book-hydraulics pump seminar

EFFICIENT BY DESIGN

CORNELL PUMP COMPANY

&

Hydraulics Wkbk Coverv2.qxd:Hydraulics Wkbk cover.qxd 9/6/07 11:24 AM

It’s unwise to pay too much, but it’s worse to

pay too little.

When you pay too much, you lose a little

money, that’s all.

When you pay too little, you sometimes lose

everything, because the thing you bought was

incapable of doing the thing it was bought to do.

The common law of business balance

prohibits paying a little and getting a lot —

it can’t be done.

If you deal with the lowest bidder, it is well

to add something for the risk you run, and if

you do that you will have enough to pay for

something better.”

John Ruskin

“

Hydraulics Wkbk Coverv2.qxd:Hydraulics Wkbk cover.qxd 9/6/07 11:26 AM

Mounting Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3Quality Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4Terminology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6Fact Finding to Determine Pump Choice . . . . . . . . . . . . . . . . . . .13Selecting the Pump . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .18Multiple Pumps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .20Specific Speed . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .22Affinity Laws . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .23Pump-Engine Selection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .24Engine Derate Guidelines . . . . . . . . . . . . . . . . . . . . . . . . . . . . .25Average Electric Motor Life . . . . . . . . . . . . . . . . . . . . . . . . . . .26Guide to Optimum Electric Motor Life . . . . . . . . . . . . . . . . . . . .27Electric Motor Comparisons . . . . . . . . . . . . . . . . . . . . . . . . . . .28Electric Control Panel Data . . . . . . . . . . . . . . . . . . . . . . . . . . . .29Typical Auto Vacuum Prime . . . . . . . . . . . . . . . . . . . . . . . . . . .30Materials of Construction . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3 1B-10 Bearing Calculation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .33Pump Performance Curves

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .34 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .35

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .36 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .37 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .38 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .39

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .40 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .41

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .42 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .43

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .44Specification Guide – Cornell Solids Handling Pumps . . . . . . . . . .45Lubrication Instructions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .47Start-up Check List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .50Pump Troubleshooting Guide . . . . . . . . . . . . . . . . . . . . . . . . . .5 1Air Leaks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .52Packing, Wear Rings and Coupling Alignment . . . . . . . . . . . . . . . .53Pump Care . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .54

2.5 WB4 WB5 WB5 YB4 RB6 RB6 RB-Various RPM4 HH4 x 4 x 14T6 NHTA6 NHPP-Various RPM

Table of Contents

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Cornell Pump CompanyP.O. Box 6334 Portland, Oregon 97228

Phone: (503) 653-0330 Fax: (503) 653-0338

Web: www.cornellpump.com

© 2007. Cornell Pump Company. All rights reserved.


Cornell Pump Company • Portland, Oregon CORNELL

3

Mounting Configurations

Horizontal Close-Coupled (CC).Economical, compact and efficient.

Horizontal Frame (F).Driver flexibility.

Vertical Frame (VF).Driven by flexible shaft

from motor above pump.

Redi-Prime®

Run-dry, automatic dry prime andre-priming capabilities.

SAE Engine Mount (EM).Ideal for remote locations or where

electrical power is not available.Trailer or skid mounted.

Base-Coupling-Guard MountedHorizontal Frame Unit.

Can be mounted with a motor or otherdriver on a common base.

Vertical Close-Coupled (VM).This vertical style is desirable

where space is limited.

Vertical Coupled (VC).Minimal floor space required.

Standard "P" base motor used.


Cornell Pump Company • Portland, OregonCORNELL

4

Cornell Quality Features

MODULAR BEARING FRAME

REPLACEABLE SHAFT SLEEVE

BACK PULL-OUT DESIGNFOR EASE OF MAINTENANCE

FULLY MACHINED IMPELLERWITH DOUBLE CURVATURE VANES EXTERNAL HYDRAULIC

BALANCE LINE

SMOOTH CONTOUREDSUCTION FOR IMPROVEDHYDRAULIC PERFORMANCE

DOUBLE VOLUTE DESIGNSTANDARD ON LARGER SIZES

RIGID, HEAVY WALLED CONSTRUCTION

LARGE, DEEP STUFFING BOXFOR EXTENDED PACKING LIFEAND MINIMUM ADJUSTMENTS(MECHANICAL SEALS OPTIONAL)GENEROUSLY SIZED BEARINGS

TO MAXIMIZE B-10 BEARING LIFE

HEAVY, STRESS PROOFSTEEL SHAFT

REPLACEABLE, RECESSEDWEAR RINGS



5

THE EXTERNAL HYDRAULIC BALANCE LINE

To lower pressure in the stuffing box (or seal chamber)and to attempt to limit theinherent axial force created by the impeller, traditional centrifugal pump designs uselarge holes bored through theimpeller. Cornell has a moreeffective method –THEEXTERNAL HYDRAULICBALANCE LINE.

High pressure liquid from the volute passes through thehub ring clearances into thecavity between the stuffingbox and the impeller. Liquidreturns via the balance line to

the region of lower pressure at the pump inlet. This method reduces turbulence, improves hydraulic efficiency, increases the life of packing, mechanical seals and bearings – provides positive control of axial forces. It also reduces wear because sand is not trapped behind the impeller, near the shaft.

CORNELL ADVANCED DESIGNFEATURES THE DOUBLE VOLUTE SYSTEM

The Double Volute System enables Cornell single stage, end-suction centrifugal pumps to easily handle large volume and high pressure jobs.

As the impeller adds energy to the fluids, pressure increases around the periphery of thevolute. On single volute pumps, the increasingpressure acts against the impeller area and creates unbalanced radial forces. By contrast,the Double Volute System effectively balancesthese forces around the impeller to reduce shaftflexure and fatigue.

Cornell’s “DVS” design keeps shafts frombreaking, extends the life of packing andmechanical seals, wear rings and bearings –maintaining high hydraulic efficiency.

Balancedaxial forces

ReducedPressureArea

Sand and siltflushed out

CORNELL METHODExternal HydraulicBalance Line

Area of turbulence

Holes bored in impeller

Sand andsilt buildup

TRADITIONAL METHOD

Unbalancedaxial forces

CORNELL DOUBLE VOLUTERadial thrust is offset and balanced by the double volute design.

Cutwater #1

Cutwater #2


PUMPS

Pump- A mechanical device that convertsmechanical forms of energy into hydraulic energy.

Pump Classifications- Generally pumps can beclassified into two classifications – positive displacement and centrifugal.

Positive Displacement Pumps- Operate by reducing the volume of space within the pumpthat the liquid can occupy. In a reciprocatingpump the piston forces the liquid from the cylinder into the discharge line.

Centrifugal Pumps- Move liquids by increasingtheir speed rather than displacing or pushingthem. The vanes do work on the fluid to increasethe velocity without decreasing the pressure. Thisincreased velocity is then recovered in the casingas increased pressure.

Centrifugal Force- According to Websters, is thatforce which tends to impel a thing, or parts of athing outward from the center of rotation.

Sump- A hydraulic structure that acts as a reservoir from which single or multiple pumps,arranged in parallel, may draw water.

Vortex- The phenomenon by which air enters asubmerged suction pipe from the water surface.Usually a cause of poor pump performance whenthe suction pipe is not adequately submerged.

Manifold- A hydraulic structure used to distributewater under pressure. Can be used to supply fluidto or receive fluid from a parallel arrangement ofmultiple pumps.

ELECTRICAL

Volt- A unit of electrical potential. A volt is thedriving force which causes a current of 1 ampereto flow through a resistance of 1 ohm.

Ampere- A unit of electrical current. The unitused to specify the movement of electrical chargeper unit time through a conductor.

Kilowatt-The unit commonly used to describe electrical power. 1 Kilowatt is equal to approximately 1.34 horsepower.

Power- The rate of doing work.

Power Factor- The percentage of apparent electrical power (Volts x Amps) that is actuallyavailable as usable power.

Ohm- The practical unit to measure electricalresistance. Resistance of a circuit in which a potential difference of one volt produces a current of one ampere.


6

Terminology

TYPICAL CENTRIFUGALPUMP IMPELLER

In centrifugal pumps,water enters the pumpand travels into theimpeller through theimpeller eye. In general,the larger the impellereye, the greater the volume in gallons per minute.

DISTANCEBETWEEN SHROUDS

IMPELLER EYE

EXAMPLE: Reciprocating

EXAMPLE: Centrifugal

Singleor multipledesign

These can be singleand multi-stage openor closed impellers

Piston

Plunger

Diaphragm

Radial Flow

Mixed Flow

Axial Flow

Rotary Gear

Rotary Screw

Rotary Cam



8

perfect vacuum is zero. Absolute pressure of theatmosphere at sea level is 14.7 psi (0 psi gauge).

Vapor Pressure- The pressure exerted when asolid or liquid is in equilibrium with its ownvapor. Vapor pressure is a function of the substance and of the temperature.

Vacuum- Frequently used in referring to pressuresbelow atmospheric. Vacuum is commonly expressedin inches of mercury. 14.7 psi atmospheric pressure equivalent to 30 inches of mercury at sea level.

Head- The vertical height of a static column ofliquid corresponding to the pressure of a fluid atthat point. Head can also be considered as specificwork (FT. LB./LB.) necessary to increase the pressure,velocity or height of a liquid to some value.

Potential Head- (Energy of position) The workrequired to elevate a weight to a certain heightabove some datum or reference plane.

British Thermal Unit (BTU)- The amount of heat required to raise the temperature of onepound of water from 63 to 64 degrees Fahrenheit.BTU’s are the unit commonly used to express the potential energy of fuels used in internal combustion engines.

Shut-off Head- Is the head generated by a pumpwith the discharge valve closed (pump running atzero capacity).

Static Pressure Head- (Energy per pound due topressure). The height to which liquid can be raisedby a given pressure.

Velocity Head- (Kinetic energy per pound). Thevertical distance a liquid would have to fall toacquire the velocity “V”.

Bernoulli’s Theorem- The sum of the three types(elevation, pressure and velocity) of energy (heads)at any point in a system is the same at any other

point in the system assuming no friction losses or the performance of work.

Static Suction Lift- The vertical distance in feet,when the source of supply is below the pump,from the surface of the liquid to the pump centerline.

Static Suction Head- When the liquid supply isabove the pump. The vertical distance from thepump centerline to the surface of the liquid.

SUCTION SUPPLYOPEN TO ATMOSPHEREwith Suction Lift

SUCTION SUPPLYOPEN TO ATMOSPHEREwith Suction Head

NPSHA = PB + LH - (VP + hf)

NPSHA = PB - (VP + LS + hf)

LS

PB

PB

LH

CL

CL

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9

Suction Head- (hs) exists when the liquid supplylevel is above the pump centerline or impeller eye.The total suction head is equal to the static heightor static submergence (in feet) that the liquid supply level is above the pump centerline, less allsuction line losses including entrance loss, plus anypressure (a vacuum as in a condenser hotwell beinga negative pressure) existing at the suction supplysource. Caution – even when the liquid supplylevel is above the pump centerline the equivalentof a lift will exist if the total suction line losses (andvacuum effect) exceed the positive static suctionhead. This condition can cause problems particu-larly when handling volatile or viscous liquids.

Static Discharge Head- Vertical distance frompump centerline to the free surface of the liquid ina discharge tank or point of free discharge.

Total Discharge Head- (hd) Is the sum of:

(1) Static discharge head.

(2) All piping and friction losses on the discharge side including straight runs of pipe, losses at all valves, fittings, strainers, control valves, etc.

(3) Pressure in the discharge chamber (if it is a closed vessel).

(4) Losses at sudden enlargements (as in a condenser water box).

(5) Exit loss at liquid discharge (usually assumed to be equal to one velocity head at discharge velocity).

(6) Plus any loss factors that experience indicates may be desirable.

LS = Maximum static suction lift in feet.

LH = Minimum static suction head in feet.

hf = Friction loss in feet in suction pipe at required capacity.

PB = Barometric pressure, in feet absolute.

VP = Vapor pressure of the liquid at maximum pumping

temperature, in feet absolute.P = Pressure on surface of liquid in closed suction tank,

in feet absolute.

