Positive Displacement Pumps

Cover Story

32 www.aiche.org/cep December 2007 CEP

Several standards (1–3) address the testing of pumps,primarily at the pump manufacturer’s test facilities.Such tests are accurate, repeatable and reliable, but

are difficult to duplicate in the field, where access to thenecessary specialized test instrumentation is often limited.

While previous AIChE field-testing procedures (4, 5)bridged the gap between the (more-accurate) pump manu-facturer test facilities and field testing methods, they applyto Newtonian liquids only. Since the first version was pub-lished in 1968, many new chemicals have been introducedby the rapidly expanding process industries. Sometimes thepumpage is not liquid, but rather a fluid in a more generalsense, such as paper pulp, slurries, waste sludge and adhe-sives — which, at least based on appearance, do not resem-ble a liquid. Non-Newtonian fluids are no longer an excep-tion that can be ignored, and pump-testing procedures mustbe applicable to such materials.

Key terminologyPositive-displacement pump. The term “pump” typically

refers to the equipment from flange to flange, i.e., betweenthe suction and discharge flanges, while the term “pump sys-tem” includes the motor, coupling, baseplate, tanks, connect-

ing piping and controls. A positive-displacement (PD) pumpcan be thought of as a flow generator, whereas a centrifugalpump can be considered a pressure (or head) generator.

Flow. The ideal flow disregards slip (i.e., the portion offlow that “slips” back through the internal clearances fromthe discharge side to suction, driven by the differential pres-sure across the pump). The net flow is what actually leavesthe pump exit into the discharge pipe. Another term oftenused interchangeably with flow is capacity.

Pressure. Relevant pump pressures include the discharge(pd), suction (ps) and differential (∆p) pressures. It is impor-tant to specify gage (psig), absolute (psia) or differential(psid) pressure; mistakes are common, especially for suc-tion vacuum. The actual available suction pressure must begreater than the minimum required suction pressure (MRSP,or ps,min) to avoid adverse effects on pump operation, suchas flow loss, cavitation, noise, vibration, etc.

Net positive inlet pressure (NPIP). NPIP is analogous tonet positive suction head (NPSH) in centrifugal pumps. Inletconditions for PD pumps are traditionally defined in pres-sure terms, rather than in head terms. NPSH, given in ft (orm) of liquid, is basically the pump inlet head minus the headequivalent to the vapor pressure of the pumped fluid. Sincedensity has already been used to convert pressure terms intohead, NPSHR (required NPSH) is not a function of density(or specific gravity), but depends on the centrifugal pump’sinlet geometry and rotating speed (approximately as a squareof speed [in rpm]).

NPIP, on the other hand, is the pump inlet pressure minusthe fluid vapor pressures. PD pumps typically operate in sys-

Here’s how to evaluate rotary pumps — gear, lobe, vane and multiple-screw designs —

regardless of whether the material being handledis a Newtonian or non-Newtonian fluid.

AICHE’s Equipment TestingProcedures Committee*Positive Displacement PumpsProcedure Subcommittee

Assess the Performanceof Positive-Displacement

Pumps

* The authors of the book from which this article is excerpted are: Lev Nelik, Pumping Machinery Co., and Luis F. Rizo, SABIC InnovativePlastics. Contributing to the Procedure were: Gordon Kirk, Univ. ofVirginia; Gary Lent, Wilden Pumps; Alan Wild, Moyno IndustrialProducts; Les Warren, Cat Pumps; John Joseph, Amoco; Jim Brennan,IMO Pump; John Purcell, Roper Pump; and Jim Netzel, John Crane. The members of the ETPC who coordinated the Procedure were: PrashantAgrawal, Kellogg Brown and Root; S. Dennis Fegan, Hermetic Pumps,Inc.; and Robert J. Hart, du Pont (retired).

CEP December 2007 www.aiche.org/cep 33

tems with low inlet velocities, and in these cases, the veloci-ty head portion (dynamic head) has generally been ignored.

