Functions of a PumpTransfer fuid between two points.Produce required fow rate.Produce required pressure. Pump - FactsPump changes both velocity and pressure of the fuid.Pump only adds to the system energy.Power supplied to the pump is to transfer fuid at specifed fow rate and pressure by overcoming resistance in the pump and the system.A pump does not create pressure it only provides fow. Pressure is !ust an indication of the amount of resistance to the fow. Viscosity of the fluid pumped must be within the range specified in the pump design.Reciprocating Displacement pumps can handle any required viscosity.Rotary Positive Displacement Pumps ( Common- ear and !crew " are used for intermediate range of viscosities.Centrifugal Pumps are used for #edium to $ow range of viscosities. %nboard ships& permission should be obtained before any fluids are moved& which might affect the stability of the ship.Pumps and "iscosity of Fluid#andled. $entrifugal Pump %&otodynamic' Centrifugal pump distinguished from Positive displacement pump ------ &equirement of relative velocity between the fuid and the impeller. (haped casing or diverging no))le converts *inetic energy into pressure energy. +iquid in the impeller and casing essential for pump operation. $entrifugal Pump.The energy changes occur in a centrifugal pump by virtue of two main parts of the pump.The ,mpeller - The rotating part that converts driverenergy into *inetic energy.The volute or .i/user - The stationary part that converts the *inetic energy into pressure energy.The process liquid enters the suction no))le and then into the eye of the impeller. ,mpeller spins the liquid sitting in the cavities between the vanes outwards and provides centrifugal acceleration. As liquid leaves the eye of the impeller a low pressure area is created causing more liquid to fow towards the inlet. 0ecause the impeller blades are curved the fuid is pushed in a tangential and radial direction by the centrifugal forces.$entrifugal Pump- Theory The process liquid enters the suction no))le and then into the eye of the impeller. ,mpeller spins the liquid sitting in the cavities between the vanes outwards and provides centrifugal acceleration. As liquid leaves the eye of the impeller a low pressure area is created causing more liquid to fow towards the inlet. 0ecause the impeller blades are curved the fuid is pushed in a tangential and radial direction by the centrifugal forces.$entrifugal Pump- Theory $entrifugal Pump - TheoryThe amount of energy given to the liquid is proportional to the velocity at the edge or vane tip of the impeller. The faster the impeller revolves or bigger the impeller is, then higher will be the velocity of the liquid at the vane tip and greater the energy imparted to the liquid. $entrifugal Pump - Theory.The kinetic energy of a liquid coming out of an impeller is harnessed by creating a resistance to the fow. The rst resistance is created by pump volute casing, which catches the liquid and slows it down. !n the discharge no""le, the liquid further decelerates and its velocity is converted to pressure. $entrifugal Pump - #eadThe pressure at any point in a liquid can be thought of as being caused by a vertical column of the liquid due to its weight. The height of this column is called the static head and is e#pressed in terms of meters of liquid. $ead is a measurement of height of a liquid column that a pump could create from kinetic energy imparted to the liquid. !magine a pipe shooting a %et of water straight up into the air, the height the water goes up would be the head. $entrifugal Pump - "apour Pressure&apor pressure is the pressure at which a liquid and its vapor co-e#ist in equilibrium, at a given temperature. &apori"ation begins when the vapor pressure of the liquid at the operating temperature equals the e#ternal system pressure, which in an open system always equal to the atmospheric pressure. 'ny decrease in e#ternal pressure or rise in operating temperature can induce vapori"ation and the pump stops pumping. $entrifugal Pump - "elocity#ead"elocity #ead refers to the energy of a liquid as a result of its motion at some velocity1 " 1. ,t is the equivalent head in meters through which the water would have to fall to acquire the same velocity or the head necessary to accelerate the water."elocity head is insignifcant in most high head systems but it can be large in low head systems. Factors A/ecting (uction +ift'emperature and volatility of the fluidPressure e(erted on the free side of the liquid.)riction $osses at entrances& bends and pipes in the suction system. Priming of $entrifugal Pump.Priming is the process of removing Air2"apour and flling the suction piping impeller and pump casing with the fuid.()T$*+, *- P.!(!