CLOSEDSUCTION SUPPLYwith Suction Lift

NPSHA = P - (VP + LS + hf)

LS

P

CL

CLOSEDSUCTION SUPPLYwith Suction Head

NPSHA = P + LH - (VP + hf)

P

LH

CL

TOTAL STATIC HEAD

STATICDISCHARGE

HEADSTATIC

SUCTIONHEAD

TOTAL STATIC HEAD STATIC

DISCHARGEHEAD

STATICSUCTION

LIFT

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7

Work- The transference of energy by a processinvolving the motion of the point of application of a force, as when there is movement against aresisting force or when a body is given acceleration;it is measured by the product of the force and thedisplacement of its point of application in the lineof action.

HYDRAULICS

Hydraulics- The study of fluids at rest or in motion.

Fluid- A substance which when in static equilibriumcan not sustain tangential or shear forces. This differentiates fluids from solids. However, inmotion, fluids can sustain shear forces because ofthe property of viscosity. A fluid can be a liquid or a gas.

Viscosity- The existence of internal friction or theinternal resistance to relative motion of the fluidparticles with respect to each other. The viscositiesof most liquids vary appreciably with changes intemperature, whereas the influence of pressurechange is usually negligible. Some liquids have viscosities which change with agitation.

Newtonian- A liquid is Newtonian or a “true fluid if its viscosity is unaffected by agitation aslong as the temperature is constant. Example:Water or mineral oil.

Thixotropic- A liquid is thixotropic if its viscositydecreases with agitation at constant temperature.Example: Glues, asphalt, greases, molasses, etc.

Dilatant- A liquid is dilatant if the viscosityincreases with agitation at constant temperature.Example: Clay slurries and candy compounds.

Density- Density is the mass per unit volume of asubstance. It is unaffected by the variations ingravity or acceleration.

Specific Weight- The weight per unit volume of a substance. The two terms are frequently usedinterchangeably, though this is incorrect.

Specific Gravity- The ratio of its density (or specific weight) to that of some standard substance. For liquids, the standard is water (1.0 sp. gr.) at sea level and 60°F.

Pressure- The force exerted per unit area of afluid. According to Pascal’s principle, if pressure isapplied to the surface of a fluid, this pressure istransmitted undiminished in all directions.

Atmospheric Pressure- The force exerted on aunit area by the weight of the atmosphere. Thestandard atmospheric pressure at sea level is 14.7 psi.

Gauge Pressure- Is pressure measured relative tolocal atmospheric pressure. Atmospheric pressureis zero gauge.

Absolute Pressure- The sum of atmospheric pressureand gauge pressure. The absolute pressure in a

3.3 FT.2.3 FT.

1.54 FT.

GASOLINE WATER MOLASSESSP. GR. = 0.7

1 PSISP. GR. = 1.0

1 PSISP. GR. = 1.5

1 PSI

EXAMPLE:

1 atmosphere = 14.7 psi ~ 34 feet water34/14.7 = 2.31

psi =2.31

x SP.GR.Head in Feet

Since water weighs .0361 pounds per cubicinch, a column of water one square inch inarea and one (1) foot high will weigh .433pounds. To increase the pressure at the bottom of the column to one (1) psirequires a 2.31 foot high column of water.



10

Total Head- (Formerly called Total DynamicHead). Equal to the total discharge head (hd)minus the total suction head (hs) or plus the total suction lift.

Net Positive Suction Head Required- (NPSHR)The losses from the suction connection to thepoint in the pump at which energy is added, generally, through the impeller vanes. Determinedby test and dependent on pump design, pumpsize, and operating conditions.

Net Positive Suction Head Available- The energy,above the vapor pressure of the fluid, available atthe pump suction to push the fluid into the pump.Note: NPSHA depends on the system layout andmust always be equal to or larger than the NPSHR.

Cavitation- A result of inadequate NPSHA. Whenpressure in the suction line falls below vapor pressure of the liquid, vapor is formed and moveswith the liquid flow. These vapor bubbles or “cavities” collapse when they reach regions ofhigher pressure on their way through the pump.The violent collapse of vapor bubbles forces liquidat high velocity against the metal, producing surgepressures of high intensity on small areas. Thesepressures can exceed the compressive strength ofthe metal, and actually blast out particles, givingthe metal a pitted appearance.

The other major effects of cavitation are drops inhead, flow and efficiency.

Pipe Friction- The system loses pressure when thewater flowing through the piping encountersresistance. For example, friction occurs along thepipe walls because of roughness. Pressure loss alsooccurs because of turbulence induced by valves,

fittings and changes of section. The Cornell“Condensed Hydraulic Data” book has typicalpipe, valves, and fitting Head Loss Tables.

Capacity- Actual pump delivery (usually in gallons per minute in the U.S.A.).

Horsepower- Power delivered while doing work atthe rate of 550 ft-lb per second or 33,000 ft-lb perminute, .706 BTU’s/sec. or .746 kilowatts.

Hydraulic Horsepower- (Water Horsepower) Therate at which a pump adds useful energy to a fluid.

Brake Horsepower- Total power required by apump to do a specified amount of work. Brakehorsepower equals Hydraulic Horsepower plusmechanical and other losses.

EFFICIENCY

Of a Pump Driver- The percentage of inputhorsepower that is converted to usable brakehorsepower by the pump driver.

Of a Pump- The percentage of brake horsepowerapplied to the pump shaft that is converted tousable water horsepower by the pump. Bearingand seal losses are usually deducted from horsepower.

Rating Curves- (Pump Curve) The most important aspect of any discussion on centrifugalpumps. A graphical representation of a pump’sperformance, including NPSH requirements,horsepower requirements, etc. over its entire operating range.

CAVITATIONEFFECT ON PUMP CAPACITY

CAVITATION

NORMAL PERFORMANCEWITH SUFFICIENT

NPSHA

H – Q

HE

AD

—F

T.

CAPACITY — GPM

CUT OFFPOINT

100

0

HEAD – CAPACITY

HE

AD

—F

T.

CAPACITY — GPM 500



11

System Curve- A graphical representation of therelationship between the Total Head and the flowrate for a given fluid system.

Simple System Curve- Friction loss increases proportionally to the square of the capacity orvelocity.

TYPICAL CURVES

Four typical curves may be classed as follows:

1. Steady Rising Curve or a rising head capacitycharacteristic is a curve in which the head rises

continuously as the capacity is decreased. The rise from best efficiency point to shut-off is about10 to 20%. Pumps with curves of this shape areused in parallel operation because of their stable characteristics.

2. Drooping Curve characteristic is a curve inwhich the head capacity developed at shutoff isless than that developed at some capacities. Whenpumps with drooping characteristics are run onthrottling systems, operating difficulties can occursince the system friction curve can intersect thehead capacity curve at two points. These pumpswill also only operate in parallel when the operatingpoint is below the shut-off head; therefore, paralleloperation should be avoided with this curveshape.

3. Steep-Rising Curve is one where there is a largeincrease in head between that developed at designcapacity and that developed at shut-off. It is bestsuited for operation where minimum capacitychange is desired with pressure changes, such asbatch pumping or filter systems.

• STABLE

• O.K. IN PARALLELOPERATION

STEADY RISING H – Q

HE

AD

—F

T.

GPM

H– Q

• GOOD PERFORMANCE

• MAXIMUM Q

• STABLE AT HEADSBELOW SHUT-OFFHEAD

DROOPING H – Q

HE

AD

—F

T.

GPM

H– Q

100

0

1

10

H – Q

H–Q

H–Q

HE

AD

—F

T.

BH

P

CAPACITY — GPM

BRAKE HORSEPOWER

500

100

0

HE

AD

—F

T.

CAPACITY — GPM 500

100

0

HE

AD

—F

T.

CAPACITY — GPM

NPSHR

500

1

10

90

0

0

BH

P

BHPEFFIC

IENCY

%E

FF.

25

NP

SH

R

FT.



12

4. Flat Curve refers to a characteristic in which the head varies slightly with capacity, from shut-off to design capacity. When wide fluctuations of capacity occur with nearly constant pressurerequirements this is the pump best used.

• LITTLE RISE OVERRANGE

• GOOD FOR CHANGINGQ WITH LITTLEHEAD CHANGE

FLAT H – Q

HE

AD

—F

T.

GPM

H – Q

• SHUT -OFF 140-150%OF BEP HEAD

• STABLE

• GOOD FOR PARALLELOPERATION

• FILTER SERVICE

• SMALL Q CHANGEFOR VARIABLE HEAD

STEEP RISING H – QH

EA

D—

FT.

GPM

H– Q

IN GENERAL

In general, it is desirable to choose

a pump to operate at maximum

efficiency point or slightly to the

left of this point. However, with

pumps, as with all commodities,

the commercial aspect must be

considered. Thus pumps are sold to

operate over a wide range, even out

at the end of the rating curve. If

the NPSH available is sufficient to

prevent cavitation, the pump will

give satisfactory operation.

NOTES:



13

In selecting a pump for a particular job, attentionshould be given to information gathering. Withoutproper and specific information, proper selectionis impossible.

It is often difficult to get information from theuser because he either doesn’t know the answersor doesn’t want you to know about his business.

This can waste a lot of time and energy! You must be persistent in getting the information, or you may supply the wrong pump, resulting inback charges for restocking and, consequently, a dissatisfied customer.

IT CANNOT BE EMPHASIZED ENOUGH! YOUMUST ASK THE RIGHT QUESTIONS.

Questions lead to other questions! Ask questions,even unrelated questions can help! They mighttrigger other questions that are very important tothe proper operation of the pump at the site.

• What are the customer’s preferences?• Is he a critic of some particular type of

pump?• Make of pump – style of pump?• Make of motor – style of motor?• Make of control – style of control?

This will influence your selection. You may havebeen thinking of a Close-Coupled Centrifugalwhen the customer was thinking in terms of aCanned Turbine.

• Establish a meeting of minds.• Get the facts. – Weigh them.

Then, make your selection. It may or may not bethe type of equipment you first thought of! AskWHAT the pump is SUPPOSED TO DO.

• What head is required?

• What capacity is required?• What voltage or power is available?

These can be the openers, but there are many others, depending on the job to be done.

• What is the pumpage?• Is the pumpage hot?

Check the NPSH. Water flashes at 212° F. Checkmaterials of construction. Bronze expands morethan iron. It’s possible that a bronze impellermight come off of a particular shaft.

Check fluid viscosity. If the fluid cools off, it maythicken, and raise the horsepower requirement.

• Is the pumpage cold?

Check the NPSH. Ammonia boils at -28° F. Checkmaterials of construction; extreme cold may causeembrittlement.

• Is the pumpage corrosive?• What is its PH level?

Above 7.0 is alkaline, below 7.0 is acidic. Checkmaterials of construction for compatibility withpumpage. Low PH normally requires brass orstainless steel, high PH normally requires iron or stainless steel.

• What is, the specific gravity of the pumpage?

Acids are normally heavy, as are caustics. Thismeans high horsepower.

H

HQ

BHP

BHP

BHPSP GR 1.1

SP GR 1.0

SP GR 0.8

Q

Fact Finding to Determine Pump Choice



14

The following check list may help you to ask thequestions needed to make the right equipmentchoices:

1. WHAT IS THE PUMPAGE?❏ Vapor pressure

- Does the pumpage have high vapor pressure?- Check NPSH available against NPSH

required. - Does the pumpage have low vapor?

Treat 15 PSI as water.

❏ Is the pumpage explosive? - Check materials of construction. - Non-ferrous materials should be used to

prevent sparking. - Stainless Steel might be desirable. - Quenched glands.

❏ Is the pumpage hazardous to health? - Mechanical seals may be required. - Flushed glands may be required. - Special materials (silver?). - Special pumps – (sanitary type).

❏ Is the pumpage carrying solids?- Special pump designs required.- Heavier volutes, Impellers, or Vanes.- Recirculation?- Hard iron or special materials.- High horsepower required.- Reduced heads.- Pumps should be oversized.

