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Materials of ConstructionMotor Data-Design and Code Letter Designations

Motor Data-Efficiency Calculations

Useful FormulasNPSHNPSH & CavitationCavitationCorrosion - AbrasionUseful Hydraulic FormulasUseful Electrical Formulas

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1ENGINEERINGSECTION

MATERIALS OF CONSTRUCTION

PRODUCT DATA

Material CodeNo.

Material CodeNo.

MAJORCASTINGS

IMPELLERPUMP

MODEL

C 3041(SS)D 3041C 3060(SS)D 3080D 3080 (B)C/D 3085C 3102C 3126 (SS)D 3126 (SS)C 3127H 3127C 3140C 3152H 3152C 3170C 3201H 3201C 3201(SS)C 3201 (B)C 3230C 3300C 3300 (SS)C 3305C 3311C 3351C 3500C 3530C 3531C 3601C 3602

424

2,192244222222224922422222222

4104

10 or 119224426226226492242

2,42,42,42,42,42,42,4

SERIES 3000 (CP,CT,CS,DS,HS) PUMPS

789101112

Material CodeNo.

Material Material

Hardened Spheroidal Graphite IronNitril Rubber on Steel CoreAluminum BronzeNi - HardNi - ResistNoryl (fiberglass reinforced)

Aluminum AlloyCast IronSteelStainless SteelForged Spring SteelAlloyed White Iron

123456

Material CodeNo.

Materials used in Pump Construction

For more detailed information on materials of construction contact your local source of ITT Flygtproducts. In some cases, other than the standard materials listed may be available on special order.

CP, CT, CS

CP/CT/CS = Centrifugal Impeller HS = Heavy Duty Slurry DS = Vortex Impeller B = Bronze SS = Stainless Steel

DS HS

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ENGINEERINGSECTION 2

MOTOR DATA

PRODUCT DATA

Squirrel Cage Induction Motors are classified by NEMA in accordance to their locked-rotor torque, breakdown torque,slip, starting current, etc., in other words, in accordance with their design and performance characteristics, in DesignClasses B, C, and D.

NEMA also assigns a Code Letter depending on the locked rotor kVA/HP ratio measured at full voltage and ratedfrequency.

DO NOT CONFUSE THE DESIGN LETTER WITH THE CODE LETTER !

DESIGN LETTERS CODE LETTERSLetter Kilovolt-Amperes per

Designation Horsepower with Locked RotorA 0.0 - 3.14B 3.15 - 3.54C 3.55 - 3.99D 4.0 - 4.49E 4.5 - 4.99F 5.0 - 5.59G 5.6 - 6.29H 6.3 - 7.09J 7.1 - 7.99K 8.0 - 8.99L 9.0 - 9.99M 10.0 - 11.19N 11.2 - 12.49P 12.5 - 13.99R 14.0 - 15.99S 16.0 - 17.99T 18.0 - 19.99U 20.0 - 22.39V 22.4 - and up

Formulas to find the value of the NEMA Code Letter:

(3Ø) NEMA Code Letter = LRA x V x 1.732

1000 x HP

(1Ø) NEMA Code Letter = LRA x V

1000 x HP

Example: Motor 35-28-12

460 volts, 3Ø, LRA = 145, HP = 34

NEMA Code Letter = 145 x 460 x 1.732 = 3.390

1000 x 34

From code letter chart, the value of 3.398 equals Letter Designation "B".

CLASS B, most common type, has normal starting torque,low starting current. Locked-rotor torque (minimum torqueat standstill and full voltage) is not less than 100% full-loadfor 2-and 4-pole motors, 200 hp and less; 40 to 75% forlarger 2-pole motors; 50 to 125% for larger 4-pole motors.

CLASS C features high starting torque (locked-rotor over200%), low starting current. Breakdown torque not lessthan 190% full-load torque. Slip at full load is between 1-1/2 and 3%.

CLASS D have high slip, high starting torque, low startingcurrent; are used on loads with high intermittent peaks.Driven machine usually has high-inertia flywheel. At noload motor has little slip; when peak load is applied, motorslip increases.

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3ENGINEERINGSECTION

MOTOR DATA

PRODUCT DATA

Shaft Power = Rated Power

• Electrical Losses include Resistance Losses and Iron Losses.

