Book-Hydraulics Pump Seminar
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CORNELL PUMP COMPANY EFFICIENT BY DESIGN
&
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t’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
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Table of Contents Mounting Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3 Quality Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4 Terminology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6 Fact Finding to Determine Pump Choice . . . . . . . . . . . . . . . . . . .1 3 Selecting the Pump . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1 8 Multiple Pumps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .20 Specific Speed . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .22 Affinity Laws . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .23 Pump-Engine Selection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .24 Engine Derate Guidelines . . . . . . . . . . . . . . . . . . . . . . . . . . . . .25 Average Electric Motor Life . . . . . . . . . . . . . . . . . . . . . . . . . . .26 Guide to Optimum Electric Motor Life . . . . . . . . . . . . . . . . . . . .27 Electric Motor Comparisons . . . . . . . . . . . . . . . . . . . . . . . . . . .28 Electric Control Panel Data . . . . . . . . . . . . . . . . . . . . . . . . . . . .29 Typical Auto Vacuum Prime . . . . . . . . . . . . . . . . . . . . . . . . . . .30 Materials of Construction . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3 1 B-10 Bearing Calculation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .33 Pump Performance Curves 2.5 WB . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .34 4 WB . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .35 5 WB . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .36 5 YB . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .37 4 RB . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .38 6 RB . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .39 6 RB-Various RPM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .40 4 HH . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4 1 4 x 4 x 14T . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .42 6 NHTA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .43 6 NHPP-Various RPM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .44 Specification Guide – Cornell Solids Handling Pumps . . . . . . . . . .45 Lubrication Instructions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .47 Start-up Check List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .50 Pump Troubleshooting Guide . . . . . . . . . . . . . . . . . . . . . . . . . .5 1 Air Leaks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .52 Packing, Wear Rings and Coupling Alignment . . . . . . . . . . . . . . . .53 Pump Care . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .54
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Cornell Pump Company P.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.
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Mounting Configurations
Horizontal Close-Coupled (CC). Economical, compact and efficient. Vertical Frame (VF). Driven by flexible shaft from motor above pump.
Vertical Close-Coupled (VM). This vertical style is desirable where space is limited.
Horizontal Frame (F). Driver flexibility. Base-Coupling-Guard Mounted Horizontal Frame Unit. Can be mounted with a motor or other driver on a common base.
SAE Engine Mount (EM). Ideal for remote locations or where electrical power is not available. Trailer or skid mounted.
Vertical Coupled (VC). Minimal floor space required. Standard "P" base motor used.
Redi-Prime® Run-dry, automatic dry prime and re-priming capabilities.
Cornell Pump Company • Portland, Oregon
CORNELL
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Cornell Quality Features
FULLY MACHINED IMPELLER WITH DOUBLE CURVATURE VANES
REPLACEABLE, RECESSED WEAR RINGS
EXTERNAL HYDRAULIC BALANCE LINE
BACK PULL-OUT DESIGN FOR EASE OF MAINTENANCE REPLACEABLE SHAFT SLEEVE MODULAR BEARING FRAME HEAVY, STRESS PROOF STEEL SHAFT
GENEROUSLY SIZED BEARINGS TO MAXIMIZE B-10 BEARING LIFE
LARGE, DEEP STUFFING BOX FOR EXTENDED PACKING LIFE AND MINIMUM ADJUSTMENTS (MECHANICAL SEALS OPTIONAL)
SMOOTH CONTOURED SUCTION FOR IMPROVED HYDRAULIC PERFORMANCE
RIGID, HEAVY WALLED CONSTRUCTION DOUBLE VOLUTE DESIGN STANDARD ON LARGER SIZES
CORNELL
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Cornell Pump Company • Portland, Oregon
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THE EXTERNAL HYDRAULIC BALANCE LINE Unbalanced axial forces
Holes bored in impeller
Sand and silt buildup
To lower pressure in the stuffing box (or seal chamber) and to attempt to limit the inherent axial force created by the impeller, traditional centrifugal pump designs use large holes bored through the impeller. Cornell has a more effective method –THE EXTERNAL HYDRAULIC BALANCE LINE.
Balanced axial forces Reduced Pressure Area
High pressure liquid from Sand and silt the volute passes through the Area of flushed out turbulence hub ring clearances into the CORNELL METHOD cavity between the stuffing External Hydraulic TRADITIONAL METHOD box and the impeller. Liquid Balance Line returns 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 DESIGN FEATURES 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.
Cutwater #1
As the impeller adds energy to the fluids, pressure increases around the periphery of the volute. On single volute pumps, the increasing pressure acts against the impeller area and creates unbalanced radial forces. By contrast, the Double Volute System effectively balances these forces around the impeller to reduce shaft flexure and fatigue. Cornell’s “DVS” design keeps shafts from breaking, extends the life of packing and mechanical seals, wear rings and bearings – maintaining high hydraulic efficiency.
Cutwater #2 CORNELL DOUBLE VOLUTE Radial thrust is offset and balanced by the double volute design.
Cornell Pump Company • Portland, Oregon
CORNELL
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Terminology PUMPS Pump- A mechanical device that converts mechanical forms of energy into hydraulic energy. Pump Classifications- Generally pumps can be classified into two classifications – positive displacement and centrifugal. Positive Displacement Pumps- Operate by reducing the volume of space within the pump that the liquid can occupy. In a reciprocating pump the piston forces the liquid from the cylinder into the discharge line. Centrifugal Pumps- Move liquids by increasing their speed rather than displacing or pushing them. The vanes do work on the fluid to increase the velocity without decreasing the pressure. This increased velocity is then recovered in the casing as increased pressure. TYPICAL CENTRIFUGAL PUMP IMPELLER
EXAMPLE: Reciprocating Piston Single Plunger or multiple design Diaphragm EXAMPLE: Centrifugal These can be single and multi-stage open or closed impellers
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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 a submerged suction pipe from the water surface. Usually a cause of poor pump performance when the suction pipe is not adequately submerged. Manifold- A hydraulic structure used to distribute water under pressure. Can be used to supply fluid to or receive fluid from a parallel arrangement of multiple pumps.
ELECTRICAL Volt- A unit of electrical potential. A volt is the driving force which causes a current of 1 ampere to flow through a resistance of 1 ohm.
IMPELLER EYE
In centrifugal pumps, water enters the pump and travels into the impeller through the impeller eye. In general, the larger the impeller eye, the greater the volume in gallons DISTANCE BETWEEN SHROUDS per minute.
CORNELL
Centrifugal Force- According to Websters, is that force which tends to impel a thing, or parts of a thing outward from the center of rotation.
Rotary Gear Rotary Screw Rotary Cam
Radial Flow Mixed Flow Axial Flow
Ampere- A unit of electrical current. The unit used to specify the movement of electrical charge per 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 actually available as usable power. Ohm- The practical unit to measure electrical resistance. Resistance of a circuit in which a potential difference of one volt produces a current of one ampere.
Cornell Pump Company • Portland, Oregon
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perfect vacuum is zero. Absolute pressure of the atmosphere at sea level is 14.7 psi (0 psi gauge).
point in the system assuming no friction losses or the performance of work.
Vapor Pressure- The pressure exerted when a solid or liquid is in equilibrium with its own vapor. Vapor pressure is a function of the substance and of the temperature.
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.
Vacuum- Frequently used in referring to pressures below atmospheric. Vacuum is commonly expressed in inches of mercury. 14.7 psi atmospheric pressure equivalent to 30 inches of mercury at sea level.
SUCTION SUPPLY OPEN TO ATMOSPHERE with Suction Lift
CL
Head- The vertical height of a static column of liquid corresponding to the pressure of a fluid at that point. Head can also be considered as specific work (FT. LB./LB.) necessary to increase the pressure, velocity or height of a liquid to some value.
LS PB
NPSHA = PB - (VP + LS + hf)
Potential Head- (Energy of position) The work required to elevate a weight to a certain height above some datum or reference plane. British Thermal Unit (BTU)- The amount of heat required to raise the temperature of one pound 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.
SUCTION SUPPLY OPEN TO ATMOSPHERE with Suction Head PB
Shut-off Head- Is the head generated by a pump with the discharge valve closed (pump running at zero capacity). Static Pressure Head- (Energy per pound due to pressure). The height to which liquid can be raised by a given pressure. Velocity Head- (Kinetic energy per pound). The vertical distance a liquid would have to fall to acquire 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
CORNELL
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LH
NPSHA = PB + LH - (VP + hf)
CL
Static Suction Head- When the liquid supply is above the pump. The vertical distance from the pump centerline to the surface of the liquid.
Cornell Pump Company • Portland, Oregon
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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.
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Static Discharge Head- Vertical distance from pump centerline to the free surface of the liquid in a discharge tank or point of free discharge.
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.
TOTAL STATIC HEAD STATIC DISCHARGE HEAD
CL STATIC SUCTION LIFT
LS NPSHA = P - (VP + LS + hf)
P
CLOSED SUCTION SUPPLY with Suction Lift
P
LH
CLOSED SUCTION SUPPLY with Suction Head
TOTAL STATIC HEAD STATIC DISCHARGE HEAD STATIC SUCTION HEAD
NPSHA = P + LH - (VP + hf)
Total Discharge Head- (hd) Is the sum of: (1) Static discharge head.
CL
Suction Head- (hs) exists when the liquid supply level is above the pump centerline or impeller eye. The total suction head is equal to the static height or static submergence (in feet) that the liquid supply level is above the pump centerline, less all suction line losses including entrance loss, plus any pressure (a vacuum as in a condenser hotwell being a negative pressure) existing at the suction supply source. Caution – even when the liquid supply level is above the pump centerline the equivalent of a lift will exist if the total suction line losses (and vacuum effect) exceed the positive static suction head. This condition can cause problems particularly when handling volatile or viscous liquids.
(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.
Cornell Pump Company • Portland, Oregon
CORNELL
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Work- The transference of energy by a process involving the motion of the point of application of a force, as when there is movement against a resisting force or when a body is given acceleration; it is measured by the product of the force and the displacement of its point of application in the line of action.
HYDRAULICS
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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.