NPIPR (required NPIP) is the difference between theinlet pressure and the vapor pressure (corrected to the cen-terline of the pump inlet port) necessary for the pump tooperate without a reduction in flow. The Hydraulic Institutedefines the minimum required pressure (or equivalentNPIPR) as the pressure where 5% of the flow reductionoccurs due to cavitation.

For PD pumps, an increase in the available NPIP(NPIPA) has no effect on volumetric efficiency, as long asNPIPA is greater than NPIPR. Low values of NPIPA mayresult not only in flow reduction, but also in significantpressure spikes, vibrations, noise and possible damage tothe pump.

Power. The gross power delivered by the driver to thepump is the brake horsepower (BHP), while the net powerdelivered to the fluid by the pump is the hydraulic (or fluid)horsepower (FHP). The difference between the brake andhydraulic power is due to internal mechanical and volumet-ric losses in the pump.

Efficiency. Historically, overall pump efficiency (η) hasnot been as widely used in connection with PD pumps asfor centrifugal pumps. Instead, a volumetric efficiency(ηvol) is more commonly used to compare different designsand applications.

PD pumps are, inherently, approximately constant-flowmachines with regard to differential pressure. In theory, aconstant volume of fluid is displaced (hence the name) withevery rotation, stroke or cycle. However, because of theinternal clearances, a certain amount of fluid slips backfrom the discharge side to suction. This slip depends on thelateral and radial clearances and on the overall differentialpressure that drives the slip. The higher the viscosity of thefluid, the more it resists the slip.

The net actual flow is the difference between the ideal(theoretical) flow and slip:

Qa = Q0 – Qslip (1)

which can be expressed in terms of volumetric efficiency:

The overall efficiency (often called mechanical efficiencyin PD pumps) is the ratio of useful hydraulic power trans-mitted to the fluid exiting the pump to total power absorbedby the pump:

η = FHP/BHP (3)

Viscosity. Viscosity is the property that characterizes afluid’s ability to resist motion. Dynamic viscosity (µ) is theratio of the fluid’s shear stress to the associated strain rate.Kinematic viscosity (ν) is equal to the dynamic viscositydivided by the specific gravity.

Viscosity has a major influence on pump operation.Pump power goes up with viscosity to overcome the inter-nal hydraulic viscous drag. Suction conditions become moredemanding with increased viscosity, reflecting the ability ofthe fluid to get to the pump suction port and fill its displace-ment mechanism (gears, screws, etc.).

Drive shaft speed. This term has become synonymous

Nomenclature

BHP = pump input power or brake horsepower, hp FHP = fluid, or hydraulic, horsepower, hpI = current, ampspd = discharge pressure, usually in gage units, psigps = suction pressure, usually in absolute units, psia ps,min = minimum required suction pressure (MRSP), psia∆p = differential pressure, psi or psid P = power, kWPF = motor power factor Q = flow through the pump, gal/minQa = actual net flow, gal/minQ0 = theoretical flow, disregarding slip, gal/minQslip = slip flow, gal/minRPM = pump drive-shaft rotational speed, rev/min V = voltage, V

Greek Lettersη = overall efficiency ηvol = volumetric efficiencyηmotor = motor efficiency µ = dynamic viscosity, cPν = kinematic viscosity, cSt

For More Information

This article is based on the new book,“Positive Displacement Pumps: A Guideto Performance Evaluation,” 1st edition,published by AIChE and prepared by theAIChE Equipment Testing ProceduresCommittee (ETPC). The book isdesigned to provide pump users withsimple, easy to read and understandprocedures that take into account the

imperfect realities of actual fields conditions. In addition torotary pumps, the book also covers progressive cavity, air-operated diaphragm and reciprocating positive-displacementpumps, as well as auxiliaries such as seals, bearings, rotorsand piping, plus installation. The book (ISBN 978-0-470-18097-6) is available from Wiley (www.wiley.com); the AIChEmember price is $32.00 ($39.95 nonmembers).

