It covers the classification of pumps,design criteria and energy efficient methods

1. PUMP

2. PumP classification
Hydrodynamic (or) non-positive
displacement pumps
Hydrostatic (or) positive
displacement pumps

4. Carries fluid from one location to another, relatively
at low pressure (17-21 bar).
Generally used for low pressure, high-volume, flow
applications.
These pumps are not self-priming, as there is a great
deal of clearance between the rotating and
stationary elements.
Cannot create enough vacuum at its inlet, hence
discharge rate is low.
Examples…..
a) Centrifugal pumps
b) Axial flow propeller pump.
These pumps are called as non-positive displacement
pumps.
HYDRoDYnamic PumPs

5. HYDRostatic PumPs
Hydrostatic pumps uses fluid pressure to transmit
power.
These pumps have very close-fitting mating
components and hence a very small amount of
leakage could occur.
These pumps may be either…..
a) Fixed displacement
b) Variable displacement
These pumps requires protection against over
pressure if the resistance to flow becomes very
large or infinite, so pressure relief valve is
provided.
It is also called as positive displacement pumps.

6. classification of PDP
GEAR
PUMPS
VANE
PUMPS
PISTON
PUMPS

7. EXtERnal GEaR PumP

8. Common external gear pump applications
include, but are not limited to:
Various fuel oils and lube oils
Chemical additive and polymer metering
Chemical mixing and blending (double pump)
Industrial and mobile hydraulic applications
(log splitters, lifts, etc.)
Acids and caustic (stainless steel or
composite construction)
Low volume transfer or application
aPPlication

9. PD pumps are found in a wide range of application
chemical-processing
liquid delivery
marine
biotechnology
 pharmaceutical
as well as food, dairy, and beverage processing.
Their versatility and popularity is due in part to
their relatively compact design, high-viscosity
performance, continuous flow regardless of
differential pressure, and ability to handle high
differential pressure.
APPLICATIONS OF PDP

10. VANE PUMPS

11. Aerosol and Propellants
Aviation Service - Fuel Transfer, Deicing
Auto Industry - Fuels, Lubes,
Refrigeration Coolants
Bulk Transfer of LPG and NH3
LPG Cylinder Filling
Alcohols
Refrigeration - Freons, Ammonia
Solvents
Aqueous solutions
APPLICATION

12. CENTrIFUgAL PUMP

13. SUbMErSIbLE PUMP

14. DYNAMIC PUMP POSITIVE DISPLACEMENT
PUMPS
provide a smooth, continuous flow Pulsating flow
Head varies with flow rate Constant flow rate for virtually any
pressure
It is not self priming
Viscocity has strong effect
It is a self-priming
Virtually no effect
CHArACTErISTICS OF
PUMPS

15. CENTRIFUGAL PUMPS, contd.
 Q. FOR AN 1800 RPM PUMP FIND THE DIAMETER
OF IMPELLER TO GENERATE A HEAD OF 200 FT.
 Find first initial velocity V = (2gh)1/2 = 113 ft/sec
 Convert RPM to linear distance per rotation
 1800 RPM = 30 RPS →V/RPS = 113/30 = 3.77 ft/rotation
 3.77 = circumference of impeller → diameter = 1.2 ft = 14.4
inches
 CONCLUSION
 FLOW THROUGH A CENTRIFUGAL PUMP FOLLOWS
THE
 SAME RULES OF FREELY FALLING BODIES
 DO WE GET
 THE SAME DIAMETER OR HEAD OR FLOW RATE
 AS PREDICTED BY THESE IDEAL RULES

16. Net Positive Suction Head
 NPSH is the minimum pressure required at the inlet part
of the pump to avoid cavitation. NPSHA is a function of
your system and must be calculated. NPSHR is a function
of the pump and must be provided by the pump
manufacturer.
 NPSHA > NPSHR
 If system changes aren’t feasible or aren’t adequate to
increase the NPSHA, consult with the pump manufacturer
about reducing the NPSHR. In the case of a positive
displacement pump, this will likely mean going with a
larger model and slowing it down. For example, a gear
pump generating 100 GPM at 780 RPM has an NPSHR of
9.1 feet of water. By switching to a larger pump running at
350 RPM to generate the same 100 GPM, the NPSHR
drops to 3.8 feet of water. Slowing the pump allows more
time for the tooth cavities to fill, allowing the pump to
operate without cavitating even at low suction pressures