3.3 FT. 2.3 FT. 1.54 FT.
Hydraulics- The study of fluids at rest or in motion. Fluid- A substance which when in static equilibrium can not sustain tangential or shear forces. This differentiates fluids from solids. However, in motion, fluids can sustain shear forces because of the property of viscosity. A fluid can be a liquid or a gas. Viscosity- The existence of internal friction or the internal resistance to relative motion of the fluid particles with respect to each other. The viscosities of most liquids vary appreciably with changes in temperature, whereas the influence of pressure change 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 as long as the temperature is constant. Example: Water or mineral oil. Thixotropic- A liquid is thixotropic if its viscosity decreases with agitation at constant temperature. Example: Glues, asphalt, greases, molasses, etc. Dilatant- A liquid is dilatant if the viscosity increases with agitation at constant temperature. Example: Clay slurries and candy compounds. Density- Density is the mass per unit volume of a substance. It is unaffected by the variations in gravity or acceleration. Specific Weight- The weight per unit volume of a substance. The two terms are frequently used interchangeably, though this is incorrect.
GASOLINE
WATER
MOLASSES
SP. GR. = 0.7 1 PSI
SP. GR. = 1.0 1 PSI
SP. GR. = 1.5 1 PSI
Pressure- The force exerted per unit area of a fluid. According to Pascal’s principle, if pressure is applied to the surface of a fluid, this pressure is transmitted undiminished in all directions. Atmospheric Pressure- The force exerted on a unit area by the weight of the atmosphere. The standard atmospheric pressure at sea level is 14.7 psi. EXAMPLE: 1 atmosphere = 14.7 psi ~ 34 feet water 34/14.7 = 2.31 psi = Head in Feet x SP.GR. 2.31 Since water weighs .0361 pounds per cubic inch, a column of water one square inch in area and one (1) foot high will weigh .433 pounds. To increase the pressure at the bottom of the column to one (1) psi requires a 2.31 foot high column of water. Gauge Pressure- Is pressure measured relative to local atmospheric pressure. Atmospheric pressure is zero gauge. Absolute Pressure- The sum of atmospheric pressure and gauge pressure. The absolute pressure in a
Cornell Pump Company • Portland, Oregon
CORNELL
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Total Head- (Formerly called Total Dynamic Head). 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 the point in the pump at which energy is added, generally, through the impeller vanes. Determined by test and dependent on pump design, pump size, and operating conditions. Net Positive Suction Head Available- The energy, above the vapor pressure of the fluid, available at the pump suction to push the fluid into the pump. Note: NPSHA depends on the system layout and must always be equal to or larger than the NPSHR. Cavitation- A result of inadequate NPSHA. When pressure in the suction line falls below vapor pressure of the liquid, vapor is formed and moves with the liquid flow. These vapor bubbles or “cavities” collapse when they reach regions of higher pressure on their way through the pump. The violent collapse of vapor bubbles forces liquid at high velocity against the metal, producing surge pressures of high intensity on small areas. These pressures can exceed the compressive strength of the metal, and actually blast out particles, giving the metal a pitted appearance. The other major effects of cavitation are drops in head, flow and efficiency. CAVITATION H–Q CUT OFF POINT
NORMAL PERFORMANCE WITH SUFFICIENT NPSHA
Pipe Friction- The system loses pressure when the water flowing through the piping encounters resistance. For example, friction occurs along the pipe walls because of roughness. Pressure loss also occurs because of turbulence induced by valves,
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Horsepower- Power delivered while doing work at the rate of 550 ft-lb per second or 33,000 ft-lb per minute, .706 BTU’s/sec. or .746 kilowatts. Hydraulic Horsepower- (Water Horsepower) The rate at which a pump adds useful energy to a fluid. Brake Horsepower- Total power required by a pump to do a specified amount of work. Brake horsepower equals Hydraulic Horsepower plus mechanical and other losses.
EFFICIENCY Of a Pump Driver- The percentage of input horsepower that is converted to usable brake horsepower by the pump driver. Of a Pump- The percentage of brake horsepower applied to the pump shaft that is converted to usable water horsepower by the pump. Bearing and seal losses are usually deducted from horsepower. Rating Curves- (Pump Curve) The most important aspect of any discussion on centrifugal pumps. A graphical representation of a pump’s performance, including NPSH requirements, horsepower requirements, etc. over its entire operating range. HEA
D–C
CAPACITY — GPM
CORNELL
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Capacity- Actual pump delivery (usually in gallons per minute in the U.S.A.).
100
CAVITATION
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fittings and changes of section. The Cornell “Condensed Hydraulic Data” book has typical pipe, valves, and fitting Head Loss Tables.
HEAD — FT.
HEAD — FT.
EFFECT ON PUMP CAPACITY
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APAC
ITY
CAPACITY — GPM
500
Cornell Pump Company • Portland, Oregon
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100 HEAD — FT.
H–
Q
ER
SEPOW
HOR BRAKE
continuously as the capacity is decreased. The rise from best efficiency point to shut-off is about 10 to 20%. Pumps with curves of this shape are used in parallel operation because of their stable characteristics. STEADY RISING H – Q
1
100
H HEAD — FT.
CAPACITY — GPM
0
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BHP
10
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500
–
• STABLE
Q
• O.K. IN PARALLEL OPERATION
H–Q GPM
1 CAPACITY — GPM
100
H–Q
HEAD — FT.
0
CAPACITY — GPM
NPSHR
25
NPSHR
0
0
500
DROOPING H – Q
H
0 500
System Curve- A graphical representation of the relationship between the Total Head and the flow rate for a given fluid system. Simple System Curve- Friction loss increases proportionally to the square of the capacity or velocity.
TYPICAL CURVES Four typical curves may be classed as follows: 1. Steady Rising Curve or a rising head capacity characteristic is a curve in which the head rises
–
Q
HEAD — FT.
BHP
2. Drooping Curve characteristic is a curve in which the head capacity developed at shutoff is less than that developed at some capacities. When pumps with drooping characteristics are run on throttling systems, operating difficulties can occur since the system friction curve can intersect the head capacity curve at two points. These pumps will also only operate in parallel when the operating point is below the shut-off head; therefore, parallel operation should be avoided with this curve shape.
FT.
EF
F
I IC
% EFF.
10
Y
C EN
BHP
HEAD — FT.
90
• GOOD PERFORMANCE • MAXIMUM Q • STABLE AT HEADS BELOW SHUT-OFF HEAD
GPM
3. Steep-Rising Curve is one where there is a large increase in head between that developed at design capacity and that developed at shut-off. It is best suited for operation where minimum capacity change is desired with pressure changes, such as batch pumping or filter systems.
Cornell Pump Company • Portland, Oregon
CORNELL
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STEEP RISING H – Q HEAD — FT.
IN GENERAL H
–
Q
• SHUT -OFF 140-150% OF BEP HEAD • STABLE
GPM
In general, it is desirable to choose
• GOOD FOR PARALLEL OPERATION
a pump to operate at maximum
• FILTER SERVICE
efficiency point or slightly to the
• SMALL Q CHANGE FOR VARIABLE HEAD
4. Flat Curve refers to a characteristic in which the head varies slightly with capacity, from shutoff to design capacity. When wide fluctuations of capacity occur with nearly constant pressure requirements this is the pump best used.
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
FLAT H – Q H–Q
HEAD — FT.
• LITTLE RISE OVER RANGE • GOOD FOR CHANGING Q WITH LITTLE HEAD CHANGE
at the end of the rating curve. If the NPSH available is sufficient to prevent cavitation, the pump will give satisfactory operation.
GPM
NOTES:
CORNELL
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Cornell Pump Company • Portland, Oregon
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Fact Finding to Determine Pump Choice In selecting a pump for a particular job, attention should be given to information gathering. Without proper and specific information, proper selection is impossible.
• 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.
It is often difficult to get information from the user because he either doesn’t know the answers or 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 in back charges for restocking and, consequently, a dissatisfied customer. IT CANNOT BE EMPHASIZED ENOUGH! YOU MUST ASK THE RIGHT QUESTIONS.
• What is the pumpage? • Is the pumpage hot? Check the NPSH. Water flashes at 212° F. Check materials of construction. Bronze expands more than iron. It’s possible that a bronze impeller might come off of a particular shaft. Check fluid viscosity. If the fluid cools off, it may thicken, and raise the horsepower requirement. • Is the pumpage cold?
Questions lead to other questions! Ask questions, even unrelated questions can help! They might trigger other questions that are very important to the 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 have been thinking of a Close-Coupled Centrifugal when the customer was thinking in terms of a Canned Turbine. • Establish a meeting of minds. • Get the facts. – Weigh them.
Check the NPSH. Ammonia boils at -28° F. Check materials of construction; extreme cold may cause embrittlement. • Is the pumpage corrosive? • What is its PH level? Above 7.0 is alkaline, below 7.0 is acidic. Check materials of construction for compatibility with pumpage. Low PH normally requires brass or stainless steel, high PH normally requires iron or stainless steel. • What is, the specific gravity of the pumpage? Acids are normally heavy, as are caustics. This means high horsepower. HQ
Then, make your selection. It may or may not be the type of equipment you first thought of! Ask WHAT the pump is SUPPOSED TO DO.
BHP H
SP GR 1.1
BHP SP GR 1.0
BHP
SP GR 0.8
• What head is required? Q
Cornell Pump Company • Portland, Oregon
CORNELL
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The following check list may help you to ask the questions needed to make the right equipment choices: 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.
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❏ 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.
WATER HQ H
VISCOUS HQ Q
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
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Cornell Pump Company • Portland, Oregon
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❏ 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, like Cornell 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
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per day. Be sure to check the capacity terms used. There is a chance for error here. 4. WHAT IS THE SUCTION CONDITION THE PUMP 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 installation of 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 compare NPSHA 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 to be washed away? - Are there cross currents creating whirlpools and/or aeration that will cause hydraulic instability in the pump?
Cornell Pump Company • Portland, Oregon
CORNELL
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❏ What about elevation? Do you know that suction lift ability decreases approximately one foot 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 have changed? 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 require much room! CORNELL
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❏ 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.
Cornell Pump Company • Portland, Oregon
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- What material should the pipe be constructed of 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?