❏ Is the pumpage carrying fibers? - What percent? - Is percentage by weight or volume? - In some cases Delta works quite well. - Self-purging action? - Special pump design required.

❏ Is the pumpage handling food products?- Single Port Impellers.- Slow speed – 5'/sec. velocity is normal.- V-belt drive.

❏ Is the pumpage a slurry or sand?- Again, extra horsepower is needed.- Extra capacity to take care of losses due

to erosion.- Some slurries are corrosive as well as abrasive,

so check materials.

❏ Is the pumpage aerated?- Look out for vapor binding.- Check the source of gas entrainment.- Provide bleed-offs in pump to remove air.

❏ Is the pumpage viscous? - This can easily lead to high horsepower. - Maximum SSU that can be handled by a

centrifugal pumps is about 5000 SSU. - The head-capacity and efficiency curves

are drastically reduced.

2. WHAT IS THE HEAD REQUIREMENT?❏ Is the discharge head constant as in the filling of

a reservoir? (Hooks are O.K. in this curve)

❏ Is the discharge head variable like with direct flows into a distribution system? (Hooks in this curve are bad).

❏ Is the pump to work at more than one head?

❏ Check the efficiency curve. A flat curve is desirable so that the pump will be working near maximum efficiency at both locations.

H

Q

WATER HQ

VISCOUS HQ

Q

H



15

❏ For more than one head or capacity condition, have you considered:- Variable-speed pumps, or multiple pumps?

❏ Is a rising head curve desirable? For a Boiler Feed or Elevator a flat discharge head is better.- Sprinkler irrigation laterals can be added

without a dramatic change in pressure, likeCornell W & Y series.

❏ Is a hook in the discharge head curve detrimental? Yes, if head is subject to variation.

❏ What is the discharge head in terms of- Feet, PSI, PSI G, PSI A absolute, other?

❏ Is the discharge head high pressure – 400 to 10,000 feet? If it is, you might consider multi-stage pumps or pumps in series.

❏ Is the discharge head medium pressure – 100 to 400 feet? If so, you would use a single stage or multi-stage pump.

❏ Is the discharge head low pressure – 0 to 100 feet? In this range you would normally use a single-stage, low speed pump.

3. WHAT IS THE PUMP CAPACITY?❏ Is the pump high capacity? If so, consider mixed

flow or axial flow propeller pumps.

❏ Is the pump low capacity? If so, radial or positive displacement pumps should be considered.

❏ Is the pump medium capacity? Consider radial or mixed flow pumps.

❏ Have you considered dual pumps? Dual pumps have the advantage of stand-by equipment, safety in the event of break down, and usually lower power costs.

❏ Is the pump capacity in terms of GPM, cubic foot per second, or second per feet, or barrels

per day. Be sure to check the capacity terms used. There is a chance for error here.

4. WHAT IS THE SUCTION CONDITION THEPUMP USES TO OPERATE AGAINST?❏ Does it have high suction lift? Medium suction

lift? Low suction lift?

❏ Is the suction lift critical? If it is in excess of the NPSH required for the pump, you should move the pump closer to the surface of the liquid, or raise the static head of the pump suction, or increase the suction pipe size, to reduce suction system losses.

❏ Is the submergence sufficient? Best check the NPSH curve. You might consider the installationof a suction umbrella or a floating platform.

❏ How can you tell if the submergence is sufficient or the suction lift critical for the pump selected? There is only one way; check the manufacturer’s NPSH curves and compareNPSHA with NPSHR.- Is the suction source critical? Are there

periodic low flows in the water source? Do you have shut-off controls on your pump to prevent damage?

- Is the suction source a sump, a closed tank, a pond, a river, or a pipeline?

- Is the suction tank pressurized, if so, what pressure?

- What pressure can the pump stand?

❏ Is the platform for the pump properly designed?- Do you have to double bolt the pump?- Is the system apt to go higher during static

and cause water shock which will damage the pump?

- Is the pump mounted at a river location where cross currents could cut the bank out from beneath it and cause the pump tobe washed away?

- Are there cross currents creating whirlpools and/or aeration that will cause hydraulic instability in the pump?



16

❏ What about elevation? Do you know that suction lift ability decreases approximately onefoot for every 1,000 feet above sea level due to decreased atmospheric pressure at higher elevations?

❏ Is the suction source subject to variation either in level or quantity?

- Is the suction source subject to debris? - Is there a submergence limitation? - Do you have a critical velocity? - Will a vortex form?

❏ Is the suction source properly designed? - Will it be used for more than one pump? - Is the inlet screened? - Are the screens adequate? - Of proper design? - Are the intake structures baffled?

5. WHAT ABOUT MOTORS?❏ What type of motor enclosure is required?

- ODP, WPI, TEFC, TENV?

❏ Is it Explosion Proof?Is a soft start required or is an across the line start O.K.?

❏ Does the user know that motor standards havechanged? While 40° C motors were once standard, they are now special. The 60° C motors are now considered standard; however, 75° C motors are standard when a TEFC enclosure is furnished. 75° C = 167° F.

❏ Does the user know how hot 60° C actually is? Does he realize that he can’t hold his hand on a 60° C motor? (60° C = 140° F)

6. WHAT ABOUT THE TYPE OF PUMP?❏ Has some particular type of pump given better

service?- What has been the history at the site?

❏ Does a Horizontal Close-Coupled Centrifugal do the job? They are low cost and don’t requiremuch room!

❏ Does a Horizontal Frame Mounted do the job? Normal use could be with direct, v-belt drive or variable speed.

❏ Does a vertical pump work best?- A Vertical Frame pump such as a Cornell VC

type?- A Vertical Frame pump of the Line Shaft

type (Cornell VF)?- A Vertical Close-Coupled pump (Cornell

VM)?- A Vertical Can? or Turbine? – Which would

be the best choice?

❏ What about the pump’s materials of construction?- What has been the user’s experience?- Should the pump be all Iron, all Bronze,

Stainless Steel, or Cast Steel?

❏ If the pump should be all Iron, what type of Iron is best?- Hard/Nodular, Ordinary, High Tensile?- Which would be the best? Is the user aware of

all the various types of Iron?

❏ If all Bronze, what type?- Standard Commercial, Acid Resistant, Heavy

Duty?

❏ If Stainless Steel:- 400 Series (410-416), 300 Series (304-316), 17-4 PH, Alloy 20?

❏ If all Steel, what kind:- 1020, 1040, Manganese – Self Hardening?

❏ Besides knowing what particular type of material to use for the pump’s construction, special consideration must also be given to the different metals used for bearings, stuffing boxes, packing, mechanical seals, etc.

7. WHAT ABOUT PIPING?❏ Requirements must be met in piping such as

how long the pipe should be, and what size of pipe will work.



17

- What material should the pipe be constructedof for the type of pumpage? What about the friction coefficient? Is it adequate for the pressure required?

- Will the pipe carry the capacity required?- Is the friction loss too high?- Do you have a velocity adequate for scouring

air/sand?

Provided you have satisfied yourself with the information given, you may then proceed with pump application and selection.

One last question you should ask yourself before providing your bid or recommendation to the customer: Did I ask enough qualifying questions?

NOTES:



18

Selecting the Pump

TO DETERMINE THE SYSTEM TOTAL HEADADD THESE FACTORS TOGETHER IN FEET.

3

1

2

7

4

5

6

SUCTION ENTRANCE LOSS

SUCTION PIPEFRICTION

DISCHARGE PIPEFRICTION

SUCTION LIFT

MISCELLANEOUS LOSSES(VALVES, ELBOWS, ETC.)

DISCHARGELIFT

NEEDED PRESSUREAT END OF LINE

NOTE:BE SURE TO MULTIPLYPRESSURE IN P.S.I. BY 2.31TO CONVERT TO FEET

TYPICAL PUMP INSTALLATION

TOTAL HEAD is the SUM of the following:

1. Suction pipe friction (see Condensed Hydraulic Data Book).

2. Suction lift (vertical distance, in feet, from water surface to center of pump inlet).

3. Suction entrance loss (usually figured at one velocityhead plus foot valve losses

4. Discharge pipe friction (Condensed Hydraulic Data Book).

5. Discharge lift (vertical distance, in feet from pump to high point in system).

6. Pressure, in feet, for service intended (pressure, in P.S.I., x 2.31 equals feet of head).

7. Miscellaneous losses, in feet (for valves, elbow, and all other fittings, see Condensed Hydraulic Data Book).

EXAMPLE 1:For capacity of 320 GPM,total head in feet is determined as follows:

1. .28 Ft. Suction friction (6” steel pipe, 20’ long)

2. 5 Ft. Suction lift

3. 2 Ft. Suction entrance loss

4. 14 Ft. Discharge friction (6” steel pipe,1000’ long)

5. 15 Ft. Discharge lift

6. 100 Ft. (43 P.S.I. x 2.31)

7. 5 Ft. Miscellaneous losses

EXAMPLE 2:For capacity of 600 GPM,total head in feet is determined as follows:

1. .89 Ft.

2. 5.00 Ft.

3. 6.90 Ft.

4. 45.00 Ft.

5. 15.00 Ft.

6.100.00 Ft.

7. 17.30 Ft.

HOW TO SELECT A CENTRIFUGAL PUMP

The pump is selected after all the system data has been gathered and computed. The system TOTALCAPACITY in gallons per minute and TOTAL HEAD in feet must be determined. You should considersuction submergence, NPSH R and A, various speeds, other drives (engine, motor, etc.) and all systemcondition to optimize the selection.

190 Ft. Total Head141 Ft. Total Head



19

SELECTING THE PUMP FOR 600 GPM @ 190 FT. T.H.

At 3600 RPMRefer to the pump performance curve on page 35.The 4WH 40-2, 3560 RPM handles the head andcapacity with 7.00” Impeller at 75% efficiency and14 ft. NPSH required.

At 1800 RPMRefer to the pump performance curve on page 41.The 3HA 30-4, 1775 RPM handles the head andcapacity with 14” Impeller at 71% efficiency and 8 ft. NPSH required.

SELECTING THE PUMP FOR 320 GPM @ 141 FT. T.H.

Refer to the pump performance curve on page 34.The 2.5 WH, 3525 RPM, handles the head andcapacity with 71% efficiency. NPSH required is 11feet. A 20 horsepower 3525 RPM motor is requiredwith a 6.50” impeller.

NOTES:

1. Required Head and Capacity.2. Net Positive Suction Head Available/

Required.3. Pumpage characteristics:

A. Presence of abrasives, size, concentration,specific gravity, other characteristics.

B. Viscosity.C. Temperature.D. Corrosive qualities.E. Presence of other impurities or gases. F. Specific Gravity. G. Vapor Pressure.

4. Service duty cycle.5. Type of materials and fittings in connected

pipe lines.6. Previous experiences with the system.7. Acceptable economic life.8. Desired pump driver and related data.9. Safety or downtime consideration.

Reference: Hydraulic Institute Standards, 13th edition.

DATA REQUIRED FOR MAKING A SATISFACTORY PUMP SELECTION:



20

Multiple Pumps

If you have large or variable pumping requirements,consider installing multiple pumps rather than a single large pump. Multiple pumps allow you to shut down units under reduced-demand conditions, allowing the on-line units to operate at or near peak efficiency. If you have only a large,single pump, under similar conditions your onlyoptions are to throttle the pump or vary the speed.Consequently, your pump could operate atreduced efficiency.

Additionally, you can service or repair multipleunits during low demand periods to avoid totalsystem shut-downs. Often two small pumps havelower NPSHR characteristics than one large pump.When you shop for multiple pump systems, it usually is important to choose pumps with a curveshape that continually rises as the flow reduces.

When you operate pumps in parallel and series,contact the pump manufacturer to ensure warrantability of the equipment for your specificapplication.

PUMPS IN PARALLEL

More than one unit pumping into a common discharge manifold (increases capacity, maintainshead).

Suction

Suction

Common discharge

FLOW IN PARALLEL

TDH (FT.)

FLO

WG

.P.M

.