/0 +iquid ring air-pump. 3!ector. &eciprocating Pump. - 4bsolete. ,mpeller of $entrifugal PumpTypes of ,mpellers 5ith &espect to Flow.&adial fow.A6ial fow.7i6ed fow.Types of ,mpellers 5ith &espect to $onstruction. o *pen %with partial shrouds for strength. - - For abrasive liquids with suspended solids.o ,emi-*pen - - For viscous liquids.o )nclosed - - For clear liquids. ,mpellers 4pen (emi-open and enclosed ,mpellers 4pen (emi-open 3nclosed (ingle and .ouble 3ntry ,mpellers Types of $entrifugal Pumps 5ith &espect to the $onstruction of the $asing. &olute +i1user .egenerative"olute $asing ,t is li*e a curved funnel increasing in area to the discharge port which converts velocity energy into pressure energy. Also it helps to balance the hydraulic pressure on the shaft of the pump- occurs at the recommended capacity. &unning at lower capacity can put lateral stress on pump shaft increase wear-and-tear on the seals bearings and on the shaft itself.$entrifugal Pump .ouble "olute Pump .i/user or $ircular $asing,t has stationary di/usion vanes surrounding the impeller periphery that convert velocity energy into pressure energy. $onventionally the di/users are applied to multistage pumps. .i/user $asing &egenerative%turbine Pump' The impeller , which has very tight a#ial clearance and uses pump channel rings. 2iquid entering the channel from the inlet is picked up immediately by the vanes on both sides of the impeller and pumped through the channel by shearing action. The process is repeated over and over with each pass imparting more energy until the liquid is discharged. Turbine Pump Turbine Pump A6ially2&adially (plit $asing 8land Pac*ing- (tu9ng 0o6 (tu9ng 0o6 ,mpeller wear rings $entrifugal Pump #ori)ontal Two-stage $: Pump Two-(tage "ertical $ : Pump $avitation $entrifugal Pump - 4perational (ummaryoT$.)) !/+!C'T!*/, !- ' P3(P !, C'&!T'T!/0o/oise.o-luctuating discharge pressure and fow.o-luctuating pump motor current.(teps to (top cavitation of a Pump !ncrease pressure at the suction of the pump. .educe the temperature of the liquid being pumped. .educe head losses in the suction piping. .educe the fow rate through the pump. .educe the speed of the pump impeller. 3/ects of cavitation.o +egraded pump performance.o (etal gets corroded seen as small pittings.o 'udiable rattling or crackling sounds which can reach a pitch of dangerous vibrations.o +amage to pump impeller, bearings, wear rings and seals. Pump 4peration - Facts To avoid pump cavitaion ;P(# available must be greater than ;P(# required. ;P(# available is the di/erence between the pump suction pressure and the saturation pressure of the liquid being pumped. $avitation is the process of the formation and subsequent collapse of vapor bubbles in a pump. 8as binding of a centrifugal pump is a condition where the pump casing is flled with gases or vapors to the point where the impeller is no longer able to contact enough fuid to function correctly.Pump 4peration - Facts< ,hut o1 head is the ma#imum head that can bedeveloped by a centrifugal pump operating at a set speed.< Pump run out is the ma#imum fow that can be developed by a centrifugal pump without damaging the pump.< The greater the head against which a pump operates, the lower the fow rate through the pump.< Centrifugal pumps are protected from run-out by placing orice or throttle valve immediately downstream of the pump discharge and through proper piping system design.< The centrifugal pump can be protected from dead-heading by providing a recirculation from the pump discharge back to the supply source of the pump.$entrifugal Pump 4peration -Facts .ischarge Pressure - 7inimum throughput when head is ma6imum. Power - 7inimum power consumed when no fow and the discharge head is at the highest. +osses - =' (hoc* and eddy losses caused by impeller blade thic*ness and other mechanical considerations. >' Frictional losses due to fuid contact with the pump casing etc.?' ,nlet and ,mpact losses. $haracteristics of "ariable (peed $entrifugal Pump. #ead varies as the square of the speed. $apacity varies directly as the speed. Power varies as cube of the speed. $haracteristics of $onstant (peed $entrifugal Pump #ead varies as square of the diameter. $apacity varies as the diameter. Power varies as the cube of the diameter. $oupling $oupling Alignment Alignment Alignment Alignment $entrifugal P2P 4@hauling4asic Types of Parts:-.otating Parts - ,mpeller (haft wearing rings shaft sleeves bearings 7echanical seal etc,tationary Parts - $asing bearing housing suction and discharge fanges pac*ing lea*-o/ tubing base plate etc$ent: P2P 4@hauling- ,mpeller ,nspect eyes vanes shroudswearing rings passages hubs and other parts. $orrosion $avitation and 3rosion are generally accompanied by a wasting away of the impeller and vane surfaces. 5here attac* is severe the thinned sections may have holes through them or may warp and defect. 