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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:
Cornell Pump Company • Portland, Oregon
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Selecting the Pump HOW TO SELECT A CENTRIFUGAL PUMP The pump is selected after all the system data has been gathered and computed. The system TOTAL CAPACITY in gallons per minute and TOTAL HEAD in feet must be determined. You should consider suction submergence, NPSH R and A, various speeds, other drives (engine, motor, etc.) and all system condition to optimize the selection. NEEDED PRESSURE
6 AT END OF LINE
TO DETERMINE THE SYSTEM TOTAL HEAD ADD THESE FACTORS TOGETHER IN FEET.
4
DISCHARGE PIPE FRICTION
5 DISCHARGE LIFT SUCTION PIPE
1 FRICTION
2
NOTE: BE SURE TO MULTIPLY PRESSURE IN P.S.I. BY 2.31 TO CONVERT TO FEET
SUCTION LIFT
7 MISCELLANEOUS LOSSES (VALVES, ELBOWS, ETC.)
3
SUCTION ENTRANCE LOSS
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 velocity head 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).
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EXAMPLE 1: For capacity of 320 GPM, total head in feet is determined as follows:
EXAMPLE 2: For capacity of 600 GPM, total head in feet is determined as follows:
1. .28 Ft. Suction friction (6” steel pipe, 20’ long)
1.
.89 Ft.
2. 5 Ft. Suction lift
2.
5.00 Ft.
3. 2 Ft. Suction entrance loss
3.
6.90 Ft.
4. 14 Ft. Discharge friction (6” steel pipe,1000’ long)
4. 45.00 Ft.
5. 15 Ft. Discharge lift
5. 15.00 Ft.
6. 100 Ft. (43 P.S.I. x 2.31)
6. 100.00 Ft.
7. 5 Ft. Miscellaneous losses
7. 17.30 Ft.
141 Ft. Total Head
190 Ft. Total Head
Cornell Pump Company • Portland, Oregon
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SELECTING THE PUMP FOR 600 GPM @ 190 FT. T.H.
SELECTING THE PUMP FOR 320 GPM @ 141 FT. T.H.
At 3600 RPM Refer to the pump performance curve on page 35. The 4WH 40-2, 3560 RPM handles the head and capacity with 7.00” Impeller at 75% efficiency and 14 ft. NPSH required.
Refer to the pump performance curve on page 34. The 2.5 WH, 3525 RPM, handles the head and capacity with 71% efficiency. NPSH required is 11 feet. A 20 horsepower 3525 RPM motor is required with a 6.50” impeller.
At 1800 RPM Refer to the pump performance curve on page 41. The 3HA 30-4, 1775 RPM handles the head and capacity with 14” Impeller at 71% efficiency and 8 ft. NPSH required. NOTES:
DATA REQUIRED FOR MAKING A SATISFACTORY PUMP SELECTION: 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.
Cornell Pump Company • Portland, Oregon
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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 only options are to throttle the pump or vary the speed. Consequently, your pump could operate at reduced efficiency.
When you operate pumps in parallel and series, contact the pump manufacturer to ensure warrantability of the equipment for your specific application.
PUMPS IN PARALLEL 200
160
5WB
4RB
120 TDH 80
40
0
400
800
1200 GPM
1600
2000
2400
FLOW IN PARALLEL TDH (FT.) FLOW G.P.M.
Additionally, you can service or repair multiple units during low demand periods to avoid total system shut-downs. Often two small pumps have lower NPSHR characteristics than one large pump. When you shop for multiple pump systems, it usually is important to choose pumps with a curve shape that continually rises as the flow reduces.
INCREASED FLOW
190
180
170 160
140
120
100
90
200 700 1010 1200 1360
4RB 40-4 12.5" 5WB 40-2 7"
200
540
660 760
TOTAL IN PARALLEL
880
970 1050 1080
200
540
860 1460 1890 2170 2410
PUMPS IN PARALLEL More than one unit pumping into a common discharge manifold (increases capacity, maintains head).
Suction Common discharge
Suction
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NOTE: The diagram on this page is intended to show the parallel concept. It is not intended to show proper system design (no valves) or installation of parallel operation.
Cornell Pump Company • Portland, Oregon
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INCREASED HEAD PUMPS IN SERIES 400
PUMPS IN SERIES 300
The discharge of the first stage is piped into the suction of the second stage (maintains flow, increases head).
TDH 200
5WB 4RB
100
0
200
400
600 GPM
800
1000
1200
HEAD IN SERIES 200
400
600
800 1000 1200
4RB 40-4 12.5" 171
170
168
163
155
141
5WB 40-2 7"
192
190
186
175
154
113
TOTAL IN SERIES
363
360
354
338
309
254
TDH (FT.)
G.P.M.
0
120
NOTES:
NOTE: The diagram above is intended to show the series concept. It is not intended to show proper system design (no valves) or installation of series operation.
Cornell Pump Company • Portland, Oregon
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Specific Speed (NS) The speed at which an impeller would run if it were proportionally reduced in size so as to deliver 1 GPM against a total dynamic head of 1ft. Specific Speed is a characteristic number which has a great deal of meaning to a pump designer. The intent of this description, however, is not to delve into any theoretical discussion, but to give us exposure to the concept, define what specific speed is, and show how it can have a practical meaning to us in our day to day work with pumps. Specific speed is best defined by its formula: NS =
n
Q
H 3/4
where: n = Revolutions per minute Q = B.E.P. Capacity in GPM at Maximum Impeller Diameter H = 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 to 4,000 refer to radial flow type impellers; specific speeds from approximately 4,000 to 10,000 refer to mixed flow type impellers and specific speeds above 10,000 are usually axial flow type impellers. Generally, you can predict the possible efficiency of a pump if you know its capacity at B E.P. and the specific speed. Suction Specific Speed (S) is a parameter, or index of hydraulic design but here it is essentially an index descriptive of the suction capabilities and characteristics of a given first stage impeller.* It is expressed as: S=
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RPM
GPM
where:
RPM = pump speed GPM = 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 between 3,000 and 20,000 depending on impeller design, speed, capacity, nature of liquid, conditions of service and degree of cavitation. Cameron Hydraulic Data Indicates: A high suction specific speed may indicate the impeller eye is somewhat larger than normal and consequently the efficiency may be compromised to obtain a low NPSHR. Higher values of S may also require special designs and may operate with some degree of cavitation. To avoid marginal designs on the suction side it is desirable for the user or systems engineer to consult with the Pump Manufacturer for suggested design, criteria, and to make certain that the suction conditions finally established will meet the requirements of the pump selected.
RADIAL
500
FRANCIS
1000
NS=
2000
MIXED FLOW
3000 4000 5000
AXIAL
10,000
15,000
R.P.M. G.P.M. H 3/4
CENTRIFUGAL
MIXED FLOW
PROPELLER
APPROXIMATE SPECIFIC SPEED TO IMPELLER SHAPE
(NPSHR) 3/4
Cornell Pump Company • Portland, Oregon
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Affinity Laws AFFINITY RELATIONSHIP EXAMPLE
The affinity laws express the mathematical relationship between the several variables involved in pump performance. They apply to all types of centrifugal and axial flow pumps. They are as follows:
Cornell Model 6RB 13.5” diameter impeller reference speed – 1780 RPM. Proposed operational speed – 2200 RPM.
1. With impeller diameter held constant:
Speed ratio:
A.
Q1 Q2
B.
H1 H2
C.
=
=
BHP1 BHP2
D.
NPSHR1 NPSHR2
Q= H= BHP = N=
N1
2200 RPM
N2
1780 RPM 2
( ) ( ) ( ) N1
Affinity laws: Q1 x 1.236 = Q2 H1 X (1.236)2 = H2 BHP1 X (1.236)3 = BHP2
N2
N1
=
3
REFERENCE POINT ON 1780 RPM PERFORMANCE CURVE:
N2
N1
=
2*
N2
Capacity, GPM Total Head, Feet Brake Horsepower Pump Speed, RPM
Q1 Q2
B.
H1 H2
C.
BHP1 BHP2
D1
=
=
3000 GPM @ 150’ TDH @ 89% EFF. @ 14’ NPSHR HP1 =
3000 GPM x 150' TDH
= 127.7 HP
3960 x .89 EFF.
PERFORMANCE AT 2200 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. A.
= 1.236
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
D2 2
( ) ( )
=
Q2 = Q1 x 1.236 = 3000 GPM x 1.236 = 3708 GPM
D1 D2
D1 D2
3
*Note: NPSHR2 ~ 22’. NPSHR does not change exactly as the square of the speed ratio, but this is conservative for speed increases. If speed is being reduced, use the first power of the speed ratio. Refer to factory. Note: Actual operating conditions depend on the system requirements.
Cornell Pump Company • Portland, Oregon
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Pump Engine Selection 3000 GPM @ 155’ TDH CORNELL MODEL 6RB SPEED RANGE 1800 – 2200 RPM 89% PUMP EFFICIENCY BRAKE HORSEPOWER REQUIRED:
ACTUAL PUMPING ENVIRONMENT: 2500’ Elevation 30% Relative Humidity 115° F TOTAL HORSEPOWER REQUIRED:
3960 x .89
Pump Requirement Service Factor – 10% Temp./Humidity Correction – 3% Elevation Correction – 6%
132.0 HP 13.2 4.0 7.9
PERFORMANCE CURVE BASED ON: 500’ Elevation 29.38” HG 85° F
TOTAL NET CONTINUOUS HP REQUIRED
163.7 HP
3000 GPM x 155' TDH
= 132 HP
NOTES:
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Cornell Pump Company • Portland, Oregon
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Engine Derate Guidelines 1. For every 10° F above rated temperature, derate engine 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.