17.  The type of applications for which centrifugal pumps are
required are;
1. High head low flow rate
2. Moderate head and moderate flow rate
3. Low head and high flow rate
 Q. Would a general design of the centrifugal pump will do
all the three jobs?
Ans. No
 Q. What should be the design features to accomplish the
three specified jobs?
1. Answer to this question lies in the basic concept of
centrifugal
pump working principle.
2. Vanes are used to impart momentum to the fluid by
applying thecentrifugal force to the fluid.

18. PHYSICS FOR OUR RESCUE
1. Answer to this question lies in the basic concept of
centrifugal pump working principle.
2. Vanes are used to impart momentum to the fluid by
applying the centrifugal force to the fluid.
3.More the diameter of vane more the centrifugal force.
4.More the diameter more will be the radial component
of velocity and less will be the axial component.
5.More the radial velocity more will be the head
developed.
6.Hence to get more head you need longer vanes and
viceversa.
7.More will be the clearance between impeller and
casing, more will the flow rate and also axial
component.
8.The simple physics principles lead us to the variation in
impeller design to accomplish the three jobs
mentioned.

19. PERFORMANCE OF PUMP
 Pumps are usually rated according to their volumetric output
and pressure.
 Volumetric output (delivery rate or capacity) is the amount of
liquid that a pump can deliver at its outlet port per unit of time
at a given drive speed, usually expressed in GPM or cubic
inches per minute.
 Pumps are sometimes rated according to displacement, that is
the amount of liquid that they can deliver per cycle or cubic
inches per revolution.
 As pressure increases, volumetric output decreases.
 This drop in output is caused by an increase in internal leakage
(slippage) from a pump's outlet side to its inlet side
 Slippage is a measure of a pump's efficiency and usually is
expressed in percent.

20. PUMP EFFICIENCIES
Volumetric Efficiency:
η = Actual flow rate = Qa
Theoretical flow rate Qt
Gear pumps = 80-90 %
Vane pumps = 82-92 %
Piston pumps = 90-98 %
Mechanical Efficiency:
η = Output power = Po
Input power Pi
Mechanical efficiency varies from 90 to 95 %
Overall Efficiency:
η = Actual power delivered by the pump = Hydraulic power
Actual power delivered to the pump Brake power

21. Pump performance curve

22. TITLE BOX
 The title box provides information about the pump model, size, speed, and other
identifying criteria specific to the pump. If checking the performance of an
existing pump, confirm that you are matching the pump to the associated curve.
FLOW
 To start your selection, identify the amount of flow you require from the pump.
For this example, we have chosen 300 gpm. Flow is indicated across the bottom
horizontal axis of the curve.
HEAD
 You will also need to know the total head the pump is required to overcome at the
specified flow. For this example, we will use 100 ft. Head is indicated in
increments along the vertical axis. Follow 100ft across the curve intersects your
flow line which indicates your performance point.
IMPELLER TRIM
 To accommodate different performance points, centrifugal pumps have the
capability of trimming impellers. By reducing impeller size, the pump can be
limited to your specific performance requirement. The impeller diameters are
listed on the left side of the curve and the performance for each trim is shown
across as a bold line. Our selection is between 10” and 11” so a trim of 10.5” is
appropriate.
Centrifugal pumps can also be limited by variable speed, which is the ideal means
of control when several performance points are required by a single pump and not
achieved by a single trim without system modification. Variable speed curves will
be covered in a later post.