0adly worn or corroded impellers may vibrate e6cessively. 0alancing is required. $hec* on a lathe. 7etal to be removed on heavier side. ,f required ta*e a cut on the shroud deepest at the rim. $ompare with a spare ,mpeller. $ent: P2P 4@hauling- shaft Check for bent shaft5 out of square, dirty or burred impeller end of the shaft or spacer sleeve. Check 6 2ock nut washer is burred or the faces of it and other parts are not parallel. Check for bent shaft by means of a dial gauge, swinging between lathe or other centers. Tap and check impeller shaft key to see it is tight. Twist of shaft under load, )#pansion or corrosion will progressively loosen the impeller.. $ent:P2P 4@hauling- wear ring 5ear rings are installed in the casing or impeller or both. ,t will run as bearings while lubricated by the fuid being pumped. $hec* the clearances to ma*e sure it is within limits. ,f not replace the wear rings. 5ear rings are usually made out of non-galling materials. 3A:0ron)e with dissimilar bron)e. 7a*e sure that the wear rings are ftted correctly. $ent:P2P- 4@hauling- 0earings< 0all bearings etc. - Beep all rolling-contact bearings clean at all times. Cse clean tools and clean surroundings. Cse clean solvents and fushing oils. $lean inside of housing before replacing the bearings. ,nstall new bearings as removed from their pac*age without washing. To remove a bearing press or pull only on the rings which is tight pressD pull straight. < (leeve20ush bearings - $hec* clearances if over the limit value replace the same.$ent:P2P4@hauling-7echanicalseal.o ;ormally only faces require repair.o ,f stationary face is slightly scored lap it on a lapping plate. ,f dirt or scale is imbedded ta*e a cut in lathe to remove material to below the imbedded element.o &emove spring assembly for cleaning and inspection.o For replacement choose the correct type.o 8ood Practice - To rotate pumps equipped with mechanical seals once a day when stopped. $ent:P2P 4@hauling (haft (leeve 8land Pac*ings. $hec* for worn shaft and shaft sleeve. 7achine it and use it if groove2wear is not deep. 4therwise replace the sleeve. $hec* and replace the sealing ring of the sleeve. &emove and replace all gland pac*ings with correct type and si)e pac*ings. $lean the housing thoroughly before inserting the pac*ings. .o not over-tight the gland. $hec* by rotating the shaft by hand. $ent:p2p4@hauling (tationary Parts Casing7- )#amine for corrosion or erosion. (ay be repaired by welding, bra"ing and machining or metal spraying5 depending on the material. 0askets7- To be renewed with correct thickness and type. ,urface of gasket seating has to be clean. +o not use oil, grease or varnish. 3se proper tightening sequence for casing bolts and studs. 4edplate and -oundation7- 8eep clean, Check for irregularity, keep drain lines clear. Check foundation bolts for tightness. Piping7- Check for leaks, damaged insulation, water hammer, defective valves, improper alignment etc. A6ial Pump A6ial Pump Cnder low head % >.E to F.> m' #igh throughput %>GHH- IEHH m?2hr '- conditions required by main condensers in steam ships. Pump is reversible. Pump will idle and o/er little resistance when fow is induced through it by e6ternal means. ,deal for condenser circulating duties in steam ships and for heeling and trimming duties.A6ial Flow Pump A screw propeller by causing and a6ial acceleration of liquid within its blades create a pressure increase. ,ncidental rotation imparted to the liquid is converted to a6ial movement by suitably shaped outlet guide vanes. Throttling of the discharge valve causes a rise in pressure and power. 5ith discharge valve closed and )ero discharge the head will be three times and power doubled. $auses water hammer. A6ial Flow Pump 7i6ed Flow Pump Positive .isplacement Pumps. +iquid or gas displaced from suction to discharge by mechanical variation of the volume of a chamber or chambers.centrifugalpumps==.gifcentrifugalpumps==.gif Types of Positive .isplacement Pumps. &3$,P&4$AT,;8 - Plunger or Piston mechanically reciprocated. &4TA&J - +iquid forced through the pump cylinder or casing by means of screws or gears etc. /ecessity of .elief &alve in Positive +isplacement Pumps. Positive +isplacement Pumps will produce increasing pressure until rupture or drive failure. $a"ardous material discharge from .elief &alve must be contained within the pumping system. Types of Positive displacement Pumps. .eciprocating piston pump. 0ear type rotary pump. 2obe type rotary pump. ,crew type rotary pump. (oving vane type pump. +iaphragm pump. -le#ible vane pump.