190 180 170 160 140 120 100 90

200 700 1010 1200 1360

660 760200 540 880 970 1050

860 1460200 540 1890 2170 2410

1080

4RB 40-4 12.5"

5WB 40-2 7"

TOTAL INPARALLEL

GPM

PUMPS IN PARALLEL

200

160

120

TDH

80

40

0 400 800 1200 1600 2000 2400

5WB

4RB

INCREASED FLOW

NOTE: The diagram on this page is intendedto show the parallel concept. It is not intendedto show proper system design (no valves) orinstallation of parallel operation.



21

PUMPS IN SERIES

The discharge of the first stage is piped into the suction of the second stage (maintains flow, increases head).

HEAD IN SERIES

TD

H(F

T.)

1200

120

400

168

186

354

600

163

175

338

0

171

192

363

200

170

190

360

800

155

154

309

1000

141

113

254

G.P.M.

4RB 40-4 12.5"

5WB 40-2 7"

TOTAL INSERIES

GPM

INCREASED HEAD

PUMPS IN SERIES

400

300

TDH200

100

0 200 400 600 800 1000 1200

5WB

4RB

NOTE: The diagram above is intended to showthe series concept. It is not intended to showproper system design (no valves) or installationof series operation.

NOTES:



22

Specific Speed

(NS) The speed at which an impeller would run if it were proportionally reduced in size so as todeliver 1 GPM against a total dynamic head of 1ft.

Specific Speed is a characteristic number whichhas a great deal of meaning to a pump designer.The intent of this description, however, is not todelve into any theoretical discussion, but to give us exposure to the concept, define what specificspeed is, and show how it can have a practicalmeaning to us in our day to day work with pumps.Specific speed is best defined by its formula:

where: n = Revolutions per minuteQ = B.E.P. Capacity in GPM at

Maximum Impeller DiameterH = Head in feet at B.E.P. capacity

Note that the chart below shows us various configurations of impellers used for pumps, ranging from those radial type impellers for centrifugal pumps through mixed flow and axial flow propeller type pumps.

Note also that specific speeds ranging from 500 to4,000 refer to radial flow type impellers; specificspeeds from approximately 4,000 to 10,000 refer to mixed flow type impellers and specific speedsabove 10,000 are usually axial flow type impellers.

Generally, you can predict the possible efficiencyof a pump if you know its capacity at B E.P. andthe specific speed.

Suction Specific Speed (S) is a parameter, or indexof hydraulic design but here it is essentially anindex descriptive of the suction capabilities andcharacteristics of a given first stage impeller.* It isexpressed as:

where: RPM = pump speedGPM = design capacity at best efficiency

point for single suction first stage impellers (at max. dia.)

NPSHR = net positive suction head required in feet (at best efficiency points)

*Note: Suction specific speeds can range between3,000 and 20,000 depending on impeller design,speed, capacity, nature of liquid, conditions ofservice and degree of cavitation.

Cameron Hydraulic Data Indicates: A high suction specific speed may indicate the impeller eyeis somewhat larger than normal and consequentlythe efficiency may be compromised to obtain alow NPSHR. Higher values of S may also requirespecial designs and may operate with some degreeof cavitation. To avoid marginal designs on thesuction side it is desirable for the user or systemsengineer to consult with the Pump Manufacturerfor suggested design, criteria, and to make certainthat the suction conditions finally established willmeet the requirements of the pump selected.

NS =H 3/4

n Q

S=(NPSHR) 3/4

RPM GPM APPROXIMATE SPECIFIC SPEED TO IMPELLER SHAPE

RADIAL FRANCIS MIXEDFLOW

AXIAL

G.P.M.NS= R.P.M.

H 3/4

500 1000 2000 3000 4000 5000 10,000 15,000

CENTRIFUGAL MIXEDFLOW

PROPELLER



23

Affinity Laws

The affinity laws express the mathematical relationship between the several variables involvedin pump performance. They apply to all types of centrifugal and axial flow pumps. They are as follows:

1. With impeller diameter held constant:

Q = Capacity, GPMH = Total Head, Feet

BHP = Brake HorsepowerN = Pump Speed, RPM

2. With speed, N, held constant. Using diameter change rather than speed change in the affinity laws is accurate only for small percentages of cutdown, usually 15% or less.

AFFINITY RELATIONSHIP EXAMPLE

Cornell Model 6RB 13.5” diameter impeller reference speed – 1780 RPM. Proposed operational speed – 2200 RPM.

Speed ratio:

Affinity laws:

Q1 x 1.236 = Q2H1 X (1.236)2 = H2BHP1 X (1.236)3 = BHP2

REFERENCE POINT ON 1780 RPM PERFORMANCE CURVE:

3000 GPM @ 150’ TDH @ 89% EFF. @ 14’ NPSHR

PERFORMANCE AT 2200 RPM:

Q2 = Q1 x 1.236 = 3000 GPM x 1.236 =

3708 GPM

H2 = H1 x (1.236)2 = 150 TDH x 1.53 =

230 TDH

BHP2 = BHP1 x (1.236)3 = 127.7 HP x 1.89 =

241 HP

*Note: NPSHR2 ~ 22’. NPSHR does not changeexactly as the square of the speed ratio, but this isconservative for speed increases. If speed is beingreduced, use the first power of the speed ratio.Refer to factory.

Note: Actual operating conditions depend on thesystem requirements.

A. Q1

Q2

N1

N2=

B. H1

H2=

N1

N2( )

2

C. BHP1

BHP2=

N1

N2( )

3

D. NPSHR1

NPSHR2=

N1

N2( )

2*

A. Q1

Q2

D1

D2=

B. H1

H2=

D1

D2( )

2

C. BHP1

BHP2=

D1

D2( )

3

2200 RPM

1780 RPM= 1.236

3000 GPM x 150' TDH

3960 x .89 EFF.= 127.7 HPHP1 =



24

Pump Engine Selection

3000 GPM @ 155’ TDHCORNELL MODEL 6RBSPEED RANGE 1800 – 2200 RPM89% PUMP EFFICIENCY

BRAKE HORSEPOWER REQUIRED:

PERFORMANCE CURVE BASED ON:500’ Elevation29.38” HG85° F

ACTUAL PUMPING ENVIRONMENT:2500’ Elevation30% Relative Humidity115° F

TOTAL HORSEPOWER REQUIRED:

Pump Requirement 132.0 HPService Factor – 10% 13.2Temp./Humidity Correction – 3% 4.0Elevation Correction – 6% 7.9

TOTAL NET CONTINUOUS HP REQUIRED 163.7 HP

3000 GPM x 155' TDH

3960 x .89= 132 HP

NOTES:



25

Engine Derate Guidelines

1. For every 10° F above rated temperature, derateengine performance 1%.

2. For every 1000 FT above rated altitude, derate engine performance 3% for naturally aspirated four-cycle diesel engines and 1% for turbo charged four-cycle diesel engines.

3. Fan/Flywheel losses – 5-6%.

4. Service factor – 10% (allows for engine wear).

10” Stromag torque limitations – 362 FT-LBS.

DIESEL FUEL: WT. 7.1 LBS/GAL GASOLINE: WT. 5.9 LBS/GAL

TORQUE (FT-LBS) = 5250 x HORSEPOWERRPM

ENGINE RPM ENGINE SPEED - RPM

3306T PERFORMANCE CURVES

950684

TO

RQ

UE

LB–

FT

BS

FC

LB/B

HP

-HB

HP

G/K

W/H

KW

N-MC

A

B

100

RATING CURVES

FUEL CONSUMPTION

120

140

160

180

200

850

750

260

220

1400 1600 1800 2000 2200

0.45

0.40

0.35

280

260

240

220

200

180

160

140

700

650

600

550

MODEL 685T

HO

RS

EP

OW

ER

TO

RQ

UE

(FT.

LBS

)

400

1

2

3

1

2

3

365

375

380

600

550

500

450

230

210

190

170

150

130

110

1600 1800 2000 22001400

B.S.F.C.(LB/BHP-HR)



26

Average Electric Motor Life

HP RANGE AVERAGE LIFE LIFE RANGE(YR) (YR)

Less than 1 12.9 10 - 15

1 - 5 17.1 13 - 19

5.1 - 20 19.4 16 - 20

21 - 50 21.8 18 - 26

51 - 125 28.5 24 - 33

Greater than 125 29.3 25 - 38

The average of all units = 13.27 yr

Source: DOE Report DOE/CS-0147, 1980.

CAUSE OF FAILURE TOTAL FAILURE

(%)

Overload (overheating) 27

Normal insulation deterioration (old age) 5

Single phasing 10

Bearing failures 12

ContaminationMoisture 17

Oil and grease 20

Chemical 1

Chips and dust 5

TOTAL 97

Miscellaneous 3

*Based on the study of 4000 failures over several years.The major factor in the electric motor life is the life of the insulation system.

MOTOR FAILURE SURVEY BY A LARGE SERVICE SHOP*



27

Guide to Optimum Electric Motor Life

1. Supply Voltage:A. Should not be beyond + or - 10% of the

nameplate rating with rated frequency AND IN BALANCE.

B. Voltages should be evenly balanced as close to the reading on the (usually available) commercial volt meter. For continued operation, any voltage unbalance should not exceed 1%. To illustrate the severity of this condition: a 3.5% voltage unbalance will result in approximately a 25% temperatureincrease. Other side effects will be poor efficiency, increased noise and vibration.

2. Ambient Temperature:A. Protect motor from direct sunlight.B. Provide cooling.C. Derate service factors for elevations

above sea level are as follows:

UP TO 3300 FT 1.15 SF6000 FT 1.10 SF10000 FT 1.00 SF

3. Overloading:A. Select your motor carefully to match the

load without using a service factor. WATCH THE RUNOUT.

B. Provide dependable motor starting equipment to protect motor from lightening, single phasing and short cycling. Use the proper overload heater protection.

4. Ventilation:A. Keep screens clean and free from foreign

matter.B. If shelter is provided, insure proper

ventilation.

5. Lubrication:A. Grease bearings properly as per

manufactures instructions.B. Use the proper grease.

6. Location:A. Protect motor from contamination

(moisture, dirt, etc).

EXTENDING THE LIFE OF THE INSULATION SYSTEM

NOTES:



28

Electric Motor Comparisons

UNIT ENERGY SAVING IN DOLLARS PER HORSEPOWER*

Higher Efficiency

LowerEfficiency 72 74 76 78 80 82 84 85 86 87 88 89

70 0.296 0.576 0.841 1.093 1.33272 0.280 0.545 0.797 1.036 1.26474 0.265 0.517 0.756 0.984 1.20076 0.252 0.491 0.718 0.93578 0.239 0.467 0.683 0.78880 0.227 0.444 0.549 0.65 0.75082 0.217 0.321 0.423 0.523 0.620 0.716

Higher Efficiency

85 86 87 88 89 90 91 92 93 94 94.5 95

84 0.704 0.207 0.306 0.404 0.499 0.592 0.683 0.77285 0.102 0.202 0.299 0.394 0.488 0.579 0.700 0.75586 0.100 0.197 0.292 0.385 0.477 0.566 0.653 0.73887 0.197 0.193 0.286 0.377 0.466 0.553 0.63988 0.095 0.188 0.279 0.369 0.456 0.541 0.585 0.62589 0.093 0.184 0.273 0.361 0.446 0.488 0.52990 0.091 0.180 0.267 0.353 0.395 0.436

Higher Efficiency

91 91.5 92 92.5 93 93.5 94 94.5 95 95.5 96 96.5

90.5 0.045 0.090 0.134 0.178 0.222 0.264 0.307 0.34991.0 0.045 0.089 0.133 0.176 0.219 0.262 0.304 0.34591.5 0.044 0.088 0.132 0.174 0.217 0.259 0.300 0.34192.0 0.044 0.087 0.130 0.173 0.215 0.256 0.297 0.33892.5 0.043 0.086 0.129 0.171 0.212 0.253 0.294 0.33493.0 0.043 0.085 0.127 0.169 0.210 0.251 0.29193.5 0.042 0.084 0.126 0.167 0.208 0.248

*Based on 1000-hr/yr operation and 1.0¢/kWh power costs.



