Thisprovidesaninexpensivemethodofmeasuringflowratesinpipesoftwoinchorlargerusingrelativelylow-costorificeplates.Thebypassflowmeterconsitsofamainlineorifice,asetoforificeflanges,aflowmeter,asecondaryorificeandbypasspiping.Asize1/2”MetalTubeMT3809orGlassTubeGT1000isusedtomeasureflowregardlessofmainlinepipesize.Seefigure1.Thepurposeofthemainlineorificeplateistocreatethepressuredifferential.Thesecondaryorificeissizedsuchthatthetotalpressuredropthoughthebypasspipingequalsthepressuredifferentialacrossthemainlineorifice.Becausethesamepressuredropexistsacrosseachline,the1/2”flowmeterinthebypasslinegivesanexactindicationofflowrateinthemainline.

TheBrooksByPassflowmeterwithitssecondaryorificeiscalibratedasaunit.MainlinedifferentialpressureandorificepracticadataisavailablefromASME,DINandmanufacturersofprimaryelements.Becausetheflowthroughthebypasslineiscontrolledbythesecondaryorifice,achangeinorificediameterchangesthedifferentialranges.BrooksByPassflowmeterunitsaremadefor“standard”differentialrangeswithinterchangeableorifices.

MATERIALS OF CONSTRUCTIONMeteringtube: GT1000:Borisilicateglass MT3809:316Stn.Stl.(dual

certified),Monel500, HastelloyC,HastelloyB,Titanium

Gr.IIFloat: GT1000:316LStn.Stl. MT3809:316LStn.Stl.,Monel500,

HastelloyC, HastelloyB,TitaniumGr.IIFittings: GT1000:Brassor316LStn.Stl. MT3809:316Stn.Stl.(dualcertified)O-rings: GT1000:Viton,Buna,Kalrezor

EPDM MT3809:Viton,TeflonRangeorifice: 316Stn.stl.,Monel500,HasttelloyC,

HastelloyB,TitaniumGr.II

Figure 1 ByPass construction with model MT 3809

3809MT

MAINLINEORIFICE

1/2" PIPE

METAL TUBEMODEL 3806

SECONDARYORIFICE

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FLOW CAPACITIES

Flowcapacitiesdependontheallowabledifferentialpressureandthetypeofprimaryelementsused.Table1belowshowtheflowswhenusedasprimaryunita,flatplateconcentricorificewithpipeorflangepresuretaps,standardpipeandisbasedonadiameterratio(diameterratioisorificeboredividedbypipediameter)of0.70.Forotherdiameter-ratio’sseetable2.Themaximumadvisedratiois0.75andtheminimum0.35,preferableisaratiobetween0.50and0.65,i.e.max.flowbetweenapprox.50%and80%fromthetablebelow.

Table 1 Maximum Capacities For Air And Water

Notes:1) Waterflowsaregivenat20°Candaviscosityof1cP.2) Airflowsaregivenwithasupplypressureat6bargageandtemperature20°C.

Forotherfluidsorconditionspleasecontactfactory.

Table 2 Max. Capacity Correction For Other Diameter Ratio’s

Table 3 Rangeability For Various Brooks Flowmeters

DIFFERENTIAL PRESSURE kPa Nominal diameter 12,5 25 50 100 mainline Water Air Water Air Water Air Water Air pipe(mm) m3/h m3n/h m3/h m3n/h m3/h m3n/h m3/h m3n/h 50 13 1185 19 1730 26 2520 38 3470 80 29 2130 41 3000 59 4260 83 6000 100 51 3630 71 5210 102 7260 143 10420 125 78 5680 111 8070 156 11370 222 16110 150 110 8210 156 11530 220 16430 310 23060 200 199 14370 280 20540 390 28750 560 41080 250 310 22750 440 31600 620 45500 880 63200 300 440 31600 620 44280 890 63200 1260 88480 350 600 38870 860 52900 1210 75100 1720 105800 400 790 49240 1130 69260 1580 97800 2270 13900 500 1240 77160 1770 110080 2490 155300 3540 221200

d/D % max. capacity as stated in table 1

< 0.34 notrecommended 0.35 22 0.40 29 0.50 46 0.60 47 0.70 100 0.75 118

Differential Model GT1000 with Model GT1000 with Model MT3809 pressure float8-RV-3 float8-RV-14 float8-V-51(A) kPa inches WC range scale range range scale range range scale range 12,5 50 10:1 10%-100% 3.3:1 30%-100% n.a. 25 100 10:1 10%-100% 4:1 25%-100% n.a. 50 200 10:1 10%-100% 5:1 20%-100% 4:1 25%-100% 100 400 10:1 10%-100% 10:1 10%-100% 5:1 20%-100%

