Rotary Screws Pumps

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Thenewpumpsseriesproduc0onmodel2Orepresentstheevolu0onofonehundredyearsofexperienceindesignandconstruc0onoftwinscrewsrotarypumpswithinternalorexternal0mingdevice.Thenewserieshasbeencompletelydesignedandengineeredtosupplyextremelyreliablepumps,eveniftheworkingcondi0onsarecri0cal.Thanktocomputeraidthehydraulicprofile,thecomponentsandthedimensionsarefullyop0mized.Thatmeansacompactandsolidconstruc0onwithaneasytorepairfeature.

Thepumpsseriesproduc0onmodel2Oareextremelyversa0leandcaneasymeetcustomer'srequirements.Thewiderangeofmodels,materialsofconstruc0onandassemblies,foranyspecificapplica0ons,offerareliablesolu0onsinaccordancewithAPI676standardtoo.Thepumpsseriesproduc0onmodel20areprovidedwithawearresistantinnercasingforlonglifeandtroublefreeopera0ons.Theinnercasing,casttype,canbesuppliedinawiderangeofmaterialstomatchfluidcharacteris0cs.Theouterpumpcasingisofcompactdesigntypeandprovidedwithampleflowpassagestominimizethefric0onsandincreasetheefficiency.Thecasingisdesignedforaworkingpressureupto20baratthemaximumtemperatureof200°C.Specialfeatureswithcoolingorhea0ngchamberarealsoavailableonrequest.ThenozzlesareflangetypeinaccordancewithISOorANSIstandard.Thenozzlesposi0onsareIN-LINEasstandard,SIDE-TOPareonrequestAllgasketsareconfinedO-ringtype,suppliedindifferentsynthe0cplas0cmaterials.Spiralwoundgasketscanbealsosuppliedforhightemperature.Screwrotorsaresinglebarpiece,forgedtype.Onthescrewrotor,nondriving,arelocatedthe0minggear.The0mingposi0onofthescrewsdonotrequiredanyadjustmentsincethe0minggearsareposi0onedbykeys,sothatthescrewsnevertouchwithonetoanother.Gearshavehardenedandrec0fiedteethprofilestoallowhighprecisioncouplingandsilentrunning.OversizedrollerbearingsseriesNUonthe0minggearssideandballbearingangularcontacttypeonthecouplingsidearefiWed.Thebearingscanbeeasilyremovedtoallowmechanicalsealreplacement.Thelubrica0onofthebearingisgreasetypeonthecouplingsideandoiltypeatthe0minggearsside.Oillubrica0onforbothsideisalsoavailable,includingexternalcircula0onifrequired.Awiderangeofsolu0onsaboutbearingslubrica0onandprotec0onareavailableincludingV-ringuptobearingprotectorIP66.AllmechanicalsealaresuppliedinaccordancewithAPI682standard.Cartridgetypemechanicalsealareavailableonrequest.AllpumpscanbesuppliedwithreliefvalveAPI520standard.

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Thepumpis0medtwinscrewrotarytypeanditiscomposedbyacoupleofrotoraxes,withopponentcoils,withmutualspecialoutlinethatworkinsideachambersetinthepumpcasing.Oneveryrotor,madeinonebar,twocontrastedandsynchronizedscrewsarerealizedtobalanceeveryhydraulicsthrust,andthroughexternaldevice,gearcouplewiththerotorsaresincronizedtogether.Thepumpedupfluidgoesintothepumpcasingfromtheaspira0onflangeandthendividedintwodifferentparts,a[eritisaspiredbythescrewsandpushedinaxialwaytowardthedeliveryflange.Thespecialopposedscrewsprofilecreateduringthechambersrota0onswhichconstantlypushwithoutbeatstowardthedeliverypump,inthisway,thepumpisabletotransporteverykindoffluidindependentlyfromthefluidviscosity.Thesynchronismedevice,0minggears,preventsanymetalliccontactduringrota0onandenablethepumpingofnon-lubrica0ngfluidsaswellasaggressivemedia.Thisdesignalsoallows