29

Electric Control Panel Data

Textile machinery,and other drivenloads requiringsmooth, shocklessstarting.

MOTORREQUIREMENTS

DESCRIPTIONOF

OPERATION

STARTINGCHARACTERISTICS

IN PERCENTOF NORMAL

ADVANTAGES

LIMITATIONS

auto-transformertaps at:

80-65-50%

Current 64 42 25%Torque 64 42 25%

100%

33%33%

100%

Line voltage60%45%

APPROX. PRICECOMPARISON

(% OF TYPE AT)

APPLICATIONS

PART WINDINGSTARTERTYPE PW

PRIMARYREACTOR

STARTER TYPE PR

REACTORSTARTERTYPE R

STAR-DELTASTARTERTYPE SD

AUTO-TRANSFORMER

STARTER TYPE AT

Can be usedwith anystandardsquirrel cagemotor.



Requires a specialmotor with 6 leadsbrought out (Deltawound stator).

Requires a specialmotor in which thestator windings aredivided into two ormore equal parts withsix leads provided.Also dual-voltagemotors can be usedon the lower range.

The motor isconnected to the linethrough the reducedvoltage taps of an autotransformer for thestarting interval andthen directly acrossthe line for runningcondition.

This method requirestwo main or linecontactors to connectthe motor winding indelta connection forrunning. A thirdcontactor is used toform the star pointon the starting step.

Like the star-deltastarter, this starterrequires no externalequipment. Onewinding is connectedto the line for starting.After a time intervalthe second or runcontactor connects theother motor windingto the line in parallelwith the first winding.

A high resistance isconnected in serieswith the motor onstarting and after atime interval thisresistance is short-circuited andmotor is connecteddirectly to the line.

The motor isconnected to theline through thereduced voltagetaps of a reactorfor the startinginterval and thendirectly across theline for runningcondition.

Variable withtape setting

and load.

High torque efficiency.All the power takenfrom the line, exceptfor transformer losses,is transmitted to themotor. Starting currentand torque are easilyadjusted by changingauto-transformer taps.Closed circuittransition.

The star-delta starterprovides low in-rushcurrent with hightorque efficiency,without the use of anyexternal equipment.Normally open circuittransition but closedtransition can beachieved with the useof resistors

Part-winding startingprovides one-stepacceleration at areduced current. Sothat the secondcurrent in-rush is notobjectionable. Closedcircuit transition.

This type providesalmost as smoothstarting as thereactor type starter.The currentbecomes lower andthe voltage at themotor terminalsrises as the motoraccelerates. Closedcircuit transition.

This type providesthe smootheststarting of allreduced voltagestarting methods.More suitable forjogging or inchingservice. Closedcircuit transition.

Torque remainspractically constantfor the first step andpractically consistentat another value forthe second step.

Starting characteristicsdepend on motordesign and cannot beadjusted. Requiresspecial delta woundmotor.

Requires specialmotor or dual-voltagemotor on low range.Torque efficiency isusually poor forhigh speed motors.

Unavoidable powerloss in resistor. Lowtorque efficiency.Duty cycle limitedby thermal capacityof resistor.

Taps must beselected on jobsite to obtainstarting voltagelevel suitablefor the load.

Applications wherethere are limitationson starting voltageand current.Most widely used.

Low startingtorque applications.

Commercial airconditioningequipment.

Geared orbelted drives,and otherdelicateapplications.

80 65%

80 65%64 42%

100% 60% 40% More than 100%More than 100%


1. 45 Bends (together to make Long Radius 90° Ell) 2. 90° Elbow w/ Mitered Bends 3. Suction Spool 4. Air Separator & Float Box 5. Hosing 6. Check Valve

7. Run-Dry (Optional) 8. Vacuum Pump 9. Belt Drive 10. Isolation Valve 11. Pipeline Support

11

1

11

4 DIA.MIN.

114" TO 6"

2

6

10

3

4

58

79


30

Dry Prime Methods

SELECTRICVACUUMPRIME

CONTROLPANEL

(VP-S UNIT)AUTOPRIMINGSENSOR

HOSE VALVE

ENCLOSURE(OPTIONAL)

VACUUM PUMP

1. Bell Suction (if required) w/ Screen 2. 45 Bends (together to make

Long Radius 90° Ell) 3. Same as #2 4. Eccentric "Suction" Reducer 5. Concentric Increaser 6. 90° Elbow w/ Mitered Bends

7. Check Valve 8. Isolation Valve 9. Concentric Increaser 10. Vacuum Priming Chamber (VPS) 11. Pressure Gage & Isolation Cock 12. Pipeline Support

1

122

3 12

10

124" TO 6"

4

5

6 11 7 8 911

4 DIA.MIN.

KEY

KEY

TYPICALAUTO VACUUMPRIME

CORNELLREDI-PRIME®

WITH RUN-DRY™

OPTION



31

Materials of Construction

CLEAR LIQUID PUMPS SERIES W, Y, R AND H

Volute Casing

Wear Rings

Impeller

Impeller Washer

Impeller Key

Impeller Screw

Suction Coveror Backplate

Bracket, Frame

Shaft

Shaft Sleeve

Seal Gland

Packing Gland

Packing Studs

Packing

Lantern Ring

Packing Washer

Fasteners

Product Flush Line

Balance Line

Anti-Cavitation Line

Parts

Standard Materialof Construction

Cast IronBronze Fitted All Iron

StandardHot Oil

ConstructionHigh

PressureAbrasionResistant

StainlessSteel Steel Bronze

** Frame shafts are SP;Close-coupled shafts are SA

Consult Factory

Note: Special Materials of Construction are available. Consult factory.

MATERIAL CODESSM SAE Grade 5

SP Stress ProofEqual MOD. SAE 1144

SS Stainless SteelAISI 416

ST Stainless SteelAISI 416H.T. to 300-325 BHN

SY Annealed 304/316Stainless Steel Tubing

TE Glass-filled Teflon

ZK Zamak-3 or equivalentKS KeystockAISI C1018

BA Bronze (SAE 660)ASTM B144-3B C93200

BP Copper Tubing

BZ Bronze (SAE 40)ASTM B584 C83600

CA Ductile IronNodular NI-QTH.T. to 400-500 BHN

Cl Cast IronASTM A48, Class 30

CP Ductile IronASTM A536-72NOD-1B

PK Graphited Acrylic

SA SteelAISI 1045

SB Annealed Steel Tubing

SC Cast SteelAISI 1030, ASTM A216

SD Stainless SteelAISI 302, 303, 304

SE Stainless SteelAISI 316, ASTM A296-CF8M

SG Stainless SteelH.T. to 400-500 BHN

** **

CI

BA SS SS SS BA

BZ

BA

CI

SG

CI CIC I

C I

SD

PKTEBASMBP

SB

SD

PKTESSSMSB

SB

SM

SB

SD

TEBASMBP

SB

SD

TESSSM

SB

SD

SE

TE

SE

SY

SD

TE

SSSE

SB

SD

TEBASE

SY

CIBABZ

ST ST

KS KS

SD

CP

CP

BABZ

ST

KS

SD

CA

CA

SGCA

ST

KS

SD

SC

SC

CISC

SS

SA

SD

BZ

BA/BZ

BABZ

SE

SD

SE

SE

SDSD

ST

KS

SD

CI

CI C I

C IC I C I C I C I C I

C I or ZK

CI/SS

VF Motor Stand

Base Elbow

Base Elbow Stand Fab. steel or C I

C I Primer Red Oxide

Paint Alkyd Acrylic Enamel



32

Materials of Construction

SOLIDS HANDLING PUMPSSERIES NL, NN, NH,

NON-CLOG, DELTA, NAUTILUS AND FOOD HANDLING PUMPS

Volute Casing

Wear Rings

Impeller

Impeller Washer

Impeller Key

Impeller Screw

Suction Coveror Backplate

Bracket, Frame

Shaft

Shaft Sleeve

Seal Gland

Packing Gland

Packing Studs

Packing

Lantern Ring

Fasteners

Parts

StandardNon-Clog Material

of ConstructionAll Iron

StandardFood

HandlingConstruction

Standard3HM andNautilus

ConstructionHigh

PressureAbrasionResistant

StainlessSteel Steel Bronze

** Frame shafts are SP;Close-coupled shafts are SA

Consult Factory

Note: Special Materials of Construction are available. Consult factory.

MATERIAL CODES

SM SAE Grade 5

SP Stress ProofEqual MOD. SAE 1144

SS Stainless SteelAISI 416

ST Stainless SteelAISI 416H.T. to 300-325 BHN

TE Glass-filled Teflon

ZK Zamak-3 or equivalent

KS KeystockAISI C1018

BA Bronze (SAE 660)ASTM B144-3B C93200

PB Acrylic Packing

BZ Bronze (SAE 40)ASTM B584 C83600

CA Ductile IronNodular NI-QTH.T. to 400-500 BHN

Cl Cast IronASTM A48, Class 30

CP Ductile IronASTM A536-72GR. 65-45-12NOD-1B

PK Graphited Acrylic

SA SteelAISI 1045

SC Cast SteelAISI 1030, ASTM A216

SD Stainless SteelAISI 302, 303, 304

SE Stainless SteelAISI 316, ASTM A296-CF8M

SG Stainless SteelH.T. to 400-500 BHN(SG double wear rings haveminimum 50 BHN difference)

** **

CI

SS SS SS SS BA

BZ

SS

CICI

SG

CI CIC IC I

CP

SD

PK

SD

PBTE

SM SSSM SM

SD

TE

SM

SD

TE

SM

SD

SE

TE

SE

SD

TE

SE

SD

TE

SE

CI

ST STSTKSKS

SD

CP

CPCP

CI

STKS

SD

CA

CA

SGCA

KS

SD

SC

SC

CISC

STSTKS

SD

BZ

BA/BZ

BABZ

SE

SD

SE

SE

SDSD SD

CI

CIC I

C IC I C I C I C I C I

VF Motor Stand

Base Elbow

Base Elbow Stand Fab. steel or C I

C I Primer Red Oxide

Paint Alkyd Acrylic Enamel



33

B-10 Bearing Life Calculations

PUMP ASSEMBLY SEAL VOLUTE TYPE SLEEVE

Vertical

A11535 3.00" O.D.Single Single

IMPELLERDIAMETER

13.56"

RPM

1760

BEPSUCTIONHEAD

4 x 4 x 14T VC18DB

1300

TOTAL

RADIAL 667-lb.70.74176

667.5-lb.

SHAFT: B3172, STRESS PROOF

B10 LIFE HRS. 59,189 236,729 .0071-in.

@ SleeveShoulder

FATIGUESAFETYFACTORS

@ Hub

FATIGUE STRESS DETAILS

@ SLEEVE SHOULDER

@ HUB SHOULDER

BENDING

5573 9308

5573 15,785645

DESIGN POINTS

DIFF.HEAD

GPM % EFF. HP SPECIFICGRAVITY

0 ft 200 ft 420 58.0 37 1.00

THRUST @ IMPELLER IMPELLER WT.

AXIAL 1233-lb. 1303.9-lb.

FRAME BEARINGS

BEARING NO.

THRUST

Pump End 6316

Radial Only

Opp. Pump End D7316

Axial & Radial

DEFLECTION@ SUCTIONWEAR RING

6.33 5.46

COMBINEDFATIGUE

TORSIONALSHEAR

SHEARTENSION

6000 6247

212 1259 18,328



34

Model 2.5WH: 3600 RPM-60 Hertz

30 HP

10 HP

25 HP

20 HP15 HP

7.5" DIA.

5.5" DIA.

6" DIA.

6.5" DIA.

7" DIA.

18 FT. (5.5 M)

NPSH REQUIRED25 FT. (7.6 M)

12 FT. (3.7 M)

8 FT. (2.4 M)

72

65

79

65 7276

76

68

68

60

60

125100755025

CUBIC METERS PER HOUR

CAPACITY U.S. GALLONS PER MINUTE

100 200 300 400 5000 6000

225

175

125

75

25

FE

ET

80

70

60

50

40

30

20

10

ME

TE

RS

100

150

200

250

50

TO

TA

L D

YN

AM

IC H

EA

D

52.5"3"1357.50"ENCLOSEDVARIOUS

StyleSpeed Impeller Dia. N SSolids Dia.

