S chlu mb er g er P riv ate
Centrifugal Pump
S chlu mb er g er P riv ate
Centrifugal Pumps
The term “centrifugal pump” has been used
to describe a wide variety of pumping
applications and designs throughout the
years.
S chlu mb er g er P riv ate
Centrifugal Pump
The REDA centrifugal pump
is a multistage pump,
containing a selected
number (application
dependent) of impellers
equipped with vanes, inside
a closely fitted diffuser,
located in series an axial
shaft, driven by the electrical
motor.
S chlu mb er g er P riv ate
Centrifugal Pump
A centrifugal pump creates pressure by
the rotation of a series of vanes in an
impeller.
The impeller’s job is to transfer energy by
rotation to the liquid passing through it, thus
raising the kinetic energy.
S chlu mb er g er P riv ate
Centrifugal Pump
The diffuser section then converts this energy
to potential energy, raising the discharge
S chlu mb er g er P riv ate
Centrifugal Pump
From there, the rotation of
the high-speed impeller
throws the liquid into the
diffuser.
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Centrifugal Pumps
Each "stage" consists of an
impeller and a diffuser. The
impeller takes the fluid and
imparts kinetic energy to it. The
diffuser converts this kinetic
energy into potential energy
(head or pressure).
Upthrust Washer
Impeller
Down Thrust Washer
Diffuser
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•
Curves for centrifugal
pumps are normally
shown as flow versus
head in feet, meters,
or some other
consistent unit.
Head: The height
to which the pump
will "lift" the fluid
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0
10000
20000
30000
20000
10000
0
T
ota
l
Dynamic Hea
d
-Feet
15000
5000
Flow Rate - BPD (60 Hz)
Maximum Head-Capacity
5.5" Casing
7" Casing
4.5" Casing
REDA
Rev. B
SN2600 60 HZ / 3500 RPM
Pump Performance Curve 538 Series - 1 Stage(s) - Sp. Gr. 1.00Optimum Operating Range Nominal Housing Diameter Shaft Diameter
Shaft Cross Sectional Area Minimum Casing Size
1600 - 3200 5.38 0.875 0.601 7.000 bpd inches inches in2 inches
Shaft Brake Horsepower Limit: Housing Burst Pressure Limit:
Standard High Strength Standard Buttress Welded 256 410 N/A 6000 6000 Hp Hp psi psi psi
REDA
Rev. B
SN2600 60 HZ / 3500 RPM
Pump Performance Curve 538 Series - 1 Stage(s) - Sp. Gr. 1.00Optimum Operating Range Nominal Housing Diameter Shaft Diameter
Shaft Cross Sectional Area Minimum Casing Size
1600 - 3200 5.38 0.875 0.601 7.000 bpd inches inches in2 inches
Shaft Brake Horsepower Limit: Housing Burst Pressure Limit:
Standard High Strength Standard Buttress Welded 256 410 N/A 6000 6000 Hp Hp psi psi psi
Eff
Hp
Feet
60%
B.E.P.
Q = 2581
H = 46.75
P = 1.31
E = 68.09
60
3.00
Schlu40%
50%
40
50
2.00
2.50
mber ge r Priv ate30%
30
1.50
10%
20%
10
20
0.50
1.00
0
500
1,000
1,500
2,000
2,500
3,000
3,500
4,000
Capacity - Barrels per Day
•
From this curve we can determine the head produced, brake
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Impeller Thrust
Cross-Section of a Typical Impeller
An Impeller has three forces acting on it.
The sum of these three forces is the total
thrust.
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Pressure
: F = Press x Area
Low Pressure
High Pressure
Impeller Thrust
Gravity: F=mA
Momentum:
F = d(mass) x velocity + d(velocity) x mass
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P
ressure: By using a "balance ring" between the impeller and
diffuser and drilling "balance holes" in the upper
impeller skirt, we can recirculate lower pressure
fluid over the majority of the upper surface.