ηvolslipQ Q

Q=

−( )0

0

2


with RPM, the speed in revolutions per minute. In the1980s, it became common to use smaller, faster-running,pumps rather than larger, slower-running pumps, for obvi-ous cost reasons. However, with speed came trouble, asmany maintenance and reliability plant personnel discov-ered. A faster-running pump requires more suction pressure,and also wears out disproportionately faster. Iit is importantto consider not only the first cost, but also wear, suctionrequirements, vibration, etc., to strike a balance betweenspeed and reliability for a given set of flow requirements.

Types of PD pumps The two major classes of PD pumps are rotary and recip-

rocating. The majority of industrial applications are handledby the following types of pumps:

• rotary (gear, lobe, screw and vane)• progressive cavity• diaphragm• piston/plunger.This article covers the various rotary pumps. Testing pro-

cedures for the other types of PD pumps can be found in“Positive Displacement Pumps: A Guide to PerformanceEvaluation” (box, p. 33).

Gear pumps (Figure 1) may be of the external or internaldesign. Internal designs may have a crescent between gears.Fluid entering the pump fills the cavities between the gearteeth and the casing. The fluid is then moved circumfer-entially to the outlet port, and from there it is discharged.Radial hydraulic forces are unbalanced, and bearings orbushings are required to support the rotors. Since the gearstouch, the materials of construction should be dissimilar,especially for low-viscosity or poorly lubricated applica-tions. For example, a stainless-steel drive gear, if runningagainst a stainless idler gear, will tend to gall and so shouldnot be used. Typically, a stainless-steel drive gear is runagainst a nonmetallic (e.g., Teflon) idler gear.

Lobe pumps (Figure 2) are similar to gear pumps, exceptthat the lobes are not in contact, and a timing mechanism isused to transfer the rotation of the drive rotor to the idler.The number of lobes varies between one and five.

Screw pumps (Figure 3) usually have a two-screw timeddesign or a three-screw untimed design. Entering fluid fillsthe cavities between the screws and the casing or liner. Thefluid is moved axially to the outlet port, then discharged.Radial forces are unbalanced in the two-screw pump, butare balanced in the three-screw design.

The Hydraulic Institute classifies progressive cavitypumps as a single-screw design variation. However, there ismuch more similarity between the two- and three-screwdesigns than between either of those and a progressive cavi-ty design. For this reason, progressive cavity pumps are

Cover Story

� Figure 2. Lobe pump.

� Figure 1. External gear pump (top) and internal gear pump (bottom).


treated separately in the procedure, and due to space limita-tions are not covered in this article.

Vane pumps (Figure 4) employ stationary or rotatingvanes in the form of blades, buckets, rollers or slippers,which cooperate with a cam action to allow liquid to fill thecavity between the vane and the casing liner. The fluid ismoved circumferentially to the outlet port and discharged.Radial hydraulic forces may be balanced or unbalanced.Some designs provide variable flow by varying the camaction eccentricity. (Figure 4 illustrates a vane-in-rotor, con-stant-displacement, unbalanced vane pump.)

Testing rotary pumpsThe objective of a field test is to measure the perform-

ance of the pump under a known set of conditions. The per-formance of a pump may be defined by a group of six inter-related variables: flow through the pump (Q), power input(BHP), drive shaft speed (RPM), pressure at the pump’s suction port (ps), pressure at the pump’s discharge port (pd),and the kinematic viscosity of the liquid being pumped (ν).Usually, flow and power are considered the dependent vari-ables, while the others are considered independent variables.

The first step in any field test is to decide which vari-ables will be set and which will be measured as the results.When the test is performed in the field, some of the vari-ables will be difficult, or impossible, to change from thenormal values that are determined by the system in whichthe pump is installed. For example, a constant-speed motorwithout variable-speed control cannot operate at differentspeeds for the test; in this case, shaft speed would be anindependent (set) variable instead of measured.

All applicable plant safety rules should be reviewed andfollowed whenever attempting to test any rotating equip-ment. In some cases, it may be advisable to complete aplant safety review prior to testing. Finally, make sure theoperating team at the moment of the test is, at a minimum,aware of your plans and is in communication with you.