HP x .746 = KWGPM x 3.785 = Liters/MinuteGPM x .227 = Cubic Meters/HourInches x 25.4 = MillimetersFeet x .305 = Meters

No. vanesDischargeSuction

SINGLE VOLUTE MOUNTING CONFIG.: CC, VM, F, VF, EM, VC

3525

04/27/04

Performances shown are for Cool Water, Close-Coupled Electric configuration with Packing. Other mounting styles or liquids may require horsepower and/or performance adjustments.

MAXIMUM IMPELLER DIAMETER

FOR FULL MOTOR LOAD

FOR FULL MOTOR LOADPLUS 15% S.F.

HP

20

15

10

7.5

A (7.0")

B (6.44")

C (5.50")

D (4.88")

B+ (6.88")

C+ (5.88")

D+ (5.31")

Clear Liquid Pump

PERFORMANCE

CURVES



PERFORMANCE

CURVES

35

Model 4WH: 3600 RPM-60 Hertz

Performances shown are for Cool Water, Close-Coupled Electric configuration with Packing.Other mounting styles or liquids may require horsepower and/or performance adjustments.

1/11/06

75

125

175

225

25

81

81

79

79

75

75

70

70

60

60

25 FT. (7.6 M) NPSH REQUIRED

20 FT. (6.1 M)

15 FT. (4.6 M)

12 FT. (3.7 M)

50 HP

40 HP

30 HP

25 HP20 HP

15 HP

5" DIA.

5.5" DIA.

6" DIA.

6.5" DIA.

7.06" DIA.

0

FE

ET


30025020015010050

70

60

50

40

30

20

10

ME

TE

RS

U.S. GALLONS PER MINUTE

14001200

TO

TA

L D

YN

AM

IC H

EA

D

CAPACITY0 1000800600400200

50

200

150

100

54"5"21071.19"ENCLOSEDVARIOUS





3560


FOR FULL MOTOR LOAD


HP

50

40

30

25

20

15

7.06"

6.62"

6.25"

5.88"

5.50"

5.00"

7.00"

6.44"

6.12"

5.81"

5.38"

Clear Liquid Pump



36

Model 5WB: 3600 RPM-60 Hertz


7/25/00

3560

60

75 HP

60 HP

50 HP

40 HP

8" DIA.

7.5" DIA.

7" DIA.

300

75

125

175

225

275

90

100 HP

NPSH REQUIRED28 FT. (8.5 M)

250

200

150

100


ME

TE

RS

20

30

40

50

60

70

80

50 100 150 200 250 300


FE

ET

350

8.31" DIA. 50 60 70

13 FT. (4.0 M)

16 FT. (4.9 M)

75

79

79

75

70

22 FT. (6.7 M)

Suction Discharge No. vanes


Solids Dia. SNImpeller Dia.Speed Style

VARIOUS ENCLOSED .97" 1821 6" 5" 6

14001200

TO

TA

L D

YN

AM

IC H

EA

D

CAPACITY0 1000800600400200

50



FOR FULL MOTOR LOAD


HP

100

75

60

50

40

8.31"

8.19"

7.62"

7.25"

6.75"

8.31"

8.00"

7.56"

7.12"

PERFORMANCE

CURVES

Clear Liquid Pump



37

Model 5YB: 3600 RPM-60 Hertz

0

50

100

150

200

250

300

350

400

450

1600

350

8484

82

8280

80

75

75

70

7060

30 FT. (9.1 M)

28 FT. (8.5 M)20 FT. (6.1 M)

16 FT. (4.9 M)

15 FT. (4.6 M) NPSH REQUIRED

150 HP

800 10000 1200 1400





DOUBLE VOLUTE MOUNTING CONFIG.: CC, VM, F, VF, EM, VC

3560

7/25/00

125 HP

100 HP

75 HP

60 HP

7.5" DIA.

8" DIA.

9" DIA.

10" DIA.

10.09" DIA.140

FE

ET

120

100

80

60

40

20

ME

TE

RS

TO

TA

L D

YN

AM

IC H

EA

D


CAPACITY U.S. GALLONS PER MINUTE

30025020015010050

200 400 600



FOR FULL MOTOR LOAD


HP

200

150

125

100

75

10.09"

9.81"

9.31"

8.62"

7.88"

10.09"

9.62"

9.06"

8.25"

PERFORMANCE

CURVES

Clear Liquid Pump



38

Model 4RB: 1800 RPM-60 Hertz



6/99

1775





ME

TE

RS

10

20

30

40

50

60

50 100 150 200 250 300


FE

ET

350

0

12.75" DIA. 60 70 75

8 FT. (2.4 M)

10 FT. (3.0 M)

8083

85

8583

15 FT. (4.6 M)

20 FT. (6.0 M)

80

7570

40 HP

30 HP25 HP

20 HP15 HP

10 HP

12" DIA.

11" DIA.

10" DIA.

9" DIA.

8" DIA.

NPSH REQUIRED

50 HP

25

75

125

175

14001200

TO

TA

L D

YN

AM

IC H

EA

D

CAPACITY0 1000800600400200

50

200

150

100



FOR FULL MOTOR LOAD


HP

50

40

30

25

20

15

10

12.75"

11.88"

10.88"

10.38"

9.69"

8.88"

7.75"

12.62"

11.38"

10.75"

10.12"

9.25"

8.25"

PERFORMANCE

CURVES

Clear Liquid Pump



39

Model 6RB: 1800 RPM-60 Hertz

13.5" DIA.13" DIA.

12" DIA.

11" DIA.

89

89

87

87

85

85

80

80

75

75

125 HP

100 HP

75 HP

60 HP

12 FT.(3.7 M.)

15 FT.(4.6 M.)

NPSH REQUIRED18 FT.(5.5 M.)

250

4000

10

20

30

40

50

60

80

U.S. GALLONS PER MINUTECAPACITY

100 200 300 400 500 600 700


800

TO

TA

L D

YN

AM

IC H

EA

D

ME

TE

RS

70

FE

ET

350030000 25002000150010005000

225

200

175

150

125

100

75

50

25

900






1780

1/00



FOR FULL MOTOR LOAD


HP

125

100

75

60

13.31"

12.50"

11.62"

11.06"

13.00"

12.00"

13.50"

11.50"

PERFORMANCE

CURVES

Clear Liquid Pump



40

Model 6RB: Various RPM-60 Hertz

220013.50"ARPMTRIMHQ HQ

B12.50"13.50"

TRIM

22002000RPM HQ

C

11.62"12.38"13.50"TRIM

220020001800RPM HQ

D

11.38"12.25"13.50"TRIM

200018001600RPM

13.50"

DIAMETER FULL

N SSolids Dia.




VARIOUS

9/99

300

325

90

100

A

B

C

D

89

89

8580

7060508 FT.(2.4 M.)

13 FT.(4.0 M.)

15 FT.(4.6 M.)

NPSH REQUIRED23FT.(7.0 M.)

250 HP

200 HP

150 HP125 HP

100 HP

900

75

30


StyleSpeed Impeller Dia.

275

250

4000

40

50

60

80


100 200 300 400 500 600 700


800

TO

TA

L D

YN

AM

IC H

EA

D

ME

TE

RS

70

FE

ET

350030000 2500200015001000500

225

200

175

150

125

100


HP, efficiency and NPSHR are for full diameter impellers only and may vary somewhat for less than fulldiameter impellers.

PERFORMANCE

CURVES

Clear Liquid Pump



41

Model 3HA: 1800 RPM-60 Hertz

6/99

1775




175

150

125

100

75

50

25

15.22" DIA.

15" DIA.

14" DIA.

13" DIA.

12" DIA.

11" DIA.

71

71

70

70

6560

60 HP

50 HP

40 HP

30 HP

25 HP

20 HP

5 FT.(1.5 M.)

6 FT.(1.8 M.) NPSH REQUIRED

8 FT.(2.4 M.)

0 005004003002001 600 700



800

25 50 75 100 125 150 175

275

250

10

20

30

40

50

60

80

TO

TA

L D

YN

AM

IC H

EA

D

ME

TE

RS

70

FE

ET

225

200





FOR FULL MOTOR LOAD


HP

100

75

60

50

40

30

15.22"

14.50"

13.56"

12.56"

11.81"

11.06"

15.06"

13.00"

12.31"

12.38"

11.50"

PERFORMANCE

CURVES

Clear Liquid Pump



42

Model 4x4x14T: 1800 RPM-60 Hertz

8 FT. (2.4 M.)

4555

65 70 72 7476 77

78

9/27/00

1760




Solids Dia. SNImpeller Dia.Speed

100

150

200

250

50

200 400 600 800 10000

CAPACITY

TO

TA

L D

YN

AM

IC H

EA

D

1200 1400

350

1600

75

125

175

225

275

40

30

20

10

ME

TE

RS


24 FT. (7.3 M.) NPSH REQ’D.

20 FT. (6.1 M.)

15 FT. (4.6 M.)10 FT. (3.1 M.)

20 HP 25 HP

30 HP

40 HP

50 HP

60 HP

75 HP

10" DIA.

11" DIA.

12" DIA.

12.5" DIA.

13" DIA.

13.5" DIA.

14" DIA.

FE

ET


30025020015010050

80

70

60

50

Style

VARIOUS ENCLOSED 3" 1310 4" 4" 2


PERFORMANCE

CURVES

Solids Handling Pump



43

Model 6NHTA: 1800 RPM-60 Hertz

75 HP

60 HP

50 HP40 HP

30 HP

14" DIA.

13" DIA.

12" DIA.

11" DIA.

10" DIA.

15 FT. (4.6 M.)

18 FT. (5.5 M.) NPSH REQUIRED

15 FT. (4.6 M.)

10 FT. (3.0 M.)

83

83

82

82

80

80

75

75

7060

50

12/11/00

1770





VARIOUS ENCLOSED 3" 2120 6" 6" 2

200 300 400 500 600 700


30000 25002000150010005000

225

200

175

150

125

100

75

50

25

FE

ET

70

ME

TE

RS

TO

TA

L D

YN

AM

IC H

EA

D

275

250

10

20

30

40

50

60

80


100


PERFORMANCE

CURVES

Solids Handling Pump



44

Model 6NHPP: Various RPM-60 Hertz

60

60

70

70

75

75

6/99

VARIOUS

SINGLE VOLUTE MOUNTING CONFIG.: F, VF, EM, VC



10

20

30

40

50

60

70

80

90

0500 1000 1500 2000 25000 3000 3500

100

110

FE

ET

ME

TE

RS

TO

TA

L D

YN

AM

IC H

EA

D



100 200 300 400 500 600 700 800

700 RPM

800 RPM

900 RPM

1000 RPM

1100 RPM

1200 RPM

1300 RPM

1400 RPM

29 FT. (8.8 M.) NPSH REQUIRED

20 FT. (6.1 M.)

12 FT. (3.7 M.)

40 HP

30 HP

7.5 HP10 HP

15 HP20 HP

25 HP

4000

30

5

10

15

20

25


13.5" ENCLOSED 4"x6" 2600 6" 6" 1


PERFORMANCE

CURVES

Food Processing Pump



45

Specification Guide

CORNELL SOLIDS HANDLING PUMPS

Detailed Cornell specifications are available using Cornell’s Centrific© specification program. For more information, contact the factory.

General RequirementsFurnish and install ( ___ ) solids handling, end suction, centrifugal pumps. Pumps must have continually rising performance curves to shut-off. Pumps shall be manufactured by Cornell PumpCompany or approved equal and warranted for two years from date of shipment. Equals shall be considered if submitted by contractor prior to bidding. Contractor must certify in writing that alternate products are of equal performance and construction.

Design Conditions

Pump model: _______________ Temperature: _______________ °F

Design capacity: _______________ U.S. GPM Min. efficiency at design point: _______________ %

Design total head: _______________ Ft. NPSHR: _______________ Ft.

Shut-off head: _______________ Ft. Suction size: _______________ In.

