Rotary Screws Pumps
www.seventech.it
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.
www.seventech.it
Thepumpis0medtwinscrewrotarytypeanditiscomposedbyacoupleofrotoraxes,withopponentcoils,withmutualspecialoutlinethatworkinsideachambersetinthepumpcasing.Oneveryrotor,madeinonebar,twocontrastedandsynchronizedscrewsarerealizedtobalanceeveryhydraulicsthrust,andthroughexternaldevice,gearcouplewiththerotorsaresincronizedtogether.Thepumpedupfluidgoesintothepumpcasingfromtheaspira0onflangeandthendividedintwodifferentparts,a[eritisaspiredbythescrewsandpushedinaxialwaytowardthedeliveryflange.Thespecialopposedscrewsprofilecreateduringthechambersrota0onswhichconstantlypushwithoutbeatstowardthedeliverypump,inthisway,thepumpisabletotransporteverykindoffluidindependentlyfromthefluidviscosity.Thesynchronismedevice,0minggears,preventsanymetalliccontactduringrota0onandenablethepumpingofnon-lubrica0ngfluidsaswellasaggressivemedia.Thisdesignalsoallows
dryrunningandselfpriming
www.seventech.it
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.
www.seventech.it
Bearinghousing,oillubricated.Solu0onwithfullyenclosedIP65bearinghousing
Engineeredandcustomsmechanicalseals
Renevablecastedliner
Screwmachinedfromonebar,onepieceonlyandanymaterial
combina0on.Dinamicallybalanced.Possibilitytohardening
threatments.Differentscrewprofilesinfunc0onofdesidered
perfomances.
Posi0velylocked0minggearsbymeanofkeys
Easymoun0ngbearings:Itispossibleremovethemechanicalsealswithoutremovingthebearings.
Castedorweldedpumpcasingavailableinhorizontalorver0calsolu0on.Possibilitytohavehea0ngjacket.
www.seventech.it
I
L
M
H
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.
www.seventech.it
www.seventech.it
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(-)
www.seventech.it
BearingHo
using
Labirinth
Bearingprotectors
Bronzelabirinth.
Bearingprotectorsormagne0cseals,IP67,forfullyenclosedinstalla0on.
Sealrings
Standardinstalla0on,possibilitytohaveperfluoroelastomerpolymers.
Bearingarrangementsofalltypesdonotpnlyconsistofbearingsbutincludetheassociatedcomponents,suchassha[sandhousings,aswellasseals.Theperformanceofthesealisofdecisiveimportancewherelubricantcleanlinessisconcernedandthiscleanlinesshasconsiderableinfluenceonbearingandpumplife.
www.seventech.it
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
www.seventech.it
CartdridgeMechanicalSealsaccordingtoAPI682withfullyconfinedmechanicalsealchamber.APIrecommenttouseaconfinedmechanicalsealchamberbymeanofthroWlebushingwithnongallingmaterials.AllmechanicalflushingandquelchingPlanaccordingtoAPI682recomenda0on.Thepurposeofthestandardwastocaptureprovensolu0onstothemostcommonsealingapplica0onsseeninrefinerieswherewemustbeassurehighreabilityinheavydu0esservice.Nolimitsformechanicalsealflushingconfigura0on.Fullyconfinedmechanicalsealchamberassurehighreabilityalsowithmixedphasefluids.Largespacewithlongersupportsforeasymaintenance.
(A)API682cartdridgemechanicalseals
Single Single + Qelch Single + Qelch Double API 676Cartdrige
I
L
M
H
S F C A Safety
Packingseals
✔ ✔ ✔ ✔ ✔ ✔
✔ ✔
✔ ✔ ✔
✔✔
www.seventech.it
I
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
www.seventech.it
L
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
www.seventech.it
www.seventech.it
M
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
www.seventech.it
www.seventech.it
H
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
www.seventech.it
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: [email protected] Firenze Italia: Bucharest Romania:e-mail Romania: [email protected] Via Benedetto Dei 5, int 8 B-dul Camil Ressu nr.15 Tel: + 39 055 4369030 Firenze 50125 Bucuresti Sector 3 Romania