Pump classification

Hydrodynamic (or) non-positive displacement

pumps

Hydrostatic (or) positive displacement pumps

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

Hydrostatic pumpsHydrostatic 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 displacementThese 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.

CLASSIFICATION OF PDP

GEAR PUMP

SVANE PUMP

S

PISTON PUMPS

EXTERNAL GEAR PUMP

Common external gear pump applications include, but are not limited to:Various fuel oils and lube oilsChemical additive and polymer meteringChemical 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

INTERNAL GEAR PUMP

Common internal gear pump applications include, but are not limited to:All varieties of fuel oil and lube oilResins and PolymersAlcohols and solventsAsphalt, Bitumen, and TarPolyurethane foam (Isocyanate and polyol)Food products such as corn syrup, chocolate, and peanut butterPaint, inks, and pigmentsSoaps and surfactantsGlycol 

APPLICATION

LOBE PUMP

Common rotary lobe pump applications include, but are not limited to:PolymersPaper coatingsSoaps and surfactantsPaints and dyesRubber and adhesivesPharmaceuticalsFood applications 

APPLICATION

GEROTOR PUMP

SCREW PUMP

PD pumps are found in a wide range of applicationchemical-processingliquid deliverymarinebiotechnology pharmaceuticalas 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

VANE PUMPS

Aerosol and PropellantsAviation Service - Fuel Transfer,

DeicingAuto Industry - Fuels, Lubes,Refrigeration CoolantsBulk Transfer of LPG and NH3LPG Cylinder FillingAlcoholsRefrigeration - Freons, AmmoniaSolventsAqueous solutions

APPLICATION

AXIAL PISTON PUMP

RADIAL PISTON PUMP

Centrifugal pump

Submersible pump

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

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.

PUMP EFFICIENCIESVolumetric Efficiency:η = Actual flow rate = Qa Theoretical flow rate QtGear pumps = 80-90 %Vane pumps = 82-92 %Piston pumps = 90-98 % Mechanical Efficiency:η = Output power = Po Input power PiMechanical 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

REFFRENCE1. WWW.PUMPSSCHOOL.COM 2. APPLIED HYDRAULICS AND

PNEUMATICS By T.Sunder Selwyn, R.Jayendiran

3. www.authorstreem.com.