10” Stromag torque limitations – 362 FT-LBS. DIESEL FUEL: GASOLINE:
WT. 7.1 LBS/GAL WT. 5.9 LBS/GAL
TORQUE (FT-LBS) =
5250 x HORSEPOWER RPM
3. Fan/Flywheel losses – 5-6%. 4. Service factor – 10% (allows for engine wear).
3306T PERFORMANCE CURVES
500
2 3
650
950 684 C
850
600
N-M
550
700 1
TORQUE LB – FT
600
750
550
450 RATING CURVES
400 280
200
260 A
190
365
170
375
1
150
380
2
130
3
110 1400
1600
1800
2000
ENGINE RPM
2200
160
200 140 B 120
160 140
100 FUEL CONSUMPTION
0.45
260
0.40 220
0.35 1400
1600
1800
2000
G/KW/H
210
220
180
BSFC LB/BHP-H
230
B.S.F.C. (LB/BHP-HR)
180 KW
BHP
240
HORSE POWER
TORQUE (FT. LBS)
MODEL 685T
2200
ENGINE SPEED - RPM
Cornell Pump Company • Portland, Oregon
CORNELL
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Average Electric Motor Life HP RANGE
AVERAGE LIFE (YR)
LIFE RANGE (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.
MOTOR FAILURE SURVEY BY A LARGE SERVICE SHOP* CAUSE OF FAILURE
TOTAL FAILURE (%)
Overload (overheating)
27
Normal insulation deterioration (old age)
5
Single phasing
10
Bearing failures
12
Contamination Moisture
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.
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Cornell Pump Company • Portland, Oregon
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Guide to Optimum Electric Motor Life EXTENDING THE LIFE OF THE INSULATION SYSTEM 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% temperature increase. 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 6000 FT 10000 FT
1.15 SF 1.10 SF 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).
NOTES:
Cornell Pump Company • Portland, Oregon
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Electric Motor Comparisons UNIT ENERGY SAVING IN DOLLARS PER HORSEPOWER* Higher Efficiency Lower Efficiency 70 72 74 76 78 80 82
72
74
76
78
80
0.296 0.576 0.841 1.093 0.280 0.545 0.797 0.265 0.517 0.252
1.332 1.036 0.756 0.491 0.239
82
1.264 0.984 0.718 0.467 0.227
84
85
86
87
88
89
1.200 0.935 0.683 0.788 0.444 0.549 0.65 0.750 0.217 0.321 0.423 0.523 0.620 0.716
Higher Efficiency 85 84 85 86 87 88 89 90
86
87
88
0.704 0.207 0.306 0.404 0.102 0.202 0.299 0.100 0.197 0.197
89
90
0.499 0.394 0.292 0.193 0.095
0.592 0.488 0.385 0.286 0.188 0.093
91 0.683 0.579 0.477 0.377 0.279 0.184 0.091
92
93
94
94.5
95
0.772 0.700 0.566 0.466 0.369 0.273 0.180
0.755 0.653 0.553 0.456 0.361 0.267
0.738 0.639 0.541 0.585 0.625 0.446 0.488 0.529 0.353 0.395 0.436
Higher Efficiency 91 90.5 91.0 91.5 92.0 92.5 93.0 93.5
91.5
92
92.5
0.045 0.090 0.134 0.178 0.045 0.089 0.133 0.044 0.088 0.044
93
93.5
94
94.5
95
95.5
96
0.222 0.176 0.132 0.087 0.043
0.264 0.219 0.174 0.130 0.086 0.043
0.307 0.262 0.217 0.173 0.129 0.085 0.042
0.349 0.304 0.259 0.215 0.171 0.127 0.084
0.345 0.300 0.256 0.212 0.169 0.126
0.341 0.297 0.253 0.210 0.167
0.338 0.294 0.334 0.251 0.291 0.208 0.248
*Based on 1000-hr/yr operation and 1.0¢/kWh power costs.
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Cornell Pump Company • Portland, Oregon
96.5
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Electric Control Panel Data AUTOTRANSFORMER STARTER TYPE AT
STAR-DELTA STARTER TYPE SD
PART WINDING STARTER TYPE PW
PRIMARY REACTOR STARTER TYPE PR
REACTOR STARTER TYPE R
Can be used with any standard squirrel cage motor.
Requires a special motor with 6 leads brought out (Delta wound stator).
Requires a special motor in which the stator windings are divided into two or more equal parts with six leads provided. Also dual-voltage motors can be used on the lower range.
Can be used with any standard squirrel cage motor.
Can be used with any standard squirrel cage motor.
The motor is connected to the line through the reduced voltage taps of an auto transformer for the starting interval and then directly across the line for running condition.
This method requires two main or line contactors to connect the motor winding in delta connection for running. A third contactor is used to form the star point on the starting step.
Like the star-delta starter, this starter requires no external equipment. One winding is connected to the line for starting. After a time interval the second or run contactor connects the other motor winding to the line in parallel with the first winding.
A high resistance is connected in series with the motor on starting and after a time interval this resistance is shortcircuited and motor is connected directly to the line.
The motor is connected to the line through the reduced voltage taps of a reactor for the starting interval and then directly across the line for running condition.
auto-transformer taps at: 80-65-50%
100%
Current 64 42 25% Torque 64 42 25%
33% 33%
ADVANTAGES
High torque efficiency. All the power taken from the line, except for transformer losses, is transmitted to the motor. Starting current and torque are easily adjusted by changing auto-transformer taps. Closed circuit transition.
The star-delta starter provides low in-rush current with high torque efficiency, without the use of any external equipment. Normally open circuit transition but closed transition can be achieved with the use of resistors
Part-winding starting provides one-step acceleration at a reduced current. So that the second current in-rush is not objectionable. Closed circuit transition.
This type provides almost as smooth starting as the reactor type starter. The current becomes lower and the voltage at the motor terminals rises as the motor accelerates. Closed circuit transition.
This type provides the smoothest starting of all reduced voltage starting methods. More suitable for jogging or inching service. Closed circuit transition.
LIMITATIONS
Torque remains practically constant for the first step and practically consistent at another value for the second step.
Starting characteristics depend on motor design and cannot be adjusted. Requires special delta wound motor.
Requires special motor or dual-voltage motor on low range. Torque efficiency is usually poor for high speed motors.
Unavoidable power loss in resistor. Low torque efficiency. Duty cycle limited by thermal capacity of resistor.
Taps must be selected on job site to obtain starting voltage level suitable for the load.
Low starting torque applications.
APPLICATIONS
Applications where there are limitations on starting voltage and current. Most widely used.
Commercial air conditioning equipment.
Geared or belted drives, and other delicate applications.
Textile machinery, and other driven loads requiring smooth, shockless starting.
APPROX. PRICE COMPARISON (% OF TYPE AT)
100%
MOTOR REQUIREMENTS
DESCRIPTION OF OPERATION
STARTING CHARACTERISTICS IN PERCENT OF NORMAL
100%
60%
Line voltage 60% 45%
40%
80
65%
80 64
65% 42%
More than 100%
Cornell Pump Company • Portland, Oregon
Variable with tape setting and load.
More than 100%
CORNELL
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Dry Prime Methods VACUUM PUMP ENCLOSURE (OPTIONAL) (VP-S UNIT) AUTO PRIMING SENSOR
SELECTRIC VACUUM PRIME CONTROL PANEL
6
10
11
11
7
8
9
5
TYPICAL AUTO VACUUM PRIME
4 HOSE
VALVE
4 DIA. MIN.
12
4" TO 6"
3 2
12
1
12
KEY 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
2
CORNELL REDI-PRIME® WITH RUN-DRY™ OPTION
10 5
6
4 7
1
8 9
4 DIA. MIN.
3 4" TO 6"
11
11
KEY 11
CORNELL
30
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
Cornell Pump Company • Portland, Oregon
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Materials of Construction CLEAR LIQUID PUMPS SERIES W, Y, R AND H Standard Material Standard of Construction High Hot Oil Cast Iron All Iron Construction Pressure Bronze Fitted
Parts Volute Casing Wear Rings Impeller Impeller Washer Impeller Key Impeller Screw Suction Cover or 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
Abrasion Resistant
Stainless Steel
Steel Bronze SC CI SC
BZ BA BZ
CI BA BZ
CI
CI
CP BA BZ
CA SG CA
ST
ST
ST
ST
ST
SS
KS
KS
KS
KS
KS
SA
SD
SD
SD
SD
SD
SD
SD
SD
CI
CI
CI
CP
CA
SE
SC
BA/BZ
CI
CI
CI
CI
CI
BA
SG
SS
BA
CI
BZ
BA
**
SS
SS C I/SS
SE
**
SE
CI C I or ZK SD
CI
CI
CI
SD
SD
SD
SD
PK TE SS SM SB
SD Consult Factory
SD
PK TE BA SM BP
TE BA SM BP
TE SS SM
TE
TE SS SE
TE BA SE
SB
SB
SB
SY
Frame shafts are SP; ** Close-coupled shafts are SA
SM SB
SB
SB
VF Motor Stand Base Elbow Base Elbow Stand
CI
SE
SE SY
Primer Paint
Red Oxide Alkyd Acrylic Enamel
Fab. steel or C I
MATERIAL CODES PK Graphited Acrylic
SM SAE Grade 5
SA Steel AISI 1045 SB Annealed Steel Tubing
SP Stress Proof Equal MOD. SAE 1144 SS Stainless Steel AISI 416
CA Ductile Iron Nodular NI-QT H.T. to 400-500 BHN
SC Cast Steel AISI 1030, ASTM A216
ST Stainless Steel AISI 416 H.T. to 300-325 BHN
Cl
SD Stainless Steel AISI 302, 303, 304
SY Annealed 304/316 Stainless Steel Tubing
CP Ductile Iron ASTM A536-72 NOD-1B
SE Stainless Steel AISI 316, ASTM A296-CF8M
TE Glass-filled Teflon
KS Keystock AISI C1018
SG Stainless Steel H.T. to 400-500 BHN
ZK Zamak-3 or equivalent
BA Bronze (SAE 660) ASTM B144-3B C93200 BP Copper Tubing BZ Bronze (SAE 40) ASTM B584 C83600
Cast Iron ASTM A48, Class 30
Note: Special Materials of Construction are available. Consult factory.
