3. 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
4. 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.
7. 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. Common internal gear pump applications include, but
are not limited to:
All varieties of fuel oil and lube oil
Resins and Polymers
Alcohols and solvents
Asphalt, Bitumen, and Tar
Polyurethane foam (Isocyanate and polyol)
Food products such as corn syrup, chocolate, and
peanut butter
Paint, inks, and pigments
Soaps and surfactants
Glycol
APPLICATION
11. Common rotary lobe pump applications
include, but are not limited to:
Polymers
Paper coatings
Soaps and surfactants
Paints and dyes
Rubber and adhesives
Pharmaceuticals
Food applications
APPLICATION
14. 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
23. NON-POSITIVE
DISPLACEMENT PUMPS
POSITIVE DISPLACEMENT
PUMPS
provide a smooth, continuous flow pulse with each stroke or each time
a pumping chamber opens to an
outlet port.
Pressure can reduce a non positive
pump's delivery. High outlet
pressure can stop any output; the
liquid simply recirculates inside the
pump
In a positive-displacement pump,
pressure affects the output only to
the extent that it increases internal
leakage
It is not self priming It is a self-priming
CHArACTeriSTiCS OF
pumpS
24. 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.
25. 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