Balance
Ring
Balance
Hole
Low Pressure Fluid
Low Pressure
High Pressure
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Efficiency
Flow Rate
% Horse Power
0%
0%
100%
100%
Mechanical
Natural Leakage
Recirculation
from Impeller
Shape
Hydraulic
Loss
Pump Output
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Pump Descriptions and Names
The series designations are defined as:
Type
Series
Outside
Diameter
Minimum
Casing Size
A
338
3.38”
4 ½”
D
400
4.00”
5 ½”
G
540
5.13”
6 5/8”
S
538
5.38”
7”
H
562
5.63”
7”
J
675
6.75”
8 5/8”
L
738
7.25”
9 5/8”
M
862
8.63”
10 ¾”
N
950
9.5”
11 ¾”
950
10.00”
11 ¾”
P
1125
11.25”
13 3/8”
DN 1300
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Pump Descriptions and Names:
• N = NiResist
• R = 5530
• V = Type 4
• Many other letters will be used to discribe
the pump…
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Pump Nomenclature:
Frequently Used Terms
Abbreviation Definition
ARZ Abrasion Resistant: Zirconia bushings and sleeves ARZ-S Abrasion Resistant: Silicon Carbide sleeves
ARZ-SS Abrasion Resistant: Silicon Carbide bushing and sleeves ARZ-T Abrasion Resistant: Tungsten-Carbide sleeves
ARZ-TT Abrasion Resistant: Tungsten-Carbide bushings and sleeves ARZ-ZS Abrasion Resistant: Zirconia bushing bushings and Silicon sleeves ARZ-ZT Abrasion Resistant: Zirconia bushing bushings and Tungsten sleeves C Compression
CT Center Tandem
C-CT Compression-Center Tandem C-LT Compression-Lower Tandem CR Compression Ring
CR-CT Compression Ring-Center Tandem CR-LT Compression Ring-Lower Tandem ES Enhanced Stability FL Floater FL-CT Floater-Center Tandem FL-LT Floater-Lower Tandem FL-S Floater-Single section HB Hydraulic Balance HSG Housing S Single SS Stainless Steel
SS H and B Stainless Steel Head and Base CS Carbon Steel
M-Trim Monel Trim Rloy Redaloy
SLB Self Lubricating bearings (Graphalloy) HSS High Strength Shaft
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Pump naming conventions
DN1400 indicates:
D
= 400 series, therefore, 4.0” in diameter
N
= the material of the stage, in this case
ni-resist.
1400 = the best efficiency flow rate
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Pump Construction
There are two types of pump stage
construction for ESP oil field applications:
Floater - Type
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2 Types of Stage Construction
Pump
Down
Thrust
Carried
here
Impeller
Thrust
Compression
Floater
Protector
Thrust
Bearing
Motor
Thrust
Bearing
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"Compression" Pumps
In a compression pump, all the impellers are rigidly fixed to
the shaft so that if an impeller wants to move up or down, it
will take the shaft with it.
The impeller is normally sitting down on its lower diffuser
during assembly due to gravity. Because of this, the pump
shaft is "raised" with shims in the coupling so that the impeller
is not allowed to touch the diffuser after final assembly. This
allows all thrust developed in the pump shaft to be transferred
to the protector shaft directly.
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There is a small amount of free play in the
coupling such that the pump shaft can fall
down to where the impellers ride directly on
the lower diffusers or on the downthrust
washers if available.
Impeller is in full down
position
Pump
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Add shims so the impeller is
lifted slightly off diffuser.
Shims placed in
coupling to raise
the shaft
Pump
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Why use Compression Pumps?
•
Some stages generate too much thrust to be handled by a thrust
washer in the stage.
•
Some fluids (e.g. liquid propane) do not have enough lubricity to
properly lubricate a thrust washer.
•
If abrasives or corrosives are present, it may be beneficial to handle
the thrust in an area lubricated by motor oil rather than well fluid.
•
Occasionally in very gassy wells, the flow volume changes so
drastically within the pump that parts of a floater pump could be in
very severe thrust while others are not so a compression pump could
be one alternative.
•
Since all the thrust is handled in the protector, as long as the
protector has a great enough capacity, the pump operating range can
be extended over a much wider area without any increased wear or
reduced life.
S chlu mb er g er P riv ate
Centrifugal Pumps
A radial flow
(pancake) impeller
has vane angels at
close to 90 degree,
and therefore, are
usually found in
pump ranges for
lower flow rates.
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