dryrunningandselfpriming

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Twinscrewspumps(PDpumps)createflow,centrifugalpumpscreatepressure.InaPDpump,flowiscreatedbyenclosingavolumeatsuc0on,movingittodischarge,andreleasingit.Pressureiscreatedbythesystem'sresponsetoflow.Ifdeliverypressureislowerthanrated,theflowwouldexitwithoutanyproblemforthepump..Centrifugalpumpscreatepressurebyfirstimpar0ngvelocitytothefluidwiththeimpeller,thenconver0ngthevelocitytopressurewiththevolute.Thecentrifugalpumpcannotbeworkatlowerpressurethanrated,andIftherewasnodischargeflangeconnec0on,noiseandvibra0onsstar0ngandcentrifugalpumpshallbebrokenquickly.Iftheviscosityincrease,thecentrifugalpumpsreduceitsperformance(lossofdeliverypressureandcapacity)andincreaseaabsorbedpower.InaPDpumpdeliverypressureisindipendendfromtheviscosityand,whenviscosityincrease,thepumpperformanceremaingthesameortheflowincrease.ThePDpumpsisthemostop0onwhenthefluidviscositychangeintheprocess.

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Bearinghousing,oillubricated.Solu0onwithfullyenclosedIP65bearinghousing

Engineeredandcustomsmechanicalseals

Renevablecastedliner

Screwmachinedfromonebar,onepieceonlyandanymaterial

combina0on.Dinamicallybalanced.Possibilitytohardening

threatments.Differentscrewprofilesinfunc0onofdesidered

perfomances.

Posi0velylocked0minggearsbymeanofkeys

Easymoun0ngbearings:Itispossibleremovethemechanicalsealswithoutremovingthebearings.

Castedorweldedpumpcasingavailableinhorizontalorver0calsolu0on.Possibilitytohavehea0ngjacket.

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LubeoilFueloilHydraulicOilEveryfluidwithlubricantcharacteris0cs

Selfpriming,doubleentrydesign,withinternalbearingsandsincronism0minggear,no.Onemechanicalorpackingseal

Nonlubrica0nglowandmediumviscosityandcorrosivefluid

Selfpriming,doubleentrydesign,withexternalbearingsseparatedbyseals.Compactdesignforasimplemaintenanceandceappestsolu0on.Sha[sealshallbesingleordouble.

Nonlubrica0nglowandmediumviscosity,corrosiveanddangereousfluids.

Selfpriming,doubleentrydesign,withexternalbearingsseparatedbyseals.Longsha[designsuitableforawiderangeofsealsconficura0ons.Possibilitytoinstallcartdridgedesign.

Nonlubrica0nglowandmediumviscosity,corrosiveanddangereousfluidsinheavydutyservicewithopera0ngmorethan3year.

Selfpriming,doubleentrydesign,withexternalbearingsseparatedbyseals.Strongsha[designforalldangereousfluidsinallcondi0ons.DesigntomeetAPI676andallAPI682mechanicalsealconfigura0ons.Possibilitytoworkinmixedphases.

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PumpCasin

ginstalla0o

nHorizontal(O)

Ver0cal(V)

Hea0

ngsy

stem

Horizontalinstalla0on

Ver0calinstalla0on

SideTop(S)

Inlinedesign(L)

Suc0onanddischargeflangesareinLine,atthesameplane.

Suc0onanddischargeflangesareinLine,atthesameplane.

Flangedisp

osi0on

FootHea0ng(F)

Hea0ngjacket(T)

Achamberinstalledonpumpfood,Suitableforsteamvapourorhotoil

Hea0ngjacketindoublecasing,suitableforsteamvapourorhotoil.

NoHea0ng(-)

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BearingHo

using

Labirinth

Bearingprotectors

Bronzelabirinth.

Bearingprotectorsormagne0cseals,IP67,forfullyenclosedinstalla0on.

Sealrings

Standardinstalla0on,possibilitytohaveperfluoroelastomerpolymers.

Bearingarrangementsofalltypesdonotpnlyconsistofbearingsbutincludetheassociatedcomponents,suchassha[sandhousings,aswellasseals.Theperformanceofthesealisofdecisiveimportancewherelubricantcleanlinessisconcernedandthiscleanlinesshasconsiderableinfluenceonbearingandpumplife.

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Componentmechanicalsealsinstalleddirectlyonpumpsha[tominimizedimensions.Thesealitisinstalledclosedtothebearinghousingtotohaveshortsha[extensions.MechanicalsealchambermeetDINandANSIrecomanda0on.Inthisconfigura0onitispossibletoinstallquelchbushformonitoringand/orwashingusinglowtemperaturefluidsonly.