• Mechanical Losses include Friction Losses in the Bearings and in the Mechanical Shaft Seal and Air Drag.

• Hydraulic Losses include Turbulence and Shock Losses, Internal Leakage (Back Flow) and Disk HP.

• Liquid Power Output = (Power Input) - (Electrical, Mechanical and Hydraulic Losses)

• Shaft (Rated) Power = (Power Input) - (Electrical & Mechanical Losses)

• Total Efficiency = (Liquid Power Output)(Power Input)

• Hydraulic Efficiency = (Liquid Power Output)(Shaft Power)

Mathematically:

Liquid Power Output (“Water HP”) = GPM x FT x Sp. Gr. Brake kW = l/s x m x Sp. G.3960 102.12 x Eff.

Shaft Power (HP) = GPM x FT x Sp. Gr.3960 x Hydr. Eff.

Total (Wire-to-Water) Efficiency = GPM x FT x Sp. Gr3960 x KW Input x 1.34

An Electric Submersible Pump is an integral unit of an electrical motor and a centrifugal (or propeller) pump on acommon shaft, held together by a hermetically closed (waterproof) enclosure. The motor must be strong enough tostart up and drive the impeller (propeller) across the whole Q/H performance range, keeping the temperature rise belowan established limit.

LiquidPowerOutput

HydraulicLosses

HydraulicEnd

Drive End

MotorElectrical

Losses

MechanicalLosses

Electric Power Supply

Power Input

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USEFUL FORMULAS

FORMULAS & CONVERSIONS

The Affinity Laws show how a centrifugal pump reacts to a change in either the speed or diameter of the impeller.Changes in Head, G.P.M. and Brake Horsepower caused by either speed or diameter changes are determined by thefollowing formulas. For a graphic illustration of the effect of speed changes refer to the chart below.

Note: H = Head in feet and d = Diameter.

1. Capacity Varies Directly with the Speed or Diameter:

GPM2 = GPM

1 X or GPM

2 = GPM

1 X

2. Total Head Varies Directly with the Square of the Speed or Diameter:

H2 = H

1 X

3. Brake Horsepower Varies Directly with the Cube of the Speed or Diameter:

BHP2 = BHP

1 X

( RPM2 or H 2 = H1 X

RPM1

2

) d1

( d2

2

)

( RPM1

3

)RPM2

RPM2

RPM1

d1

d2

or BHP2 = BHP

1 X ( d

2

d1

3

)

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5ENGINEERINGSECTION

NPSH & CAVITATION

PUMP ENGINEERING

NPSH can be defined as the head that causes liquid to flow through the suction piping and finally enter the eye of theimpeller.

Head that causes flow comes from either the pressure of the atmosphere or from static head plus atmospheric pressure.Atmospheric pressure is the only pressure source available to cause flow when the pump is operating under a suctionlift condition. The work that can be done, therefore, on the suction side of a pump is limited, so NPSH becomes veryimportant. There are two values of NPSH to consider.

REQUIRED NPSH is a function of the pump design. It varies between different makes of pumps, between differentpumps of the same make and varies with the capacity and speed of any one pump. This is a value that must be suppliedby the pump manufacturer.

AVAILABLE NPSH is a function of the system in which the pump operates. It can be calculated for any installation.Any pump installation, to operate successfully, must have an available NPSH equal to or greater than the requiredNPSH of the pump at the desired pump conditions.

When the source of liquid is above the pump: (As with Flygt's BS,CP,CS,DP,DS,HS type submersible pumps)

NPSH = Barometric Pressure, ft. + Static Head on suction, ft.- friction losses in suction piping, ft.- Vapor Pressure of liquid, ft.

When the source of liquid is below the pump: (As with Flygt's CT type submersible pumps)

NPSH = Barometric Pressure, ft. - Static Suction lift, ft.- friction losses in Suction piping, ft. - Vapor Pressure of liquid, ft.

Example 1.

The required NPSH of a water pump at rated capacity is 16 ft. The water temperature is 80°F. The elevation is 1000ft. above sea level. Calculated entrance and friction losses in suction piping = 3 ft. What will be the maximum suctionlift permissible?

Static Suction lift permissible = 32.9' - (3.0 + 16.0 + 1.2) = 12.7'

Losses in suction - Calculate from hydraulics of the piping system = 3'

NPSH Required = 16' Obtain from pump Manufacturer.