Max. solids size: _______________ Diameter Discharge size: _______________ In.

Max. speed: _______________ RPM Rotation: _______________ °

Min. motor: _______________ HP

ConstructionThe pump casing shall be of the back pull-out design with heavy sections to provide long life underabrasive and corrosive conditions. Volute and backplate are to be fine grain cast iron ASTM A48 Class 30 with suction and discharge connection to be ANSI 125# flange connections. A contoured voluteclean-out plug can be provided as an option. All mating surfaces shall have a register fit to ensure properalignment.

ImpellerThe impeller shall be of heavy section cast iron ASTM A48 Class 30 with the (two/three)-port Deltadesign. Impellers for 4-inch and larger pumps will have back vanes to reduce axial thrust and lower thestuffing box pressure.

Internal vane edges shall be well-rounded to present smooth flow. The impeller shall have a straight,non-tapered, bore, be dynamically balanced, be keyed to the shaft and further secured with a stainlesssteel washer and a stainless steel impeller lock screw.

Stuffing BoxThe stuffing box shall be integral to the backplate and constructed of ASTM A48 Class 30 cast iron. An extra deep split gland with lantern ring shall be used and designed for (grease/water) seal.

Optional: A _____ -inch single/double mechanical seal, John Crane or equal shall be supplied, with provisions for a water flush. The seal shall be equipped to use clean outside water or filtered pumpagefor lubrication and cooling.

A 50 micron filter element shall be used for filtered pumpage. No flush is required for single seal.



46

Wear RingsA single suction wear ring shall be of the peripheral type requiring no adjustment. It shall be press fitinto position and replaceable in the field. The ring shall be constructed of ASTM A48 Class 30 cast iron(special materials are available upon request). An additional impeller wear ring of 50 Brinnell hardnessgreater than the case ring can be furnished as an option.

ShaftShaft shall be stressproof steel (AISI 1040 or equivalent), accurately machined and polished and of sufficient size to transmit full driver output. The shaft shall have a minimum diameter of _____ incheson the pump end bearing and a minimum diameter of _____ inches inside the shaft sleeve. The steps inthe shaft shall be properly radiused to reduce stress concentrations. To promote longer seal and bearinglift, the maximum allowable shaft deflection registered at the suction wear ring will be _____ inches.This information shall be supplied and documented by the pump manufacturer.

Shaft SleeveShaft shall be protected by a renewable shaft sleeve which extends through the stuffing box and underthe gland of 4-inch and larger pumps. The sleeve shall be grooved on the inside for an O-ring to prevent leakage along the shaft and shall be positively locked to prevent rotation on the shaft. The sleeve shall be a minimum of _____ inches thick and constructed of AISI 416 stainless steel.

Optional ConstructionAISI 316 or 420 stainless steel, AISI 420 heat treated stainless steel, or bronze.

Bearing Frame and BearingsThe bearing frame shall be of one-piece ASTM A48 Class 30 cast iron end covers at both ends. Bearingframes shall be designed (on 4-inch or larger pumps) so that the complete rotating element can beremoved from the casing without disturbing the piping.

Bearings shall be of the roller or ball type and of sufficient size to withstand the radial and axial thrust loads incurred during service. The pump end and drive end bearings shall have in excess of _____hours B-10 bearing life. The B-10 bearing life shall be calculated and documented by the pump manufacturer.

Bearing LubricationThe bearings shall be (grease/oil) lubricated with fittings provided to facilitate lubrication.

Suction Elbows (may be required on vertical units)Suction elbows shall be of one-piece cast iron, heavy section construction with a bolted and contouredclean-out plug. The base shall be of sufficient strength to support the entire weight of the assembledpump and of sufficient height so that no part of the elbow will touch the floor.

MotorsThe motor shall be vertical/horizontal solid shaft type, minimum:

Motor shall be:__________HP; __________RPM; __________Volts; __________Phase;

__________Hertz; __________ODP (TEFC); __________Service factor.

*The above specification is intended to be a representative sample only. Cornell’s Centrific© specification program is available for detailedCornell specifications.



47

Lubrication Instructions

ELECTRIC MOTORS

Ball Bearing Lubrication

NOTE: If lubrication instructions are shown on motor, they will supersede these general instructions.

Bearings in motors are greased at the factory before shipment.

Lubrication requirements vary with speed, power, load, ambient temperatures, exposure to contaminationand moisture, seasonal or continuous operation and other factors. The brief recommendations whichfollow are general in nature and must be coupled with good judgement and consideration of the application conditions. For regreasing periods refer to the table below. When adding grease be sure thegrease and fittings are absolutely clean.

Grease used for these bearings should be equivalent to one of the following manufacturer’s products:G.E. Long Life Grease No. D6A2C5Mobil Mobillux No. EP2Shell Alvania EP2Texaco Multifak No. 2

To lubricate electric motor bearings, use a hand-operated grease gun only. Pump grease into fittinguntil new grease appears at pressure relief plug. For minimum possibility of over-greasing and for bestresults, lubricate when the motor is not running.

Bearings will become unusually hot until excess grease escapes from the relief plug.

End of season: Pump in grease until old grease is expelled from relief plug. Store.

Beginning of season: Start up motor. Let motor run until surplus grease is expelled.

Recommended Regreasing Periods for Motors:

HORSEPOWER

1.5 to 7.5 10 to 40 50 to 150

Total Running Time 2,000 hours 1,500 hours 1,000 hours

8-Hour Day 36 weeks 27 weeks 18 weeks

24-Hour Day 12 weeks 9 weeks 6 weeks


GREASE LUBRICATED FRAME PUMPS

If the frame is oil lubricated (denoted by a “K” on the serial number plate and view gauge on side of the frame), see “Oil Lubricated Frames Pumps.” Bearings in all frames are greased at the factory beforeshipment.

Lubrication requirements vary with speed, power, load, ambient temperatures, exposure to contaminationand moisture, seasonal or continuous operation and other factors. The brief recommendations whichfollow are general in nature and must be coupled with good judgement and consideration of the application conditions. For regreasing periods refer to the table below. When adding grease be sure thegrease and fittings are absolutely clean.

Grease used for these bearings should be equivalent to one of the following manufacturer’s products:G.E. Long Life Grease No. D682C5Mobil Mobilux No. EP2Shell Alvania EP2Texaco Multifak No. 2

To lubricate frame bearings, remove the plastic cover from the zerk fittings and be sure the fitting andend of the grease gun are clean. Use a hand operated grease gun only and pump a small amount ofgrease into each bearing cavity. The surplus grease will go through the bearing and into the center partof the frame. For approximate quantity, refer to the table below.

First determine frame size (located on serial number plate). Example: 5HH-65B4 4NNT-VF1610YB-F18DB 6NHTA-VC18 4RB-EM16

Recommended Regreasing Periods For Frames:


48

3 pumps

Total Running Time

10-1218 - 18D

2,000 hours

2 cubic inches

2 - 5 and 11

8 Hour Day Service

24 Hour Day Service

Approximate Amount ofGrease per Line Fitting

ApproximateNumber of Pumps 12 pumps

.5 cubic inch

12 weeks

36 weeks

6 weeks

18 weeks

1,000 hours

FRAME SIZE

6-7-8-1660B4 through 68B4

6 pumps

1.25 cubic inches

9 weeks

27 weeks

1,500 hours



OIL LUBRICATED FRAME PUMPS

If the frame is grease lubricated, see “Grease Lubricated Frame Pumps.”

The ball bearings are lubricated by the oil in the frame housing. Add oil through the pipe plug openingat the top of the housing and fill to the level indicated on the side of the housing. Be careful to keep outdirt and moisture. The oil level must be maintained; check and fill when pump is not operating. Thetype and grade of oil used is very important for maintenance-free operation.

Oil used should be a turbine oil equivalent to one of the following manufacturer’s products:Oil Temperature up to 150° F Oil Temperature Over 150° F

ISO VG32 ISO VG68Mobil DTE 797 Mobil DTE Oil Heavy MediumLubriplate HO-0 Lubriplate HO-2Chevron Turbine Oil GST 32 Chevron Turbine Oil GST 68Shell Turbo T Oil 32 Shell Turbo T Oil 68

If checking the oil temperature is not feasible, measure the bearing frame temperature at the drain connection. In general, the bearing frame temperature will be approximately 10° F lower than the oiltemperature. Oil recommendation is based on a minimum of 70 SSU at operating temperature.

Lip Seals (Grease)All oil-filled frames will have lip seals in their bearing covers. All lip seals must be lubricated throughthe grease fittings placed in the bearing cover at either end of the frame. Lubricate with a small amountof multiple-purpose grease after every two to six months, depending upon environment.

IMPORTANTA. Oil level must be correct before unit is started.B. Oil lubricated frames must be installed horizontally and level.C. Grease lubricated motors and frames must be maintained per instruction accompanying

the pump. Grease code EP-2 is recommended for most applications.

Bearing temperatures to 160° F are normal. Temperatures over 200° F are too high. The human hand cannot estimate high temperatures. Use a thermometer or other device for temperature measurement.

49

OIL LEVEL INDICATOR



50

Start-up Check List

Before the start-up of any pump, a careful check must be made to insure that all is in order.

A pump must not be started until compliance is reached on all the applicable points above and any others specified in the “Operation and Maintenance Manual” supplied with the pump. Failure to doso may cause severe damage to equipment and/or personal injury. It may also void the warranty.

❏ 1. Re-read all instructions and check for compliance on each point.

❏ 2. Piping must be clean and free of debris

and obstructions, gaskets in place and all

joints secure.

❏ 3. Are all thrust blocks and supports

adequate?

❏ 4. Are screens in place?

❏ 5. Check the valves and blow-offs for

proper position.

❏ 6. Make sure support systems are in

place and functioning, such as special

lubrication, frame oil, etc.

❏ 7. Check the power supply voltage with the

motor name plate.

❏ 8. Are belts and shaft couplings properly

adjusted and aligned and guards in place?

❏ 9. Does the pump rotate freely?

❏ 10. Prime the pump.

❏ 11. Check pump rotational direction. (VERY SHORT on/off power pulse).

❏ 12. Comply with all seal or packing

operation and start-up instructions.

❏ 13. Monitor the motor temperature.

❏ 14. Note the operating temperature of

frame bearings (if any).

❏ 15. The pump may be checked for

shut-off pressure with the pump

performance curve.

❏ 16. Fill the system slowly.

❏ 17. Do not operate any pump without properly priming it, unless it has been specifically designed for such operation.

❏ 18. New pumps must not be started and

stopped frequently. If possible, permit the

unit to run until operating temperature

is reached.

NOTE: Large motors must not be started

and stopped more than five times per hour.



51

Pump Troubleshooting Guide

Align. Replace Shaft.

SYMPTOMS

Failure to pump

Driver overloaded

Excessive noise

Premature bearing failure

Rapid wear on coupling cushion

Electric motor failure

CORRECTIONSCAUSES

Pump not properly primed. Speed too low or head too high. Not enough head to open check valve. Air leak. Plugged suction. Excessive suction lift.

Reduced performance

Air pockets or small air leaks in suction line.Obstruction in suction line or impeller.Insufficient submergence of the suction pipe.Excessively worn impeller or wear ring.Excessive suction lift.Wrong direction of rotation.

Prime pump correctly.Consult Cornell Factory.Consult Cornell Factory.Check and rework suction line.Unplug suction.Consult Cornell Factory.

Locate and correct.Remove obstruction.Consult Cornell Factory.Replace impeller and/or wear ring.Consult Cornell Factory.See start-up instructions.

Reduce speed.Consult Cornell Factory. Consult Cornell Factory. Trim impeller.Consult Power Company.Support piping properly.Loosen packing gland and nuts.

Align all rotating parts.Consult Cornell Factory. Dislodge obstruction.Replace bearings.Replace.Correct suction piping.See start-up instructions.

Speed higher than planned.Liquid specific gravity too high.Liquid handled of greater viscosity than water.Impeller diameter too large.Low voltage.Stress in pipe connection to pump.Packing too tight.

Misalignment. Excessive suction lift Material lodged in impeller. Worn bearings. Impeller screw loose or broken. Cavitation (improper suction design). Wrong direction of rotation.