Cornell Pump Company • Portland, Oregon
CORNELL
31
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Materials of Construction SOLIDS HANDLING PUMPS SERIES NL, NN, NH, NON-CLOG, DELTA, NAUTILUS AND FOOD HANDLING PUMPS Standard Standard Standard Food Non-Clog Material 3HM and High Abrasion Stainless Nautilus Handling of Construction Construction Construction Pressure Resistant Steel All Iron
Parts Volute Casing Wear Rings Impeller Impeller Washer Impeller Key Impeller Screw Suction Cover or Backplate Bracket, Frame Shaft Shaft Sleeve Seal Gland Packing Gland Packing Studs Packing Lantern Ring
CI
CI ST
CP ST
KS
KS
SD
SD
CI
SD
CP
CI
CI
CI SS
**
SS
SS
CI
Fasteners
CA SG CA
CP
CI
ST
SD
SD
SD
SD
CP
CA
SE
SC
BA/BZ
CI
CI
CI
CI
CI
SS
SG
SS
BA
CI
BZ
SD SD Consult Factory
SD
CI
SD
SD
SD
SD
PK TE SM
PB TE SM
TE SM
VF Motor Stand Base Elbow Base Elbow Stand
BZ BA BZ
SD
CI
Frame shafts are SP; ** Close-coupled shafts are SA
SC CI SC
ST KS
CI
SM
Bronze
ST KS
CI
SSSM
SE
Steel
KS
** SE
TE SE Primer Paint
CI
TE SE
Fab. steel or C I
BZ Bronze (SAE 40) ASTM B584 C83600 CA Ductile Iron Nodular NI-QT H.T. to 400-500 BHN Cl
Cast Iron ASTM A48, Class 30
PB Acrylic Packing
SM SAE Grade 5
PK Graphited Acrylic
SP Stress Proof Equal MOD. SAE 1144
SA Steel AISI 1045 SC Cast Steel AISI 1030, ASTM A216 SD Stainless Steel AISI 302, 303, 304
SS
Stainless Steel AISI 416
ST Stainless Steel AISI 416 H.T. to 300-325 BHN TE Glass-filled Teflon
CP Ductile Iron ASTM A536-72 GR. 65-45-12 NOD-1B KS Keystock AISI C1018
SE Stainless Steel AISI 316, ASTM A296-CF8M
ZK Zamak-3 or equivalent
SG Stainless Steel H.T. to 400-500 BHN (SG double wear rings have minimum 50 BHN difference)
Note: Special Materials of Construction are available. Consult factory.
CORNELL
32
TE SE
Red Oxide Alkyd Acrylic Enamel
MATERIAL CODES BA Bronze (SAE 660) ASTM B144-3B C93200
SE
Cornell Pump Company • Portland, Oregon
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B-10 Bearing Life Calculations PUMP ASSEMBLY 4 x 4 x 14T VC18DB Vertical
SEAL
VOLUTE TYPE
SLEEVE
Single
Single
A11535 3.00" O.D.
DESIGN POINTS IMPELLER DIAMETER
RPM
SUCTION HEAD
DIFF. HEAD
GPM
% EFF.
HP
SPECIFIC GRAVITY
BEP
13.56"
1760
0 ft
200 ft
420
58.0
37
1.00
1300
THRUST @ IMPELLER AXIAL
1233-lb.
RADIAL
667-lb.
IMPELLER WT.
TOTAL 1303.9-lb.
70.74176 667.5-lb.
FRAME BEARINGS BEARING NO.
Opp. Pump End D7316 DEFLECTION @ SUCTION WEAR RING Axial & Radial
Pump End 6316 Radial Only
THRUST B10 LIFE HRS.
SHAFT: B3172, STRESS PROOF
59,189
236,729
.0071-in.
FATIGUE SAFETY FACTORS @ Sleeve Shoulder
@ Hub
6.33
5.46
FATIGUE STRESS DETAILS BENDING
TENSION
SHEAR
TORSIONAL SHEAR
COMBINED FATIGUE
@ SLEEVE SHOULDER
6000
6247
5573
645
15,785
@ HUB SHOULDER
5573
9308
212
1259
18,328
Cornell Pump Company • Portland, Oregon
CORNELL
33
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Model 2.5WH: 3600 RPM-60 Hertz Solids Dia.
Speed
Impeller Dia.
3525
VARIOUS ENCLOSED
Style
.50"
SINGLE VOLUTE
NS
Suction
1357
3"
Discharge
No. vanes
2.5"
5
MOUNTING CONFIG.: CC, VM, F, VF, EM, VC
80
FEET
METERS
Clear Liquid Pump
70
50
P 40
30
200
12 FT. (3.7 M) 65 68 72 18 FT. (5.5 M) 76 79
60
7.5" DIA.
225
TOTAL DYNAMIC HEAD
60
E R F O R M A N C E
8 FT. (2.4 M)
250
7" DIA. 76
175 6.5" DIA.
25 FT. (7.6 M) NPSH REQUIRED 72
150
68 6" DIA.
65
125
60
5.5" DIA.
30 HP
100 25 HP
75
20 20 HP
50
15 HP 10 HP
10 25 0
C
0
U R V E S
100
200
300
400
500
600
CAPACITY 25
50
75
100
U.S. GALLONS PER MINUTE 125 CUBIC METERS PER HOUR
MAXIMUM IMPELLER DIAMETER HP
FOR FULL MOTOR LOAD
FOR FULL MOTOR LOAD PLUS 15% S.F.
20
A (7.0")
15
B (6.44")
B+ (6.88")
10
C (5.50")
C+ (5.88")
7.5
D (4.88")
D+ (5.31")
Feet x .305 = Meters Inches x 25.4 = Millimeters GPM x .227 = Cubic Meters/Hour GPM x 3.785 = Liters/Minute HP x .746 = KW 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.
CORNELL
34
Cornell Pump Company • Portland, Oregon
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Model 4WH: 3600 RPM-60 Hertz Solids Dia.
Speed
Impeller Dia.
3560
VARIOUS ENCLOSED
Style
1.19"
SINGLE VOLUTE
NS
Suction
2107
5"
Discharge
No. vanes
4"
5
MOUNTING CONFIG.: CC, VM, F, VF, EM, VC
FEET
METERS
Clear Liquid Pump
70
50
40
30
15 FT. (4.6 M)
225
TOTAL DYNAMIC HEAD
60
12 FT. (3.7 M)
7.06" DIA.
60
70
75
200
79
20 FT. (6.1 M)
81
6.5" DIA. 175
81 79
6" DIA.
150
75
P
70
5.5" DIA.
125
25 FT. (7.6 M) NPSH REQUIRED
E R F O R M A N C E
60 5" DIA.
100
50 HP 75
20 40 HP
50
30 HP
10 25
15 HP
20 HP 25 HP
0 0
200
400
600
800
CAPACITY 50
100
150
200
C
1200 1400 U.S. GALLONS PER MINUTE
1000
250
U R V E S
300 CUBIC METERS PER HOUR
MAXIMUM IMPELLER DIAMETER HP
FOR FULL MOTOR LOAD
FOR FULL MOTOR LOAD PLUS 15% S.F.
50
7.06"
40
6.62"
7.00"
30
6.25"
6.44"
25
5.88"
6.12"
20
5.50"
5.81"
15
5.00"
5.38"
Feet x .305 = Meters Inches x 25.4 = Millimeters GPM x .227 = Cubic Meters/Hour GPM x 3.785 = Liters/Minute HP x .746 = KW 1/11/06
Performances shown are for Cool Water, Close-Coupled Electric configuration with Packing. Other mounting styles or liquids may require horsepower and/or performance adjustments.
Cornell Pump Company • Portland, Oregon
CORNELL
35
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Model 5WB: 3600 RPM-60 Hertz Solids Dia.
Speed
Impeller Dia.
3560
VARIOUS ENCLOSED
Style
.97"
SINGLE VOLUTE
NS
Suction
1821
6"
Clear Liquid Pump
FEET
METERS
16 FT. (4.9 M) 50
300 8.31" DIA.
60
70
22 FT. (6.7 M) 75
275 8" DIA.
E R F O R M A N C E
50
40
30
TOTAL DYNAMIC HEAD
60
P
6
MOUNTING CONFIG.: CC, VM, F, VF, EM, VC
28 FT. (8.5 M) NPSH REQUIRED
79
80
70
No. vanes
5"
13 FT. (4.0 M)
90
Discharge
250
79 7.5" DIA.
225 75 200 7" DIA. 175
100 HP
70
150 75 HP 125
60 60 HP
100
50 HP 75
40 HP
20 50
C
0
U R V E S
200
400
600
800
1000
1200 1400 U.S. GALLONS PER MINUTE
CAPACITY 50
100
150
200
250
300
350
CUBIC METERS PER HOUR MAXIMUM IMPELLER DIAMETER HP
FOR FULL MOTOR LOAD
FOR FULL MOTOR LOAD PLUS 15% S.F.
100
8.31"
75
8.19"
8.31"
60
7.62"
8.00"
50
7.25"
7.56"
40
6.75"
7.12"
Feet x .305 = Meters Inches x 25.4 = Millimeters GPM x .227 = Cubic Meters/Hour GPM x 3.785 = Liters/Minute HP x .746 = KW
Performances shown are for Cool Water, Close-Coupled Electric configuration with Packing. Other mounting styles or liquids may require horsepower and/or performance adjustments.
CORNELL
36
Cornell Pump Company • Portland, Oregon
7/25/00
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Model 5YB: 3600 RPM-60 Hertz Solids Dia.
Speed
Impeller Dia.
3560
VARIOUS ENCLOSED
Style
.62"
DOUBLE VOLUTE
NS
Suction
1505
8"
No. vanes
Discharge
5"
6
MOUNTING CONFIG.: CC, VM, F, VF, EM, VC
FEET
METERS
Clear Liquid Pump
140
450 10.09" DIA.
120
400
15 FT. (4.6 M) NPSH REQUIRED 16 FT. (4.9 M) 70 20 FT. (6.1 M) 75 80 82 28 FT. (8.5 M) 84 30 FT. (9.1 M) 84
60
100
80
60
TOTAL DYNAMIC HEAD
10" DIA.
350 300
82
9" DIA.
80
8" DIA.
P
150 HP
250
E R F O R M A N C E
75 7.5" DIA.