Each independent and dependent variable should havean instrument dedicated to recording its quantity duringthe test. Even variables that are supposed to be fixed, suchas the speed of a fixed-speed electric motor, should berecorded during the test to ensure that no unknown influ-ences are introduced. For example, motor speed tends todecrease as the motor load increases, and this should beobserved and recorded.

Instruments and methods of measurementTemperature. In the field, fluid temperature and the

pump skin temperature are determined to make sure theyare not excessive and thus affecting internal clearances.For certain types of pumps (especially for progressive

cavity pumps), the internal clearances change dramaticallywith temperature, affecting slip, mechanical friction, effi-ciency and pump life.

Fluid viscosity over a range of temperatures. The sim-plest way to get an idea of the viscosity during a pump testis to measure the liquid temperature, then find the viscosityfrom a chart of temperature vs. viscosity for the test liquid.Such charts are available for many liquids in referencebooks or from the manufacturer of the liquid.

� Figure 4. Vane pump.

� Figure 3. Multiple-screw pumps can have two screws (top) or threescrews (one around the shaft, one above and one below, bottom).


If no chart is available, a test with a viscometer at several different temperatures will allow you to create sucha chart. The thermometer or thermocouple used to measurethe temperature should be accurate to within 5% at the test temperature.

If the fluid to be pumped is Newtonian (i.e., it has a vis-cosity that is constant with changing shear rate), it is accept-able to test a range of viscosities by using several liquidsthat have different viscosities at the same temperature. Thisis often easier than heating or cooling a single fluid toobtain a range of viscosities. PD pumps are not very sensi-tive to changes in liquid density or specific gravity, so oneliquid can substitute for another in the test.

This must not be done, however, if the liquid is non-Newtonian (thixotropic or dilatant). If a pump is intended tooperate on a non-Newtonian liquid, the test should only bedone using that liquid. Dilatant liquids (which increase inviscosity as shear rate increases) are especially tricky,because a test on a Newtonian liquid would understate thenecessary input power and in operation the pump’s drivercould be overloaded.

Two persistent problems when a viscous fluid isinvolved are (1) establishing a reasonably accurate systemcurve for the fluid to be pumped at the (2) actual viscosityof the fluid. Emphasis is placed on the actual viscosity,which typically is a function of temperature. Startup condi-tions frequently result in lower temperatures and higher vis-cosities than at operating temperatures, and, in turn, higherhorsepower than anticipated. Unless motors, pumps andrelief systems are selected appropriately, this can cause amajor delay in the startup of a new system or in conductingtests that may pass through auxiliary piping.

Pump vendors have compiled technical manuals thatgraphically establish the relationship between pressure loss,viscosity and pipe size. Calculations for precise values areoften laborious, so estimates are frequently employed. Suchmethods approximate performance and do not generate atrue bench-test performance curve.

Flow. For PD pumps, the key measured parameter isflow. Because a PD pump moves a fixed volume duringeach revolution of the drive shaft, volumetric flowrate ismost closely tied to pump performance. It is also possible tomeasure mass flow and divide by the density of the liquid.A flowmeter in line with the pump is the simplest and mostcommonly used method to measure flow.

To ensure accuracy, the flowmeters should be periodicallycleaned and calibrated. In theory, the viscosity of the meas-ured fluid must be similar to that of the calibration fluid. Inpractice, though, there can be a wide variation in viscosity(±1,000 cP), and the flow measurement error would be with-in ±2%, which is acceptable for most field tests.

Shaft speed. Since the theoretical flow of a PD pump isdirectly proportional to speed, another simple method is tomeasure the pump shaft speed in rpm, and multiply that bythe pump unit flow (gal/rev). The unit flow is constant for agiven pump and can be calculated from the pump perform-ance curve at zero differential pressure. The net (actual)flow is the difference between the theoretical (zero pressuredifferential) flow and slip. Slip can be obtained from thepump curve at a given differential pressure and fluid viscos-ity. In practice, for high-viscosity fluids (> 100 cP) and/orlow differential pressures (< 20 psi), the slip can be neglect-ed and the net flow simply calculated as the measured speedtimes the unit flow from the curve.