Balance line plugged or pinched. Worn wear rings. Misalignment. Suction or discharge pipe improperly supported. Bent shaft. Water or contaminates entering bearings. Lubrication to bearings not adequate. Wrong type of lubrication.

Overloads.

High or low voltage. High electric surge. Bearing failure. Cooling vent plugged (rodent, leaves, dirt, etc.). Moisture or water in motor.Poor electric connection.

Misalignment. Bent Shaft.

Unplug or replace. Replace. Align all rotating parts. Correct supports. Replace Shaft. Protect Pump from environment. See Lubrication Instr. (O&M Manual). See Lubrication Instr. (O&M Manual).

Check amperage. Do not exceed nameplate full load amperage. Check voltage with voltage meter. Monitor voltage and consult Power Co. Change bearings in motor. Install proper screens. Protect Pump from environment.Turn power off, clean and check connections.



52

Air Leaks

AIR MAY BE ASPIRATEDTHROUGH THE PACKING AT

HIGH SUCTION LIFTS

PUMPDISCHARGE

BALANCELINE

SMALLLEAKS

INJECTION FLOW FROMTHE PUMP DISCHARGE

STOPS AIR

LARGEBUBBLES

PUMPAGELEVEL SUCTION

LIFT

FL

OW

LIQUID

AIR

When the pump is operating at a high suction lift, it may aspirate air through the packing which will migrate to the suction via the balance line. This is corrected by injecting liquid from the pump discharge to an annular spacer in the packing area called a lantern ring.

Small bubbles become large bubbles in the impeller eye. This will cause thepump to lose performance, efficiencyand possibly prime.



53

Packing, Wear Rings & Coupling Alignment

IMPELLERWEAR

SURFACE WEARRING

RUNNINGCLEARANCE

GLANDNUTS

PACKINGGLAND

GLANDLEAKAGE

PACKING

PACKING PULLERPacking puller used whenreplacing packing

MOTOR STRAIGHT EDGE PUMP FRAME

MOTOR STRAIGHT EDGE PUMP FRAME MOTOR CALIPER PUMP FRAME

MOTOR CALIPER PUMP FRAME

Reinstall coupling guardbefore start-up.

Reinstall coupling guardbefore start-up.

Correct Alignment

Incorrect Alignment

Running clearance for new pumps isabout .010 inch on a side. If wearincreases this to .032 inch, the wearring should be replaced and theimpeller repaired or replaced. Wearmay be caused by abrasives in thepumpage, unsupported piping loads,or other causes.

Tighten the gland nuts 1/4 turnevery ten minutes until a leakage of only 40–60 drops per minutes is achieved. If the packing must be replaced, a packing puller may be needed.

NOTES:



54

Pump Care

Ever had the brown-grass blues?Have you suffered through costlypump repairs and devastatingdowntime? If you have answeredyes to either of these questions, youneed regularly scheduled pumpinspection and maintenance.

Why is the heart of the irrigation system often neglecteduntil it fails? The answer is simple.Pumps have always been a mystery.Remember the old cliche, “If it’snot broke, don’t fix it”? It musthave been created for pumps.Surprisingly, the required pumpmaintenance ratio per hour ofwork performed is extremely low.

After 36 years of being a pumpdoctor, my best advice is:

• Purchase high quality equipment because the pump is the heart of your system

• Know and understand your equipment

• Conduct regular inspections and keep records and notes

• Use common sense by calling for help when you run into a problem you can’t solve

The days of cheap energy aregone for good. To get the mostfrom each kilowatt hour, it’sabsolutely essential to keep thepump and motor in good repair.Efficiency losses due to wear orneglect will add up to big bucks in operating costs.

CLOSE COUPLED END SUCTION PUMP

ImpellerShower Curtain

ShieldElectric motor

Pump end bearing

Packing

Wear rings

THE STUFFING BOX

Grease cup

Packing gland

Motor shaft

Lantern ring

Sleeve

Impeller

Packing

These are the principal components of a horizontal (frame or close-coupled)mount pump. Pumps need regular maintenance, just like other equipment.

This is a standard packing stuffing box with a grease cup and a lantern ring.You can easily adjust the packing gland and grease cup.



55

INSPECTING THE PUMP

A typical inspection includesa look and walk around. Regularinspections help you develop asense of what the pump shouldsound and feel like. Feel themotors and pumps. Are thereany strange noises or vibrations?Can you detect a bearing ormotor that is unusually hot? Isthere a new odor or electricalsmell?

Use caution around drivecouplings and electric controls.Don’t hurt yourself by blunderinginto something unfamiliar.

You can trace many pumpbreakdowns back to the stuffingbox. A badly leaking packinggland or mechanical seal willcause problems. Water sprayinginto a motor or bearing framewill infiltrate the pump endbearing. It will wash all lubricationfrom the bearing, causing rustand imminent failure.

If water collects under a horizontally mounted motor, the ventilation fan (which blowsonto the motor winding) willpull the water into the motor.This may cause a burned-outmotor. Water squirting up into a vertical, hollow-shaft motor of a vertical turbine pump willcause the same problems. Thesemotors are not water-cooled.

Electric motor service lifedepends on a dry, clean atmosphere.Elevate a horizontally mountedpump at least 6 inches off thefloor, and install a line to drainthe leakage away from the motor.

Vertical turbines have drain

connections in the bottom of thedischarge head. Connect these toa hose and drain the head. Keepthe drains open and flowing.

You can easily adjust thepacking gland and grease cup tothe manufacturer’s instructions.Special lubrication for the greasecup and packing is available fromlocal suppliers. The grease cuplubricates the packing and aids inpriming horizontal pumps.Whenyou add a packing ring, be sureit’s new and clean. Carefully alignthe gland without cocking it.Tighten evenly to achieve themanufacturer’s specified leakage.This means minimum leakagewith a cool stuffing box.

Replace dried and wornpacking that has lost its lubrica-tion. This requires a special toolcalled a packing hook. Packinghooks are also available fromlocal suppliers.

After removing all the packing,inspect the shaft sleeve. If thesleeve is grooved or worn, packingreplacement will have a shortlife. You need to replace the sleeve.This requires disassembling thepump. If you have a horizontalunit, take it to the shop. Verticalturbines usually require motorremoval and head shaft renewal.

If your pump is equippedwith a mechanical seal, neverallow it to run dry, even for a fewseconds. Water lubricates the sealfaces. A dry run merely bums itout. At the first sign of a leak,replace the seal. This will requiredisassembly, which a pump technician normally does. Youcan damage a new seal if youmishandle it or improperly

install it, so take care if you doyour own maintenance.

Pumping sand and silt willnaturally shorten the life of thepacking, sleeve, seals and wearrings. Good planning and siteselection can ensure maximumservice life.

If the pump is in the shop fora sleeve replacement, it’s a goodtime to measure the wear on thewear rings. If the wear is 1/32 ofan inch or .030 per side, it’s timeto restore the clearances withnew wear rings and impellerrepair. The excess wear is costingyou wasted energy (and money)through efficiency loss.

LUBRICATION

What type of lubricationshould you use and when shouldyou use it? These questions areasked repeatedly. If your motor,has Zerk grease fittings, itrequires greasing. Some of thesmaller sizes, usually 3 to 5 HPpumps, won’t have Zerk fittings.These motors have sealed bearingsand don’t require greasing.

When you add grease, be sure the grease and the fittingsare absolutely clean. The codenumber for the proper grease is EP-2. Other greases, such asmulti-purpose types, may work,but bearing manufacturers recommend only EP-2. Theexception is if the motor or pumpmanufacturer specifically recom-mends a different lubricant.

To lubricate electric motorbearings, remove the relief greaseplug. Using a hand grease gun,pump the new grease into the



56

fitting until it shows at the drain.Do this when the unit is not running so you avoid gettinggrease into the motor. I like toleave the drain plug out for a fewdays to let the excess grease workits way through the drain, notinto the motor.

The bearings will run unusu-ally hot for about 20 minutes after greasing because the bearingis purging the grease from theballs and race. As the bearing

warms up, it turns the grease to oil. It’s this mist of oil that actually lubricates the bearing.Therefore, it’s absolutely essentialto use the Code EP-2 for propermelting temperature.

Pumps mounted on bearingframes (those that have a separatemotor) are normally greasedthrough the bearing cover. Excessgrease accumulates in the largecavity of the frame. It takes years to fill the frame. Follow the manufacturer’s instructions

in the operator’s manual for greasing frequency. A drain plug is usually a pipe plug nearthe bottom of the frame.

Proper motor ventilation is just as critical as lubrication. The temperature of the motor winding determines its life.Normal temperature means a long life.

Many motors have rodentscreens installed on the vents.These are essential to keep crittersout, but they require periodiccleaning. Keep them free of lint,chaff, weeds, dirt and other debristo ensure a free, cool, air flow.

I am a believer in well ventilated shelters that protectpumping equipment and switchgear from sun and rain. Thesun’s direct rays can add 10 to 20degrees of ambient temperatureto the motor temperature. Forevery 18° Fahrenheit temperaturerise above the motor nameplaterating, the expected motor life isreduced by one-half. Thermostatcontrolled exhaust fans help keepthe inside temperature and airflow cool in pump houses.

VIBRATIONS

What does an extreme vibration signal? It could be the result of a misaligned drivecoupling or the start of bearingfailure. Some pump units canactually twist on their bases if thebase construction is too light or ifthey are not secured and groutedproperly to the foundation.

Pipeline misalignment canalso lead to vibration. Unsup-ported pipelines full of water

put a tremendous weight load onthe pump casing. Pipelines canbreak the casings if the weightload is severe enough. Thepipelines must be supported sothe pump can be removed withno stress or strain on it. I like tosee one flexible-type pipelinecoupling in either the inlet lineor discharge line.

A noise developing in apump that has otherwise beenrunning quietly usually indicatesa bearing is beginning to fail.Replace the bearing immediately.Neglect could irreparably damagethe motor or the frame.

BEARING LUBRICATION

GreaseOut

GreaseIn

ZerkFitting

Drain

PIPE SUPPORTS

Concrete with metal strap.

J bolts oranchor bolts.

Use padsbetween

piping andsupport.

This is the grease flow pattern forbearing lubrication of an electric motor.



57

A bearing that repeatedly fails indicates a possible mis-alignment or strain.Occasionally, I have found the bearing is either the wrongtype or not heavy enough for the application. If you’re indoubt, request a B-10 bearing life calculation from the pump manufacturer.

THE ELECTRIC SYSTEM

Electric switch gear needsperiodic inspection and maintenance as well as the pump and motor. This requiresan electrician who is experienced

in controls and pump starters.He should check the contacts inthe starter and replace any thatshow signs of uneven or heavypitting. If neglected, these aregoing to heat and cause high current to trip out the overloadprotection device.

If you want to burn out themotor, install overload heaterswith too high a rating or adjustthe overload trip rating up toohigh. I have actually seen amotor starter jammed shut by astick wedged against the door.The price tag for this “good idea”– a 150-HP motor rewind.

Have the electrician check andtighten each and every screw inthe panel. After several years,normal heat and temperaturechanges tend to loosen the terminalscrews. A loose connection willcause heat, burn out wiring,damage the contactor and/orcause short motor cycling andoverheating. Remember, main-taining a low temperature rise inthe electric motor will ensure along service life.

Illustration: Author.

PUMP HOUSE

Place electricalcontrol

near door

Security lock

Equipmentaccess

Proper sitedrainage

Subsurfacepiping is prefered

for protectionagainst freezing

OutflowInflow

Adequate ventilationincludes screens

and shades

Use large, concrete,thrust blocks even

on subsurface piping



60

Notes

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59

Notes



58

Notes


NPSHA = P + LH - (VP + hf)

NPSHA = P - (VP + LS + hf)

CORNELL PUMP COMPANY

CORNELL

Manufacturers of Quality Pumps Since 1946

CORNELL PUMP COMPANYP.O. Box 6334 Portland, Oregon 97228-6334

Phone: 503/653-0330 Fax: 503/653-0338

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