23. HORSEPOWER
 Now that you have your performance point, we can determine the
amount of horsepower required. Horsepower is indicated across the
curve as a dotted line in this case at a downward angle. Our
performance point is between the 10hp and 15 hp lines, we estimate this
selection to require 12 hp.
NPSHR
 Net positive suction head required is important for proper pump
operation. This is the minimum amount of pressure on the suction side
of the pump to overcome pump entrance losses. If sufficient NPSH is not
met the pump will cavitate which will affect performance and pump life
.
EFFICIENCY
 When selecting the best pump for an application, efficiency many times
is an important factor. The higher the efficiency, the less energy
required to operate for a specific performance point.
MINIMUM FLOW
 A centrifugal pump requires a minimum amount flow to be moving
through the pump to dissipate heat created. On the left side of the
curve, minimum flow is indicated by a vertical bold line; operation to the
left of this line is not recommended and can significantly decrease the
life of the pump.

24. HORIZONTAL SPLIT CASE PUMP
The HSC pump is a horizontal, single stage, double suction, double volute axially split case
centrifugal pump. The suction and discharge nozzles are integrally cast in the lower half of the
casing and on the same horizontal centerline. The nozzle configuration is side/side .
CHARACTERISTICS
 High Efficiency design.
 Single stage, horizontal split case centrifugal pump.
 Horizontally split casing, double volute minimizes thrust loads and allow operation over and wide range of
capacities.
 Flanged connections.
 Enclosed impellers, double suction provides hydraulic balance eliminating axial thrust.
 Clockwise or counter clockwise rotation.
 Double ended shaft available.
 Foot Mounted.
DESIGN FEATURES
 Oil or grease lubricated bearings.
 Stuffing box configured for packing or mechanical seals.
 Horizontal or vertical mounting configurations.
 Renewable wear rings.
STANDARD CONSTRUCTION MATERIALS
 Cast Iron.
 Cast Iron, Stainless Steel Fitted.
 All Bronze.
 All WCB grade Carbon Steel.
 All Stainless Steel

25. OPERATION LIMITS
 Capacity up to 31,800 m³/h
(140,000 U.S. gpm).
 Head up to 168 m (550 ft).
 Discharge flange size 5'' to 36''.
 Maximum Pressure 28 bar (400 psi).
 Temperature 10 to 150 ºC
(50 to 300 ºF).
APPLICATIONS
 Fire Service.
 Cooling Towers.
 Municipal.
 Oil Process.
 Petrochemical.
 Sugar Industry.
 Paper Industry.
 Pipeline.
 Power Generation.
 Dewatering.
 Mining.
 Water.

26. End suction pump
An end suction water pump would probably have the lowest initial cost for
most applications, with reasonable efficiency. However, these pumps do
not follow any standards, especially with regard to bearing life, shaft seal
housings and dimensional interchangeability. They are also typically
constructed with the lowest cost materials, such as cast iron casings with
bronze or brass impellers. The impellers are typically of closed
construction, without replaceable casing or impeller wearing rings.
Further, there is typically more deviation from published performance,
such as efficiency, for this pump type.

27. Vertical inline pump

28. MECHANICAL SEAL
Pusher type mechanical seal
The pusher type of mechanical seals move axially along the
rotating shaft or the sleeve to maintain the contact with the faces
of the seal. This feature of these seals helps compensate for the
wearing that may occur at the seal face, and wobbling due to
misalignment. The pusher types of mechanical seals are used
commonly, are less expensive and are easily available in the
market in wide range of sizes and designs .
Unbalanced type mechanical seal
The unbalanced types of mechanical seals are used under drastic
conditions where there are vibrations, misalignment of the shaft,
and the problem of the cavitation of the fluid .
Non pusher type mechanical seal
The non-pusher or bellow type of mechanical seals don’t have to
be moved axially to maintain their contact with the faces. These
seals can work under low temperature and high pressure
applications.

29. Balanced type mechanical seal
The balanced mechanical seals have the ability to sustain higher
pressures across the faces and they generate lesser heat thus they
are suitable for handling liquids that have low lubricating
capacity and hydrocarbons that have high vapor pressure.
Catridge seal
The major advantage of the cartridge seals is that they don’t
require complicated seal setting measurement during the
installation as required by the conventional seal. This helps
reducing errors associated with seal setting and eventually also
reduces the maintenance required.