125 HP
200 70
60 HP
150
100 HP
40 75 HP
100 20 50 0 200
0
400
600
800
CAPACITY 50
100
150
200
C
1600 1200 1400 U.S. GALLONS PER MINUTE
1000
250
300
U R V E S
350
CUBIC METERS PER HOUR MAXIMUM IMPELLER DIAMETER HP
FOR FULL MOTOR LOAD
FOR FULL MOTOR LOAD PLUS 15% S.F.
200
10.09"
150
9.81"
10.09"
125
9.31"
9.62"
100
8.62"
9.06"
75
7.88"
8.25"
Feet x .305 = Meters Inches x 25.4 = Millimeters GPM x .227 = Cubic Meters/Hour GPM x 3.785 = Liters/Minute HP x .746 = KW 7/25/00
Performances shown are for Cool Water, Close-Coupled Electric configuration with Packing. Other mounting styles or liquids may require horsepower and/or performance adjustments.
Cornell Pump Company • Portland, Oregon
CORNELL
37
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Model 4RB: 1800 RPM-60 Hertz Solids Dia.
Speed
Impeller Dia.
1775
VARIOUS ENCLOSED
Style
.84"
SINGLE VOLUTE
NS
Suction
1332
6"
Discharge
No. vanes
4"
7
MOUNTING CONFIG.: CC, VM, F, VF, EM, VC
FEET 60
50
40
30
P E R F O R M A N C E
20
TOTAL DYNAMIC HEAD
METERS
Clear Liquid Pump 8 FT. (2.4 M) 200
10 FT. (3.0 M)
12.75" DIA.
60
70
175
75
15 FT. (4.6 M)
80
83
12" DIA.
85
150
85
83
11" DIA.
80
125 10" DIA. 100
75
9" DIA.
75 8" DIA.
30 HP 25 HP
10
20 HP
25
15 HP 10 HP
0
0
U R V E S
50 HP 70 40 HP
50
C
20 FT. (6.0 M) NPSH REQUIRED
200
400
600
800
1200 1400 U.S. GALLONS PER MINUTE
1000
CAPACITY 50
100
150
200
250
300
350
CUBIC METERS PER HOUR MAXIMUM IMPELLER DIAMETER HP
FOR FULL MOTOR LOAD
FOR FULL MOTOR LOAD PLUS 15% S.F.
50
12.75"
40
11.88"
12.62"
30
10.88"
11.38"
25
10.38"
10.75"
20
9.69"
10.12"
15
8.88"
9.25"
10
7.75"
8.25"
Feet x .305 = Meters Inches x 25.4 = Millimeters GPM x .227 = Cubic Meters/Hour GPM x 3.785 = Liters/Minute HP x .746 = KW 6/99
Performances shown are for Cool Water, Close-Coupled Electric configuration with Packing. Other mounting styles or liquids may require horsepower and/or performance adjustments. CORNELL
38
Cornell Pump Company • Portland, Oregon
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Model 6RB: 1800 RPM-60 Hertz Solids Dia.
Speed
Impeller Dia.
1780
VARIOUS ENCLOSED
Style
NS
1.31"
DOUBLE VOLUTE
2209
Suction
No. vanes
Discharge
10"
6"
6
MOUNTING CONFIG.: CC, VM, F, VF, EM, VC
80
FEET
METERS
Clear Liquid Pump
70
50
40
30
225
TOTAL DYNAMIC HEAD
60
250
12 FT.(3.7 M.)
200 13.5" DIA . 175
75
80
13" DIA.
85 87
15 FT.(4.6 M.)
89
18 FT.(5.5 M.) NPSH REQUIRED
150 12" DIA.
89 87
125 11" DIA.
P 85
E R F O R M A N C E
80 75
100 125 HP
75
20 100 HP
50
75 HP
10 25
60 HP
0 0
500
1000
1500
2000
2500
CAPACITY 100
200
300
400
500
600
C
3000 3500 4000 U.S. GALLONS PER MINUTE 700
800
U R V E S
900
CUBIC METERS PER HOUR MAXIMUM IMPELLER DIAMETER HP
FOR FULL MOTOR LOAD
FOR FULL MOTOR LOAD PLUS 15% S.F.
125
13.31"
13.50"
100
12.50"
13.00"
75
11.62"
12.00"
60
11.06"
11.50"
Feet x .305 = Meters Inches x 25.4 = Millimeters GPM x .227 = Cubic Meters/Hour GPM x 3.785 = Liters/Minute HP x .746 = KW 1/00
Performances shown are for Cool Water, Close-Coupled Electric configuration with Packing. Other mounting styles or liquids may require horsepower and/or performance adjustments.
Cornell Pump Company • Portland, Oregon
CORNELL
39
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Model 6RB: Various RPM-60 Hertz Impeller Dia.
Speed
Solids Dia.
Style
VARIOUS ENCLOSED
VARIOUS
1.31"
DOUBLE VOLUTE
100
FEET
METERS
HQ A
TRIM 13.50"
E R F O R M A N C E
60
50
40
30
TOTAL DYNAMIC HEAD
70
P
10"
6"
6
MOUNTING CONFIG.: CC, VM, F, VF, EM, VC
RPM 2200
HQ B
TRIM 13.50" 12.50"
8 FT.(2.4 M.) 50 60
A
80
2209
No. vanes
Discharge
RPM 2000 2200
HQ C
TRIM 13.50" 12.38" 11.62"
RPM 1800 2000 2200
HQ D
RPM 1600 1800 2000
TRIM 13.50" 12.25" 11.38"
FULL DIAMETER
325 300
90
Suction
NS
80
275
85
15 FT.(4.6 M.) 89
B
250
Clear Liquid Pump
13 FT.(4.0 M.)
70
13.50"
23FT.(7.0 M.) NPSH REQUIRED 89
225
250 HP
C 200 175
D
200 HP
150 125
150 HP
125 HP 100 HP
100 75
C
0
U R V E S
500
1000
1500
2000
2500
CAPACITY 100
200
300
400
500
600
3000 3500 4000 U.S. GALLONS PER MINUTE 700
800
900
CUBIC METERS PER HOUR Feet x .305 = Meters Inches x 25.4 = Millimeters GPM x .227 = Cubic Meters/Hour GPM x 3.785 = Liters/Minute HP x .746 = KW 9/99
HP, efficiency and NPSHR are for full diameter impellers only and may vary somewhat for less than full diameter impellers. Performances shown are for Cool Water, Close-Coupled Electric configuration with Packing. Other mounting styles or liquids may require horsepower and/or performance adjustments.
CORNELL
40
Cornell Pump Company • Portland, Oregon
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Model 3HA: 1800 RPM-60 Hertz Solids Dia.
Speed
Impeller Dia.
1775
VARIOUS ENCLOSED
Style
.50"
SINGLE VOLUTE
NS
Suction
800
6"
No. vanes
Discharge
3"
6
MOUNTING CONFIG.: CC, VM, F, VF, EM, VC
FEET
METERS
Clear Liquid Pump 5 FT.(1.5 M.) 60
275 250
50
40
30
TOTAL DYNAMIC HEAD
70
60
65
15.22" DIA.
80
225
6 FT.(1.8 M.) NPSH REQUIRED 70 71
15" DIA.
8 FT.(2.4 M.) 71
14" DIA.
70
200
60 HP
13" DIA.
175
50 HP
P
12" DIA.
E R F O R M A N C E
40 HP
150
11" DIA. 125
30 HP 25 HP
100
20 HP 75 20 50 10 25 0
100
200
300
400
500
600
CAPACITY 25
50
75
100
125
C
700 800 U.S. GALLONS PER MINUTE 150
U R V E S
175
CUBIC METERS PER HOUR MAXIMUM IMPELLER DIAMETER HP
FOR FULL MOTOR LOAD
FOR FULL MOTOR LOAD PLUS 15% S.F.
100
15.22"
75
14.50"
15.06"
60
13.56"
13.00"
50
12.56"
12.31"
40
11.81"
12.38"
30
11.06"
11.50"
Feet x .305 = Meters Inches x 25.4 = Millimeters GPM x .227 = Cubic Meters/Hour GPM x 3.785 = Liters/Minute HP x .746 = KW 6/99
Performances shown are for Cool Water, Close-Coupled Electric configuration with Packing. Other mounting styles or liquids may require horsepower and/or performance adjustments.
Cornell Pump Company • Portland, Oregon
CORNELL
41
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Model 4 x 4 x 14T: 1800 RPM-60 Hertz Speed
Impeller Dia.
1760
VARIOUS ENCLOSED
Style
SINGLE VOLUTE
Solids Dia.
NS
Suction
3"
1310
4"
Discharge
No. vanes
4"
2
MOUNTING CONFIG.: CC, VM, F, VF, EM, VC
FEET
METERS
Solids Handling Pump
80 250
60
P
50
E R F O R M A N C E
40
30
TOTAL DYNAMIC HEAD
70
8 FT. (2.4 M.)
275
225
14" DIA
.
45 55
13.5" DIA. 13" DIA.
200 175
12.5" DIA.
10 FT. (3.1 M.) 15 FT. (4.6 M.) 20 FT. (6.1 M.) 65 70 72 74 24 FT. (7.3 M.) NPSH REQ’D. 76 77 78
12" DIA.
75 HP 150 11" DIA. 60 HP 125 10" DIA. 50 HP
100
40 HP 75
30 HP
20 20 HP
50
25 HP
10
C
0
U R V E S
200
400
600
800
1000
1200 1400 1600 U.S. GALLONS PER MINUTE
CAPACITY 50
100
150
200
250
300
350
CUBIC METERS PER HOUR Feet x .305 = Meters Inches x 25.4 = Millimeters GPM x .227 = Cubic Meters/Hour GPM x 3.785 = Liters/Minute HP x .746 = KW 9/27/00
Performances shown are for Cool Water, Close-Coupled Electric configuration with Packing. Other mounting styles or liquids may require horsepower and/or performance adjustments.
CORNELL
42
Cornell Pump Company • Portland, Oregon
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Model 6NHTA: 1800 RPM-60 Hertz Speed
Impeller Dia.
1770
VARIOUS ENCLOSED
Style
Solids Dia.