(S)Singlemechanicalseals,compactsolu0oninopensealchamber

Componentmechanicalsealsinstalleddirectlyonpumpsha[tominimizedimensions.MechanicalsealchambermeetDINandANSIrecomanda0on.Singleordoubleconfigura0onarepossible.Inthisconfigura0onitispossibletoinstallquelchbushformonitoringand/orwashing.Openchamberinstalla0on,withseparatemechanicalsealflangetominimisesinstalla0onandmaintenanceproblems.Thischamberpermitalsowashing/coolingcapabilityforseals,butitisnotrecommendedwithlowersuc0onpressureorhighvacuumandflashingfluids.

(F)Mechanicalsealswithmechanicalsealflangeinopensealchamber

Medium/heavydutycartdridgemechanicalsealsassurehighreabilitypumpseals,andthecartridgeassemblyminimisesinstalla0onproblemstoaminimumandissuitableformostapplica0ons.MechanicalsealchambermeetDINandANSIrecomanda0on,whichhaveverylimitedradialandaxial.Singleordoubleconfigura0onarepossibleandcartdridgesolu0onminimizeinstalla0onandmaintenancethroublesandprotectthesha[bymeanofsha[sleeve.Thesesealshavealsopossibilitytoinstallquelchbushformonitoringand/orwashing.Openchamberpermitwashing/coolingcapabilityforseals,butitisnotrecommendedwithlowersuc0onpressureorhighvacuumandflashingfluids.

(C)Cartdridgemechanicalsealsinopensealchamber

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CartdridgeMechanicalSealsaccordingtoAPI682withfullyconfinedmechanicalsealchamber.APIrecommenttouseaconfinedmechanicalsealchamberbymeanofthroWlebushingwithnongallingmaterials.AllmechanicalflushingandquelchingPlanaccordingtoAPI682recomenda0on.Thepurposeofthestandardwastocaptureprovensolu0onstothemostcommonsealingapplica0onsseeninrefinerieswherewemustbeassurehighreabilityinheavydu0esservice.Nolimitsformechanicalsealflushingconfigura0on.Fullyconfinedmechanicalsealchamberassurehighreabilityalsowithmixedphasefluids.Largespacewithlongersupportsforeasymaintenance.

(A)API682cartdridgemechanicalseals

Single Single + Qelch Single + Qelch Double API 676Cartdrige

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S F C A Safety

Packingseals

✔ ✔ ✔ ✔ ✔ ✔

✔ ✔

✔ ✔ ✔

✔✔

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Products

LubricantoilsHydraulicoilsFluidwithpoororlowlubricantcapabili0esCleanfueloils.

SealsThesepumpcanbemountalltypeofsealincludingcartdridge.

Single or double seal, in according to working conditions

Short ar rigid shaft rotors, made in one piece

Renevable liner at pump casing, with several materials selection

short support for an easier maintenance

Build in satety valve

Various bearing selections, including journal type

Descrip0on

TwinscrewrotarypumpwithrenevablelinerandinternalbearingsforalllubricantfluidsorfluidswhichdonotchemicallyaWacktheinternalbearingsmaterials.Thejournalbearingscanbesupplyinseveralmaterialandinfunc0onofpumpingtemperature.Speciallydesignedforlargecapaci0esonlubeoilserviceinmarine,off-shoreorindustrialplants.

Performancedata

Workingtemperature upto150°cViscosityrange upto1500cstInletpressure upto6BarDifferen0alpressure upto16BarSpeed upto3500rpm

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Products

WaterLightchemicalandpetrochemicalproductsFuelandheavyfueloilsNonlubrican0ngfluidswithlightormediumviscosityrange.

SealsThesepumpcanbemountonlysingleordoublebacktobackmechanicalsealconfigura0on.

Compact seal chamber for a single or double seal configurazion

Short ar rigid shaft rotors, made in one piece

Renevable liner at pump casing, with several materials selection

short support for an easier maintenance

Build in satety valve

Bearing protector or V seals

Descrip0on

Twinscrewrotarypumpwithrenevablelinerandexternalbearings,incompactdesign,forallnonlubricantfluidswithlightandmediumviscosi0es.CompactsealchamberaccordingtoISO.Speciallydesignedforindustrialplantswithlowcostimpact.

Performancedata

Workingtemperature upto150°cViscosityrange upto1500cstInletpressure upto6BarDifferen0alpressure upto16BarSpeed upto3500rpm

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Products

WaterLightchemicalandpetrochemicalproductsFuelandheavyfueloilsNonlubrican0ngfluidswithlightormediumviscosityrange.

SealsAwiderangeofsealssha[designincludingflangedandcartdridge,withflushorquelchingpipes.Possibilitytoinstallsha[sleeveandthroWlebushingforadifficultssuc0oncondi0ons.