It is a good practice to conduct a field test of a pumpsoon after it has been installed, in order to generate a base-line field-specific curve for the future test comparisons.

Many types of tachometers can be used on either thepump or motor shaft, as long as a device that maintains aconstant speed ratio between the two shafts is used to con-nect the shafts. If a device that varies the speed ratiobetween the shafts, such as an eddy current drive, is used,the tachometer must only be used on the pump shaft.

Suction and discharge pressures. A common mistake isto assume the pressure at the pump inlet flange from theknown pressure (such as tank level) and adjust by calculat-ing the losses (or assuming the losses are negligible). Thisapproach is particularly wrong for the suction pressure,because collapsed filters, debris, solids or other obstructionscan render the pressure estimates invalid. The only reliableway to determine pressure is to install gages to measure thepressure in the suction and discharge pipes as close to thepump flanges as possible.

Pressure gages (or transducers) should be accurate towithin 5% at the test pressures, and the test pressure shouldbe between 20% and 80% of a gage’s range. The suctionand discharge pressure gages usually have different pressureranges. Suction pressure is typically recorded in absoluteunits (psia), discharge pressure in gage units (psig).

Power and efficiency. The most practical way to measurepump input power is to measure the electric current (I) andvoltage (V) of the motor and then calculate the availableshaft power (BHP):

Cover Story

for single-phase motors:

PI V motor=

× ×η1 000,

44a

for 3-phase motors:

( )

=× × × ×

PI V motor1 732. η PPF

1 000, 4b( )


The power factor (PF) and motor efficiency (ηmotor) cannormally be obtained from the motor manufacturer, at leastfor full-load conditions. Both vary widely from motor tomotor and with changes in load on the motor.

If power factor and efficiency cannot be accurately deter-mined at the motor’s operating conditions, it may not bepossible to accurately determine the pump’s input power. Inthat case, the only test for input power may be to check thatthe motor current is not above the nameplate rated currentat pump operating conditions.

If the system has a gear reducer or another device thatabsorbs motor output power coupled between the motorand pump, some estimate of its power losses must befound. This is often available from the manufacturer of thedevice. If the pump and motor are directly coupled, themotor output power can be used as the pump input power.

In most cases, the power factor and motor efficiencyare not readily known, and obtaining the exact values isimpractical. However, as an approximation, the efficiencyof the electric motor can be assumed to be 95%, and thepower factor can also be assumed to be 0.95, so theirproduct is approximately 0.90. As long as the performancedoes not change over time, such an approximation is valid.Any approximations used should be reviewed and con-firmed, since a motor efficiency of 95% and power factorof 0.95 are high estimates and ususally apply to motors of200 hp and above.

The hydraulic (net) fluid power is:

The current used to calculate power must be read at theactual operating differential pressure. The overall pump effi-ciency is then obtained from Eq. 3 (η = FHP/BHP).

Standardized performance testThe purpose of a performance test is to generate graphs

of flowrate vs. differential (discharge minus suction) pres-sure, and input power vs. differential pressure, at a constantliquid viscosity, suction pressure and shaft speed. In addi-tion to the test equipment discussed previously, this testalso requires a valve near the outlet port of the pump thatcan be used to throttle the flow to increase the pressure atthe pump. The highest pressure during the test should notexceed 90% of the opening pressure of any relief valve inthe system or in the pump. Any restrictions in the systemdownstream of the pump should be reduced as much aspossible to reach lower pressures at the pump during thetest. Figure 5 illustrates the typical field-test setup.

Estimate the range of discharge pressures to be tested,and divide the maximum expected differential pressure by

five (i.e., a six-point test). The result is the amount toincrease the discharge pressure for each subsequent test point.