NS
Suction
3"
2120
6"
SINGLE VOLUTE
Discharge
No. vanes
6"
2
MOUNTING CONFIG.: CC, VM, F, VF, EM, VC
80
FEET
METERS
Solids Handling Pump
70
50
40
30
250
14"
200
DIA
.
225
TOTAL DYNAMIC HEAD
60
275
13"
50
DIA
.
60 15 FT. (4.6 M.) 70 75 80
175 12 "
10 FT. (3.0 M.) 82
DIA
83
.
150 1 1"
15 FT. (4.6 M.) 18 FT. (5.5 M.) NPSH REQUIRED
DIA
83
.
125 10"
P 82
E R F O R M A N C E
80 75
DIA
.
100
75 HP
75
20
60 HP 50 HP 40 HP
50 10
30 HP
25 0 0
500
1000
1500
2000
2500
CAPACITY 100
200
300
400
500
600
C
3000 U.S. GALLONS PER MINUTE
U R V E S
700 CUBIC METERS PER HOUR Feet x .305 = Meters Inches x 25.4 = Millimeters GPM x .227 = Cubic Meters/Hour GPM x 3.785 = Liters/Minute HP x .746 = KW 12/11/00
Performances shown are for Cool Water, Close-Coupled Electric configuration with Packing. Other mounting styles or liquids may require horsepower and/or performance adjustments.
Cornell Pump Company • Portland, Oregon
CORNELL
43
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Model 6NHPP: Various RPM-60 Hertz Solids Dia.
Speed
Impeller Dia.
Style
VARIOUS
13.5"
ENCLOSED
4"x6"
SINGLE VOLUTE
NS
Suction
2600
6"
FEET
METERS
20
P E R F O R M A N C E
15
10
TOTAL DYNAMIC HEAD
25
80 70 60 50 40 30
M M PM M PM RP PM PM P R R R R RP 0 R 00 00 00 0 00 13 80 12 11 10 90
90
1
Food Processing Pump
00
100
6"
No. vanes
MOUNTING CONFIG.: F, VF, EM, VC
14
30
110
Discharge
60 12 FT. (3.7 M.) 70 75 20 FT. (6.1 M.) 75 29 FT. (8.8 M.) NPSH REQUIRED 70 40 HP 60
70
30 HP
0R
PM
25 HP
20 5 10
7.5 HP
20 HP 15 HP 10 HP
0
C
0
U R V E S
500
1000
1500
2000
2500
CAPACITY 100
200
300
400
500
600
4000 3000 3500 U.S. GALLONS PER MINUTE 700
800
CUBIC METERS PER HOUR Feet x .305 = Meters Inches x 25.4 = Millimeters GPM x .227 = Cubic Meters/Hour GPM x 3.785 = Liters/Minute HP x .746 = KW 6/99
Performances shown are for Cool Water, Close-Coupled Electric configuration with Packing. Other mounting styles or liquids may require horsepower and/or performance adjustments.
CORNELL
44
Cornell Pump Company • Portland, Oregon
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Specification Guide CORNELL SOLIDS HANDLING PUMPS Detailed Cornell specifications are available using Cornell’s Centrific© specification program. For more information, contact the factory.
General Requirements Furnish and install ( ___ ) solids handling, end suction, centrifugal pumps. Pumps must have continually rising performance curves to shut-off. Pumps shall be manufactured by Cornell Pump Company 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: _______________ Design capacity: _______________ U.S. GPM
Temperature: _______________ °F Min. efficiency at design point: _______________ %
Design total head: _______________ Ft.
NPSHR: _______________ Ft.
Shut-off head: _______________ Ft.
Suction size: _______________ In.
Max. solids size: _______________ Diameter Max. speed: _______________ RPM
Discharge size: _______________ In. Rotation: _______________ °
Min. motor: _______________ HP
Construction The pump casing shall be of the back pull-out design with heavy sections to provide long life under abrasive 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 volute clean-out plug can be provided as an option. All mating surfaces shall have a register fit to ensure proper alignment.
Impeller The impeller shall be of heavy section cast iron ASTM A48 Class 30 with the (two/three)-port Delta design. Impellers for 4-inch and larger pumps will have back vanes to reduce axial thrust and lower the stuffing 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 stainless steel washer and a stainless steel impeller lock screw.
Stuffing Box The 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 pumpage for lubrication and cooling. A 50 micron filter element shall be used for filtered pumpage. No flush is required for single seal.
Cornell Pump Company • Portland, Oregon
CORNELL
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Wear Rings A single suction wear ring shall be of the peripheral type requiring no adjustment. It shall be press fit into 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 hardness greater than the case ring can be furnished as an option.
Shaft Shaft 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 _____ inches on the pump end bearing and a minimum diameter of _____ inches inside the shaft sleeve. The steps in the shaft shall be properly radiused to reduce stress concentrations. To promote longer seal and bearing lift, 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 Sleeve Shaft shall be protected by a renewable shaft sleeve which extends through the stuffing box and under the 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 Construction AISI 316 or 420 stainless steel, AISI 420 heat treated stainless steel, or bronze.
Bearing Frame and Bearings The bearing frame shall be of one-piece ASTM A48 Class 30 cast iron end covers at both ends. Bearing frames shall be designed (on 4-inch or larger pumps) so that the complete rotating element can be removed 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 Lubrication The 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 contoured clean-out plug. The base shall be of sufficient strength to support the entire weight of the assembled pump and of sufficient height so that no part of the elbow will touch the floor.
Motors The 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 detailed Cornell specifications.
CORNELL
46
Cornell Pump Company • Portland, Oregon
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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 contamination and moisture, seasonal or continuous operation and other factors. The brief recommendations which follow 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 the grease 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. D6A2C5 Mobil Mobillux No. EP2 Shell Alvania EP2 Texaco Multifak No. 2 To lubricate electric motor bearings, use a hand-operated grease gun only. Pump grease into fitting until new grease appears at pressure relief plug. For minimum possibility of over-greasing and for best results, 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 Total Running Time 2,000 hours 8-Hour Day 36 weeks 24-Hour Day 12 weeks
10 to 40 1,500 hours 27 weeks 9 weeks
50 to 150 1,000 hours 18 weeks 6 weeks
Cornell Pump Company • Portland, Oregon
CORNELL
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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 before shipment. Lubrication requirements vary with speed, power, load, ambient temperatures, exposure to contamination and moisture, seasonal or continuous operation and other factors. The brief recommendations which follow 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 the grease 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. D682C5 Mobil Mobilux No. EP2 Shell Alvania EP2 Texaco Multifak No. 2 To lubricate frame bearings, remove the plastic cover from the zerk fittings and be sure the fitting and end of the grease gun are clean. Use a hand operated grease gun only and pump a small amount of grease into each bearing cavity. The surplus grease will go through the bearing and into the center part of the frame. For approximate quantity, refer to the table below. First determine frame size (located on serial number plate). Example: 5HH-65B4 10YB-F18DB 6NHTA-VC18 4RB-EM16
Recommended Regreasing Periods For Frames:
FRAME SIZE
2 - 5 and 11
6-7-8-16 60B4 through 68B4
10-12 18 - 18D
Total Running Time
2,000 hours
1,500 hours
1,000 hours
8 Hour Day Service
36 weeks
27 weeks
18 weeks
24 Hour Day Service
12 weeks
9 weeks
6 weeks
Approximate Amount of Grease per Line Fitting
.5 cubic inch
1.25 cubic inches
2 cubic inches
Approximate Number of Pumps
3 pumps
6 pumps
12 pumps
CORNELL
48
4NNT-VF16
Cornell Pump Company • Portland, Oregon
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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 opening at the top of the housing and fill to the level indicated on the side of the housing. Be careful to keep out dirt and moisture. The oil level must be maintained; check and fill when pump is not operating. The type 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 VG68 Mobil DTE 797 Mobil DTE Oil Heavy Medium Lubriplate HO-0 Lubriplate HO-2 Chevron Turbine Oil GST 32 Chevron Turbine Oil GST 68 Shell 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 oil temperature. 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 through the grease fittings placed in the bearing cover at either end of the frame. Lubricate with a small amount of multiple-purpose grease after every two to six months, depending upon environment. OIL LEVEL INDICATOR
IMPORTANT A. 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.
Cornell Pump Company • Portland, Oregon
CORNELL
49
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Start-up Check List Before the start-up of any pump, a careful check must be made to insure that all is in order. ❏ 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.
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 do so may cause severe damage to equipment and/or personal injury. It may also void the warranty.
CORNELL
50
Cornell Pump Company • Portland, Oregon
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Pump Troubleshooting Guide SYMPTOMS
CAUSES
CORRECTIONS
Failure to pump
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.
Prime pump correctly. Consult Cornell Factory. Consult Cornell Factory. Check and rework suction line. Unplug suction. Consult Cornell Factory.
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.
Locate and correct. Remove obstruction. Consult Cornell Factory. Replace impeller and/or wear ring. Consult Cornell Factory. See start-up instructions.
Driver overloaded
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.
Reduce speed. Consult Cornell Factory. Consult Cornell Factory. Trim impeller. Consult Power Company. Support piping properly. Loosen packing gland and nuts.
Excessive noise
Misalignment. Excessive suction lift Material lodged in impeller. Worn bearings. Impeller screw loose or broken. Cavitation (improper suction design). Wrong direction of rotation.
Align all rotating parts. Consult Cornell Factory. Dislodge obstruction. Replace bearings. Replace. Correct suction piping. See start-up instructions.
Premature bearing failure
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.
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).
Electric motor failure
Overloads.
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.
Rapid wear on coupling cushion
Misalignment. Bent Shaft.
High or low voltage. High electric surge. Bearing failure. Cooling vent plugged (rodent, leaves, dirt, etc.). Moisture or water in motor. Poor electric connection.
Align. Replace Shaft.
Cornell Pump Company • Portland, Oregon
CORNELL
51
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Air Leaks
AIR MAY BE ASPIRATED THROUGH THE PACKING AT HIGH SUCTION LIFTS
PUMP BALANCE DISCHARGE LINE
SMALL LEAKS
AIR
LIQUID
PUMPAGE LEVEL
SUCTION LIFT
FLOW
INJECTION FLOW FROM THE PUMP DISCHARGE STOPS AIR
LARGE BUBBLES
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 the pump to lose performance, efficiency and possibly prime.