Bearing protector or V seals

Rigid shaft rotors, made in one piece

Renevable liner at pump casing, with several materials selection

Flanged or cartdridge mechanical seals

Build in satety valve

Reinforce d support housing also in carbon steel

Descrip0on

Twinscrewrotarypumpwithrenevablelinerandexternalbearings,forallnonlubricantfluidswithlightandmediumviscosi0es.Supportsandsealchamberdesignedforflangedseal.Possibili0toinstallawiderangeofflushingandorquelchingpipes.Customdesignforbearingshousingincludingcooling,deflectors,bearingprotectors,monitoringsensorsetc..

Performancedata

Workingtemperature upto200°cViscosityrange upto2500cstInletpressure upto6BarDifferen0alpressure upto16BarSpeed upto3500rpm

Various bearing lubesystems

Fully customized gearbox with various special devices, up to separate oil mist external pumps, moved by main shaft rotor

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Products

DangereousfludsChemicalandpetrochemicalproductsHydrocarbonandprocessfluidsFuelandheavyfueloilsNonlubrican0ngfluidswithlightorhighviscosityrange.

SealsSha[sealanddesignwithoutcompromise,fullyAPI676andAPI682,withallflushingorquelchingpipes,forprocesanddangereaousworkingcondi0ons.Specialintermediateflangewithseveralmaterialselec0onforaneasiermaintenance.Possibilitytomountbearingprotectorforanyindustrialatmosphere,withdustandpollu0ontoprotectbearing.

Descrip0on

Twinscrewrotarypumpwithrenevablelinerandexternalbearings,forallnonlubricantfluidswithlightandmediumviscosi0es,inheavydutyservicesSealchamberdesignedforallAPI682mechanicalsealconfigura0on.Possibilitytoinstallawiderangeofflushingandorquelchingpipes.Customdesignforbearingshousingincludingcooling,deflectors,bearingprotectors,monitoringsensorsetc.

Performancedata

Workingtemperature upto300°cViscosityrange upto15000cstInletpressure upto10BarDifferen0alpressure upto40BarSpeed upto3500rpm

Bearing protector or V seals

Rigid shaft rotors, made in one piece

Renevable liner at pump casing, with several materials selection

Flanged or cartdridge mechanical seals

API 520Build in satety valve

Reinforce d support housing also in carbon steel

Various bearing lubesystems

Fully customized gearbox with various special devices, up to separate oil mist external pumps, moved by main shaft rotor

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GeneralInforma0ons

OneveryPD(posi0vedisplacementpump)itisnecessarytoinstallaBy-passvalvetocontrolthatdeliverpressuredonotreachthemaximumallowableworkingpressureforpumpcasinganddeliverybrachpipes.

The2Opumpscanbesuppliedwithanintegralpressurereliefvalve.

ItispossiblealsoinstallPRV,pressurereliefvalve(namedalsoby-passvalve)directlyonpumpcasingthroughtapressurereliefconnec0onflange.

Otherconfigura0onsareavailableaccordingtoclientspecifica0onuptoAPI676withAPI520PRVexternalvalve.

REMARKS

Thepressurereliefvalveisnotforeseenasaflowcontroldeviceandnotasasecurityprotec0onofthewholeplant.

Ifnopressurereliefvalveisinstalledonthepump,aseparateoverloadprotec0onhastobeinstalledinthepressurelineinformofaPSV(PressureSafetyValve).

WORKINGPRINCIPLE

Ifthepre-setvaluesareexceededthevalveli[sfromitsseatandthefluidpassesbackintothepumpsuc0onside.

SETTING

Theopeningpressurecanbeadjustedbyresejngthevalvewiththeadjus0ngscrew.

800 Valvecasing801 Valve802 Spring803 Gasket805 Valvecover806 Gasket807 Screw808 Washer810 Springpusher811 Gasket812 Screw,regula0ng820 Valvespacer821 Gasket822 Screw823 Washer

Easyregula0onHeavydutydesignsuitableforawiderangeofsejngpressure

Fullyenclosed,topreventanyleackage

Spring

Balancigdevicesotohavehighrangewithcompactdesign

Dampingpiston,forquiteopeningclosingcycles

Valvesetdesignedfora100%capacity

www.seventech.it e-mail Italia: office@seventech.it Firenze Italia: Bucharest Romania:e-mail Romania: eurotehnic@micso.net Via Benedetto Dei 5, int 8 B-dul Camil Ressu nr.15 Tel: + 39 055 4369030 Firenze 50125 Bucuresti Sector 3 Romania