To begin, operate the pump with the throttling valveopen, and record the values of all six variables on aPerformance Test Report Form such as the one at the end ofthis article. Close the discharge throttling valve slowly andrecord all six variables. Continue increasing the pressureincrementally and recording the six variables. Plot the datain the form of graphs, as shown in Figure 6.

FHPp Q

=×

+ ( )∆ 0

1 714,viscous losses 6

� Figure 6. Plot the recorded input power and flowrate at variouspressure drops.

120

100

80

60

40

20

0∆p, psi

Flo

wra

te, g

al/m

in

120

100

80

60

40

20

0∆p, psi

Inpu

t Pow

er (

BH

P),

hp

� Figure 5. Typical set-up for a pump performance field test.

DischargeVessel

AtmosphericVent

Flow-meter

GateValve

Tank Overflow

ReliefValve

Pump

MotorTachometer

DischargePressure

Gage

SuctionPressure

Gage

Flow Indicator

SuctionTank


Standardized MRSP testThis test determines the effect of changing suction pres-

sure on the performance of the pump. Below a certain pres-sure, the flow out of the pump will drop dramatically.Above this pressure, the flow asymptotically approaches thetheoretical flow of the pump. The suction pressure thatcauses the flow to drop 5% below this asymptote is consid-ered to be the pump’s minimum required suction pressure(MRSP or ps,min). This test requires a throttling valve in thesuction piping near the pump, as well as another valve onthe discharge side. Figure 7 shows this test setup.

At the beginning of the test, all valves on the dischargeside of the pump should be open, to lower the pump’s dis-charge pressure as much as possible. The pump’s supplytank should be full or, if it is portable, raised as high abovethe pump as possible. This is to increase the pressure at thepump’s suction so that during the test, the flow will be as

close as possible to the theoretical (Q0) when the suctionvalve is open.

An abbreviated version of the performance test reportform, modified so that only suction pressure and the floware recorded, can be used. Other parameters of interest mayalso be recorded. During this test, shaft speed, dischargepressure and liquid viscosity are held constant; input powerdoes not change much, so it is usually not measured.

Operate the pump with both throttling valves open, andrecord the values of all of the variables. Start slowly closingthe suction-side throttling valve until the suction pressuredrops 2 psi below its previous value. Record the values of allthe variables again. Repeat this process using increments of 2psi in the suction pressure until the pump’s flow has droppedto 90% of what it was at the beginning of the test. Do notoperate the pump in this condition for any longer than is nec-essary to record the data, and never close the suction-sidevalve all the way while the pump is running. Plot the flow atvarious pressures in the form of a graph such as Figure 8.

If increased noise or vibrations are encountered, do notoperate beyond that point. In this case, the MRSP would bedetermined not based on a 5% flow decrease, but rather bythe mechanical and structural limitations of the pump or thesystem. Discuss these results with the pump manufacturer.If the MRSP thus determined is significantly different fromthe value in the manufacturer’s catalog, pump and/or systemtroubleshooting is advisable.

Other testsMany other tests may be performed on pumps other than

the two just described (performance and suction). The threemost common are sound pressure-level, vibration and tem-perature measurements.

Sound pressure level. Sound pressure-level measure-ments may be taken at the pump’s normal operating condi-tion, or may be made in conjunction with one of the testsdescribed earlier to create a record of the sound pressurelevels across a wide range of conditions. The microphonesfor the test should be located approximately 5 ft above thefloor or walkway nearest the pump. (All of the readings aretaken 5 ft above the floor.)

One reading should be taken at each end of the pump andmotor set, approximately 3 ft from the housing of the pumpor motor. Other readings should be taken at the pump’s inletand discharge ports and on both sides of the motor. If thepump and motor are mounted vertically, take a reading atfour positions, 90 deg. apart around the pump, 3 ft awayfrom the nearest part of the pump or motor housing.

Note that the environment around the pump, such asacoustically reflective or absorbent surfaces, can have alarge influence on the measured sound pressure value. Other

Cover Story

� Figure 8. Plot MRSP test results in terms of flowrate vs. suction pressure.