Types of P . Pumps Piston Pump Piston Pump &eciprocating Piston Pump Plunger Pump "arious $hec* "2"s A6ial Piston Pump A6ial Piston Pump (wash Plate Pump A6ial Piston Pump 5obble Pump &adial Piston Pump &adial Piston Pump +obe Pump 2obe Pump +obe Pump Two or more rotors cut with two, three or more lobes on each rotor. .otors are synchroni"ed for positive rotation by e#ternal gears. 2iquid delivered in a small number of large quantities. $ence fow is not as constant as from gear pumps.+obe Pump- Type > ,nner and outer elements rotate in a renewable liner ftted in the pump body. The inner rotor is eccentric to the outer and is ftted to a shaft located by bearings in the pump covers. Pump types are defned by the number of lobes and recesses: Three-Four (even-3ight etc. ;ormal 7a6 Pr >= bar $ap KHH t2hr Three-Four typesL(low speeds high viscosity fuids (even-3ight typesL#igher speeds and lower viscosity fuids. 8ear Pump 8ear Pump 8ear Pump,nternal 8ear Pump $rescent ,nternal 8ear Pump $rescent ,nternal 8ear Pump $lassifed by the type of gears used- (pur #elical #erringbone etc $ommonly used on board for handling small quantities of Fuel oil +ub oil etc (hafts running on bushes or bearings usually lubricated by oil being pumped. 8ear bac*lashH.>-H.Emm %amount by which a tooth space e6ceeds the thic*ness of the engaging'- ,f no bac*lash trapped oil between two teeth impedes gear rotation +oss in power additional load on bearings spreading of gears and heating of the liquid. 8ears &eciprocating Pump =. .iaphragm Pump .iaphragm Pump "ane Pump (lide "ane Pump "ane Pump Fle6ible ,mpeller Pump%fe6ible"ane Pump' Fle6ible ,mpeller Pumpo (elf priming can be mounted above or below the source of the fuid.o (imple construction- ,ne6pensive.o 8entle pumping action - e/ectively handles thin viscous and particle-laden fuids.o Typical applications- +ow rate low pressure high viscosity uses. Temperature range- H to IH o$.o ,mpeller- Fle6ible synthetic rubber #ousing- (tainless (teel+obe Pump (ingle (crew Pump(ingle (crew Pump %3ccentric #elical &otor Pump (na*e P2P' Csed for smooth fow low capacity applications. .uring rotation rotor %stainless steel' tightens against the stator %natural or synthetic rubber' with double internal screw threads and enclosed fuid is displaced a6ially.All cross sections of rotor are circular.$enter-line of pump moves radially during rotation hence driven through universal !oint. .ouble (crew Pump< 7ounted hori)ontally or vertically.< 3ach screw shaft has a right and left hand screw which ensures hydraulic balance.< 7etal contact avoided by timing gears.< +iquid drawn and pumped inwards to the discharge located at rotor mid-length. < .ischarge is without pulsations.< For non-corrosive liquids of reasonable lubricity usually internal bearings are used. .ouble (crew Pump For corrosive liquid with lac* of lubricity and2or high very high viscosityD outside bearings which can be independantly lubricatedare used. Pumps with inside bearings are shorter and lighted and have only one shaft seal against four in the other case. (haft seal is usually at the suction end of the pump % low pressure or vacuum '. Csually mechanical seals are cooled and lubricated by the pumped liquid. Triple (crew Pump Triple (crew Pumps Triple (crew Pump.$enter screw is driven outer screws are idle. 4uter screws are driven by fuid pressure and act as seals.5hen screws rotate their close relation to each other creates poc*ets in the helicesD these poc*ets move a6ially.These pumps wor* well at high pressure and with high viscosity fuids. Triple (crew Pump Triple (crew Pump Triple (crew Pump Triple (crew Pump (crew Pumps #igh heli6 angle screws are used for relatively high speed on small pumps. +ower heli6 angle screws are used on large pumps. (crew Pumps Are Csed--- For pumping high viscosity liquids such as oils and some liquid cargoes. For draining tan*s of high vapor pressure liquids since self priming and being able to pump liquid and vapor without loss of suction. For operation at high rotational speeds since it can be easily matched with standard motors. $ircumferential Piston Pump Positive .isplacement Pumps *ften used for small capacities and when needed to avoid churning. 'lso used for high viscosity liquids. Can control fow by regulating speed. 3sed often for high or very high pressure. 'lso as metering pumps. 9ill produce any head that is impressed on them.+irect 'cting .eciprocating pump classed as $ori"ontal or &ertical : $ or & ; ,ingle or +uple#: , or + ; ,ingle or +ouble 'cting: ,' or +' ; Positive .isplacement Pumps- $haracteristics.o 4utput is almost directly proportional to the speed.o 4utput marginally reduced at increased pressure. %(lip'o 5ill develop discharge pressure equal to the resistance to be overcome.o (elf priming.o 5ill accept high suction lifts.o $an handle large amounts of entrained gases or vapors.o $onstruction is complicated. &otary .isplacement Pumps. .ely on ne clearances between moving parts for their e