Vapor Pressure for 80°F from Tables = 0.51 psi x 2.35 = 1.2 ft.

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NPSH & CAVITATION

PUMP ENGINEERING

In example 2, the sum of vapor pressure + NPSH required + losses in the suction system exceed the barometricpressure,therefore, a positive head or submergence must be provided to insure uninterrupted water flow to the pump.

The principles involving NPSH apply to any type of pump. However, special attention should be taken when dealingwith centrifugal, angle, mixed-flow or propeller pumps as the suction conditions must be correct or the pump will notoperate efficiently or it may not function at all.

CAVITATION is a term used to describe a complex phenomenon that may exist in a pumping installation. In acentrifugal pump this may be explained as follows:

When a liquid flows through the suction line and enters the eye of the pump impeller an increase in velocity takes place.The increase in velocity is accompanied by a reduction in pressure. If the pressure falls below the vapor pressurecorresponding to the temperature of the liquid, the liquid will vaporize and the flowing stream will consist of liquidplus pockets of vapor. Flowing further through the impeller, the liquid reaches a region of higher pressure and thecavities of vapor collapse. It is this collapse of vapor pockets that causes the noise associated with cavitation.

Cavitation varies from very mild to very severe. A pump can operate quietly yet be cavitating mildly. The only adverseeffect might be a slight decrease in efficiency. On the other hand, severe cavitation will be very noisy and will destroythe pump impeller and/or other parts of the pump.

Example 2.

In this example we will use the same data as in example 1 except the water temperature will now be 195°F. What willbe the suction lift or head required?

Water, at 195°F, has a specific gravity of 0.96. The vapor pressure is 10.4 psi.

Note: In these examples, all heads must be in feet of head of the liquid.

Static Head Requiredat Suction Flange =(24.9 + 16.0 + 3) - 33.8 = 10.1 ft.

Vapor Pressure for 195°F fromTables = 10.4 psi x 2.39 = 24.9 ft.

Losses in suction -Calculate from hydraulics ofpiping system = 3'

NPSH Required = 16'Obtain from pump Manufacturer.

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NPSH & CAVITATION

PUMP ENGINEERING

If the pump is properly designed and installed, cavitation need not be a problem. When selecting a pump and planningthe installation, be careful to avoid the following conditions:

• Heads much lower than head at peak efficiency of pump.

• Capacity much higher than capacity at peak efficiency of pump.

• Suction lift higher or positive head lower than recommended by manufacturer.

• Liquid temperatures higher than that for which the system was originally designed.

• Speeds higher than manufacturer’s recommendation.

The above explanation of cavitation in centrifugal pumps cannot be used when dealing with propeller pumps. The waterentering the propeller pump in a large bell-mouth inlet will be guided to the smallest section, called throat, immediatelyahead of the propeller. The velocity there should not be excessive and should provide a sufficiently large capacity tofill the ports between the propeller blades. As the propeller blades are widely spaced, not much guidance can be givento the stream of water. When the head is increased beyond a safe limit, the capacity is reduced to a quantity insufficientto fill up the space between the propeller vanes. The stream of water will separate from the propeller vanes, creatinga small space where pressure is close to a perfect vacuum. In a very small fraction of a second, this small vacuum spacewill be smashed by the liquid hitting the smooth surface of the propeller vane with an enormous force which starts theprocess of surface pitting of the vane. At the same time one will hear sounds resembling rocks being thrown aroundin a barrel or a mountain stream tumbling boulders.

When selecting a propeller pump and planning the installation be careful to avoid the following conditions:

• Heads much higher than at peak efficiency of pump.

• Capacity much lower than capacity at peak efficiency of pump.

• Suction lift higher or positive head lower than recommended by manufacturer.

• Liquid temperatures higher than that for which the system was originally designed.

• Speeds higher than manufacturer’s recommendation.

Cavitation is not confined to pumping equipment alone. It also occurs in piping systems where the liquid velocity ishigh and the pressure low. Cavitation should be suspected when noise is heard in pipe lines at sudden enlargementsof the pipe cross-section, sharp bends, throttled valves or similar situations.