Flo

wra

te, g

al/m

in

25

20

15

10

5

0

Decreasing Suction Pressure, psi

MRSP

5% Drop in Flow

10% Pressure Drop

� Figure 7. Typical set-up for a minimum required suction pressure (MRSP) test.

DischargeVessel

AtmosphericVent

Flow-meter

ThrottlingValve

Tank Overflow

ReliefValve

Pump

Motor

SuctionTank

Flow Indicator

ThrottlingValve

(used duringtesting for ps,min)


equipment operating nearby will also influence the soundpressure measurements.

Vibration and temperature. Vibration and temperaturemeasurements are usually taken for maintenance reasons.They can be used to predict an impending failure so theproblem can be corrected before it occurs. To do this, it isvery important to take baseline measurements before anyproblems occur. Then changes in these quantities over timecan signal a potential problem.

Vibration and temperature measurements are typicallytaken at the pump’s normal operating condition. The keyparts of the pump that affect its reliability must be deter-mined, and the measurements taken as near as possible tothose components. Measurements are usually taken on thesurface of the pump housing; instrumentation can be putinside the pump before installation to monitor particularlycritical components. The most commonly monitored com-ponents are bearings, rotors and shaft seals.

The Time Trending of Basic Pump Parameters formbelow can be used to record pump parameter trends overtime to detect the changes. However, the basic parameters,such as speed, operating pressure, pumped liquid, etc., mustremain the same in order to obtain a valid comparison of theparameters that are truly changing with time.

Literature Cited1. The Hydraulic Institute, “Rotary Pump Standards,”

Publication No. ANSI/HI 3.1–3.5, 3.6, 4.1–4.6, TheHydraulic Institute, Parsippany, NJ, www.pumps.org (2000).

2. American Petroleum Institute, “API 610 Standard forCentrifugal Pumps, Revision 4,” ISO 13709, API,Washington, DC (Oct. 2004).

3. American Petroleum Institute, “API 676 Standard forRotary Pumps, Revision 4,” ISO 13709, API, Washington,DC (Mar. 2004).

4. American Institute of Chemical Engineers, “CentrifugalPumps (Newtonian Liquids), 3rd Edition: A Guide toPerformance Evaluation,” AIChE Equipment TestingProcedure, AIChE, New York, NY (June 2002).

5. American Institute of Chemical Engineers, “RotaryPositive Displacement Pumps (Newtownian Liquids), 2ndEdition,” AIChE Equipment Testing Procedure, AIChE, NewYork, NY (1968).

Further ReadingHeald, C. C., ed., “Cameron Hydraulic Data Book,” 19th ed.,

Flowserve Corp., Irving, TX, www.flowserve.com.Nelik, L., “Extending the Life of Positive Displacement Pumps,

Part 1: Gear Pumps,” Pumps and Systems, 7 (4), pp. 30–31(Apr. 1999).

Nelik, L., “10 Steps to Proper Pump to Piping Alignment,”Pumps and Systems, 13 (9), pp. 16–17, (Sept. 2005), 13 (10),pp. 20–21 (Oct. 2005), and 13 (11), p. 19 (Nov. 2005).

Stepanoff, A. J., “Centrifugal and Axial Flow Pumps: Theory,Design and Application,” 2nd ed., Krieger Publishing Co.,Melbourne, FL (1992).

TestPoint

ShaftSpeed,

rpmSuction Pressure,

DischargePressure,

psigFlowrate,

gpmViscosity,

cP

InputPower,

hp

Performance Test Report Form

psia psig∆P,gpm

LiquidTemp.,°F

#1

#2

#3

#4

#5

#6

TestDate/Time

Speed,rpm

SuctionPressure,

psia

DischargePressure,

psigFlow,gpm

Current,amp Temp.,°F Unusual

Sounds?Vibration,

in./s

RecordedBy

(initials)

Time Trending of Basic Pump Parameters

Positive Displacement Pumps

Documents

Transcript of Positive Displacement Pumps