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ByPassflowmetertypeGT1000andMT3809

MoreinformationregardingtheBrooksByPassflowmeterscanbefoundintheirProductDataSheets(PDS)

GT 1000

MT 3809

ByPass Accuracy Class2.5acc.VDE/VDI3513

Repeatability ±0.5%ofrate

Scale length 250mm

Scale inscription Milimeter,percentofmax.flowordirectreadingunitson

detachablealuminiumplate

Maximum operating pressure 20bar

Maximum operating temperature -18°Cupto121°C

Connections AccordingtoPDS

Weight Approx.2,8kgformodelGT1000

Approx.3kgformodelGT1000withalarm

ByPass Accuracy Class2.5acc.VDE/VDI3513

Repeatability ±0.25%ofrate

Scale Standard:detachablealuminiumplate(singleor

dualscales)

Optional:choiceofdirectreadingunitsorpercentage

ofmaximumflow

Maximum operating pressure 152bar

Maximum operating temperature 324°C

Connections AccordingtoPDS

Weight Approx.1,3kgformodelMT3809

BYPASS OPTIONS

Mainlineorifice

MT 3809

SECONDARYORIFICE

MAINLINEORIFICE

1/2" PIPE

GLASS TUBEMODEL 1024

SECONDARYORIFICE

Bypass construction with flanged MT 3809 Bypass construction with flanged GT 1000

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E-Mail BrooksAm@BrooksInstrument.comwww.BrooksInstrument.com

E-Mail BrooksEu@BrooksInstrument.com E-Mail BrooksAs@BrooksInstrument.com

DIMENSIONALDRAWINGS(inmm)

1/2" NPT-FIN / OUTLET CONN.

fitting withsecondaryorifice

hex 46mm

45

410

500 ±1

105

90

34 88

72

1/2" NPT-F

1/2" NPT-F

108

260 ± 3

35

158fitting withsecondary

orifice

MT 3809 for bypass construction GT 1024 for bypass construction

BROOKS LOCAL AND WORLDWIDE SUPPORT Brooksiscommittedtoassuringallofourcustomersreceivetheidealflowsolutionfortheirapplication,alongwithoutstandingserviceandsupporttobackitup.Weoperatefirstclassrepairfacilitieslocatedaroundtheworldtoproviderapidresponseandsupport.Eachlocationutilizesprimarystandardcalibrationequipmenttoensureaccuracyandreliabilityforrepairsandrecalibration.TheprimarystandardcalibrationequipmenttocalibrateourflowproductsiscertifiedbyourlocalWeightsandMeasuresAuthoritiesandtraceabletotherelevantInternationalStandards.Visit www.BrooksInstrument.com to locate the service location nearest to you.

START-UPSERVICEANDIN-SITUCALIBRATIONBrooksInstrumentcanprovidestart-upservicepriortooperationwhenrequired.Forsomeprocessapplications,whereISO-9001QualityCertificationisimportant,itismandatorytoverifyand/or(re)calibratetheproductsperiodically.Inmanycasesthisservicecanbeprovidedunderin-situconditions,andtheresultswillbetraceabletotherelevantinternationalqualitystandards.

CUSTOMER SEMINARS AND TRAININGBrooksInstrumentcanprovidecustomerseminarsanddedicatedtrainingtoengineers,endusersandmaintenancepersons.Pleasecontactyournearestsalesrepresentativeformoredetails.

HELP DESKIncaseyouneedtechnicalassistance: Americas 1-888-554-FLOW Europe +(31)-318-549-290WithinNetherlands 0318-549-290 Asia +011-81-3-5633-7100

DuetoBrooksInstrument'scommitmenttocontinuousimprovementofourproducts,allspecificationsaresubjecttochangewithoutnotice.