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Corrosion:The term “corrosion” is defined as an attack on a material through chemical or electromechanical reaction with thesurrounding medium and it can refer to the process itself or to the damage by the corrosion process. When no referenceis made to the material, it is normally understood that a metal is being attacked. The most important characteristics ofa liquid influencing corrosion are the pH factor (acidity/alkalinity), Salt Content (dissolved substances), OxygenConcentration and Temperature. If any of these characteristics deserves special attention, contact ITT Flygt’sApplication Engineering.

Abrasion:The fastest wearing part of a centrifugal pump is the impeller. Impeller wear is roughly proportional to the cube of thespeed ratio. Also, to generate a certain head, the impeller peripheral velocity must be maintained regardless of thediameter. In practical terms this means that “half the speed equals six times the life” - “half the head equals three timesthe life.” Abrasion will also be influenced by corrosion and cavitation damage. Otherwise, abrasive wear in pumps isgeneralized into three types:

Gouging abrasion, which occurs when coarse particles impinge with such force that high-impact stresses are imposed,resulting in the tearing of sizable pieces from the wearing surfaces.

Grinding abrasion, which results from the crushing action of the particles between two rubbing surfaces.

Erosion abrasion, which occurs from the impingement of free-moving particles (sometimes parallel to the surface)at high or low velocities on the wearing surface.

The pumps presented in this catalog are intended for light, “accidental” slurries only, where the presence of solids isaccidental. (A “deliberate” slurry” is a liquid/solid mixture where the main task of the pump is transporting solids).Since the required power is proportional to the Specific Gravity of the liquid, attention must be paid to the combinedSpecific Gravity of the mixture:

Where SGM = Specific Gravity of Mixture

SGL = Specific Gravity of Liquid

SGS = Specific Gravity of Solids

SC = Solids Concentration in percentage

For special materials selection or for pumping mixtures with Specific Gravity higher than 1.15, contact ITT Flygt’sApplication Engineering.

CORROSION - ABRASION

PUMP ENGINEERING

1 + S.C. ( )SGL

SGS

1

SGM

= S.G.L

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9ENGINEERINGSECTION

I. HYDRAULIC FORMULAS

1. Brake horsepower (BHP) at duty point = GPM x TDH x S.G. 3960 x pump efficiency

2. Water horsepower (WHP) = GPM x TDH 3960

3. Wire to water efficiency =

WHP x .746 or GPM x TDH or GPM x TDH kW Input Input Hp x 3960 kW Input x 5308

4. Overall efficiency = motor efficiency x pump efficiency.

5. Capacity in GPM in a discharge line is proportional to thesquare of the inside diameter.

6. For the same discharge line diameter, the friction loss headincreases approximately as the square of the velocity.

7. Net positive suction head available (NPSHA) = Ha - Hvpa + Hst - Hfs

WHERE:

Ha = Absolute pressure in feet on the surface of the liquid being pumped.This is atmospheric pressure in non-pressurized conditions.

Hvpa = Vapor pressure of the liquid being pumped in feet.

Hst = Static head in feet of the liquid level above the impeller eye.

Hfs = Suction entrance losses in feet.

USEFUL FORMULAS


( )2D1

D2

GPM1

GPM2

=

2

Hf

Hf

= ( )1V

1

V2

2

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USEFUL FORMULAS


II. ELECTRICAL FORMULAS

1. Hp = kW x 1.341 or kW = Hp x .746

2. kW input at duty point = GPM x TDH x .746 x S.G. or BHP x .746 3960 x pump eff. motor eff. Motor Eff.

3. Shaft Hp = kW input x motor eff. x 1.341.

4. Motor efficiency = BHP kW input x 1.341

5. Power factor (PF) = Real Power (Watts) Apparent Power (V.A.)

REFER TO THE FOLLOWING EQUATIONS FOR SINGLE PHASE OR THREE PHASE CURRENT.

TO FIND SINGLE PHASE THREE PHASE

6. Motor V x A x P.F. x Motor Eff. V x A x P.F. x Motor Eff. x 1.732Output 746 746(Hp)

7. Motor V x A x P.F. V x A x P.F. x 1.732Input 1000 1000(kW)

8. Amps kW Input x 1000 kW Input x 1000P.F. x V P.F. x V x 1.732

9. P.F. kW Input x 1000 kW Input x 1000A x V A x V x 1.732

10. KVA V x A or kW V x A x 1.732 or kW1000 P.F. 1000 P.F.

11. Watts V x A x P.F. V x A x P.F. x 1.732

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