CORNELL
52
Cornell Pump Company • Portland, Oregon
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Packing, Wear Rings & Coupling Alignment IMPELLER WEAR SURFACE WEAR RING
RUNNING CLEARANCE
Running clearance for new pumps is about .010 inch on a side. If wear increases this to .032 inch, the wear ring should be replaced and the impeller repaired or replaced. Wear may be caused by abrasives in the pumpage, unsupported piping loads, or other causes. Tighten the gland nuts 1/4 turn every 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.
GLAND NUTS
PACKING PULLER Packing puller used when replacing packing
PACKING PACKING GLAND GLAND LEAKAGE
MOTOR
STRAIGHT EDGE PUMP FRAME
MOTOR
Correct Alignment
MOTOR
STRAIGHT EDGE PUMP FRAME
MOTOR
Incorrect Alignment
CALIPER
NOTES:
PUMP FRAME
Reinstall coupling guard before start-up.
CALIPER
PUMP FRAME
Reinstall coupling guard before start-up.
Cornell Pump Company • Portland, Oregon
CORNELL
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Pump Care
CLOSE COUPLED END SUCTION PUMP Shower Curtain Shield Electric motor
Ever had the brown-grass blues? Have you suffered through costly pump repairs and devastating downtime? If you have answered yes to either of these questions, you need regularly scheduled pump inspection and maintenance.
Impeller
Pump end bearing Packing Wear rings
These are the principal components of a horizontal (frame or close-coupled) mount pump. Pumps need regular maintenance, just like other equipment.
Why is the heart of the irrigation system often neglected until it fails? The answer is simple. Pumps have always been a mystery. Remember the old cliche, “If it’s not broke, don’t fix it”? It must have been created for pumps. Surprisingly, the required pump maintenance ratio per hour of work performed is extremely low.
After 36 years of being a pump doctor, my best advice is:
• Purchase high quality
THE STUFFING BOX Grease cup
•
Sleeve
Packing gland
Impeller
• •
Motor shaft
Lantern ring
Packing
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.
CORNELL
54
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 are gone for good. To get the most from each kilowatt hour, it’s absolutely essential to keep the pump and motor in good repair. Efficiency losses due to wear or neglect will add up to big bucks in operating costs.
Cornell Pump Company • Portland, Oregon
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INSPECTING THE PUMP
connections in the bottom of the install it, so take care if you do discharge head. Connect these to your own maintenance. A typical inspection includes a hose and drain the head. Keep Pumping sand and silt will a look and walk around. Regular the drains open and flowing. naturally shorten the life of the inspections help you develop a You can easily adjust the packing, sleeve, seals and wear sense of what the pump should packing gland and grease cup to rings. Good planning and site sound and feel like. Feel the the manufacturer’s instructions. selection can ensure maximum motors and pumps. Are there any strange noises or vibrations? Special lubrication for the grease service life. cup and packing is available from Can you detect a bearing or If the pump is in the shop for local suppliers. The grease cup motor that is unusually hot? Is lubricates the packing and aids in a sleeve replacement, it’s a good there a new odor or electrical priming horizontal pumps.When time to measure the wear on the smell? wear rings. If the wear is 1/32 of you add a packing ring, be sure Use caution around drive it’s new and clean. Carefully align an inch or .030 per side, it’s time to restore the clearances with couplings and electric controls. the gland without cocking it. new wear rings and impeller Don’t hurt yourself by blundering Tighten evenly to achieve the into something unfamiliar. manufacturer’s specified leakage. repair. The excess wear is costing you wasted energy (and money) This means minimum leakage You can trace many pump through efficiency loss. with a cool stuffing box. breakdowns back to the stuffing LUBRICATION box. A badly leaking packing Replace dried and worn gland or mechanical seal will packing that has lost its lubricaWhat type of lubrication cause problems. Water spraying tion. This requires a special tool should you use and when should into a motor or bearing frame called a packing hook. Packing you use it? These questions are will infiltrate the pump end hooks are also available from asked repeatedly. If your motor, bearing. It will wash all lubrication local suppliers. has Zerk grease fittings, it from the bearing, causing rust After removing all the packing, requires greasing. Some of the and imminent failure. smaller sizes, usually 3 to 5 HP inspect the shaft sleeve. If the If water collects under a sleeve is grooved or worn, packing pumps, won’t have Zerk fittings. These motors have sealed bearings horizontally mounted motor, replacement will have a short the ventilation fan (which blows life. You need to replace the sleeve. and don’t require greasing. onto the motor winding) will This requires disassembling the When you add grease, be pull the water into the motor. pump. If you have a horizontal sure the grease and the fittings This may cause a burned-out unit, take it to the shop. Vertical are absolutely clean. The code motor. Water squirting up into turbines usually require motor number for the proper grease a vertical, hollow-shaft motor removal and head shaft renewal. is EP-2. Other greases, such as of a vertical turbine pump will multi-purpose types, may work, If your pump is equipped cause the same problems. These but bearing manufacturers with a mechanical seal, never motors are not water-cooled. allow it to run dry, even for a few recommend only EP-2. The Electric motor service life seconds. Water lubricates the seal exception is if the motor or pump manufacturer specifically recomdepends on a dry, clean atmosphere. faces. A dry run merely bums it mends a different lubricant. Elevate a horizontally mounted out. At the first sign of a leak, pump at least 6 inches off the replace the seal. This will require To lubricate electric motor floor, and install a line to drain disassembly, which a pump bearings, remove the relief grease the leakage away from the motor. technician normally does. You plug. Using a hand grease gun, can damage a new seal if you pump the new grease into the Vertical turbines have drain mishandle it or improperly
Cornell Pump Company • Portland, Oregon
CORNELL
55
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fitting until it shows at the drain. Do this when the unit is not running so you avoid getting grease into the motor. I like to leave the drain plug out for a few days to let the excess grease work its way through the drain, not into the motor.
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in the operator’s manual for greasing frequency. A drain plug is usually a pipe plug near the 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 The bearings will run unusua long life. ally hot for about 20 minutes after greasing because the bearing Many motors have rodent is purging the grease from the screens installed on the vents. balls and race. As the bearing These are essential to keep critters out, but they require periodic BEARING LUBRICATION cleaning. Keep them free of lint, chaff, weeds, dirt and other debris to ensure a free, cool, air flow.
Zerk Fitting
Drain
Grease In
Grease Out
This is the grease flow pattern for bearing lubrication of an electric motor.
warms up, it turns the grease to oil. It’s this mist of oil that actually lubricates the bearing. Therefore, it’s absolutely essential to use the Code EP-2 for proper melting temperature.
I am a believer in well ventilated shelters that protect pumping equipment and switch gear from sun and rain. The sun’s direct rays can add 10 to 20 degrees of ambient temperature to the motor temperature. For every 18° Fahrenheit temperature rise above the motor nameplate rating, the expected motor life is reduced by one-half. Thermostat controlled exhaust fans help keep the inside temperature and air flow cool in pump houses.
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put a tremendous weight load on the pump casing. Pipelines can break the casings if the weight load is severe enough. The pipelines must be supported so the pump can be removed with no stress or strain on it. I like to see one flexible-type pipeline coupling in either the inlet line or discharge line. A noise developing in a pump that has otherwise been running quietly usually indicates a bearing is beginning to fail. Replace the bearing immediately. Neglect could irreparably damage the motor or the frame.
PIPE SUPPORTS
Concrete with metal strap.
VIBRATIONS
What does an extreme vibration signal? It could be the result of a misaligned drive coupling or the start of bearing failure. Some pump units can actually twist on their bases if the Pumps mounted on bearing base construction is too light or if frames (those that have a separate they are not secured and grouted motor) are normally greased properly to the foundation. through the bearing cover. Excess grease accumulates in the large Pipeline misalignment can cavity of the frame. It takes also lead to vibration. Unsupyears to fill the frame. Follow ported pipelines full of water the manufacturer’s instructions CORNELL
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Cornell Pump Company • Portland, Oregon
J bolts or anchor bolts.
Use pads between piping and support.
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A bearing that repeatedly fails indicates a possible misalignment or strain. Occasionally, I have found the bearing is either the wrong type or not heavy enough for the application. If you’re in doubt, request a B-10 bearing life calculation from the pump manufacturer.
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in controls and pump starters. He should check the contacts in the starter and replace any that show signs of uneven or heavy pitting. If neglected, these are going to heat and cause high current to trip out the overload protection device.
Have the electrician check and tighten each and every screw in the panel. After several years, normal heat and temperature changes tend to loosen the terminal screws. A loose connection will cause heat, burn out wiring, damage the contactor and/or cause short motor cycling and overheating. Remember, maintaining a low temperature rise in the electric motor will ensure a long service life.
If you want to burn out the motor, install overload heaters with too high a rating or adjust THE ELECTRIC SYSTEM the overload trip rating up too Electric switch gear needs high. I have actually seen a periodic inspection and motor starter jammed shut by a maintenance as well as the stick wedged against the door. Illustration: Author. pump and motor. This requires The price tag for this “good idea” an electrician who is experienced – a 150-HP motor rewind.
PUMP HOUSE
Adequate ventilation includes screens and shades
Use large, concrete, thrust blocks even on subsurface piping
Place electrical control near door
Security lock
Equipment access
Proper site drainage
Subsurface piping is prefered for protection against freezing
Inflow Outflow
Cornell Pump Company • Portland, Oregon
CORNELL
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Notes
CORNELL
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Cornell Pump Company • Portland, Oregon
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Notes
Cornell Pump Company • Portland, Oregon
CORNELL
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Notes
CORNELL
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Cornell Pump Company • Portland, Oregon
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CO NPSHA = P + LH - (VP + hf)
NPSHA = P - (VP + LS + hf)
CORNELL PUMP COMPANY P.O. Box 6334 Portland, Oregon 97228-6334 Phone: 503/653-0330 Fax: 503/653-0338
CORNELL Manufacturers of Quality Pumps Since 1946
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