Types of groundwater pumps

1. Table of Contents
Types of Groundwater Pumps .............................................................................................................1
Introduction...................................................................................................................................1
1. Hand and Treadle Pumps.............................................................................................................1
2. Low Pressure Suction Pumps........................................................................................................2
3. High Pressure Suction Pumps.......................................................................................................2
3.1 Centrifugal Pumps..................................................................................................................2
3.2 Positive Displacement Pumps:................................................................................................3
Other types of pumps .....................................................................................................................4
Submersible Pumps.....................................................................................................................4
Jet pumps.......................................................................................................................................4
Types of Groundwater Pumps
Introduction
A pump is a device that moves fluids (liquids or gases), or sometimes slurries, by mechanical
action. Pumps can be classified into three major groups according to the method they use to
move the fluid: direct lift, displacement, and gravity pumps.
Pumps operate by some mechanism (typically reciprocating or rotary), and consume energy to
perform mechanical work by moving the fluid. Pumps operate via many energy sources,
including manual operation, electricity, engines, or wind power, come in many sizes, from
microscopic for use in medical applications to large industrial pumps
There are different types of groundwater pumps used to move water, depending mainly on the
depth at which it is found. Ground water may be just below the surface or in the deep of the
earth, depending on the location. The original way of moving groundwater was from an open
well using a bucket and rope. This method is still applied in many places, though it is limited in
terms of the volume of water that can be moved as well as the depth from which it can be
fetched. Modern pumps will move water from great depths via pipes and at high speeds. There
are several types of these modern pumps:
1. Hand and Treadle Pumps
Hand pumps are manually operated pumps; they use human power and mechanical advantage to
move fluids or air from one place to another. They are widely used in every country in the world
for a variety of industrial, marine, irrigation and leisure activities. It is more efficient when
compared to using a bucket and rope but cannot be used in a commercial setting due to the

2. limitation of being manually powered. These pumps are easy to assemble and maintain. They are
cost effective and work well where the water is not very deep.
The treadle pumps will, however, give more output, as it is powered using a leg pump as
opposed to a hand pump. These pumps are mainly used to irrigate small pieces of land. There are
many different types of hand pump available, mainly operating on a piston, diaphragm or rotary
vane principle with a check valve on the entry and exit ports to the chamber operating in
opposing directions. Most hand pumps have plungers or reciprocating pistons, and are positive
displacement
2. Low Pressure Suction Pumps
These types of pumps use a sucking force or pressure which pulls up the water from the source.
These pumps are used above the ground and need to be near the water source, as they are not
very powerful. Their lack of power means that they can only operate at depths of up to 7
meters. The types of suction pumps include a piston, the diaphragm and semi-rotary pumps.
These pumps are ideal for moving water from a river, stream, lake or swamp to a nearby
reservoir or sprinkling on nearby plants.
3. High Pressure Suction Pumps
These are high performance pumps that can get water from very deep. They will usually have a
motor action involved in their operation and are very powerful. These pumps are more expensive
to purchase and run, but they will, however, give higher output. There are many variations to
these pumps, but they come in two main categories: centrifugal pumps and positive displacement
pumps.
3.1 Centrifugal Pumps: Centrifugal pumps use a rotating motion to propel the water
through the pipes. These pumps will have increased output when they have increased
blade surface on their rotors.
Very simple design
Two main parts are the impeller and the diffuser
Impellers which are the rotating part of a centrifugal pump, compressor, or other machine
designed to move a fluid by rotation made up of Bronze, poly carbonate, cast iron etc.
Diffuser made up of stainless steel. A diffuser is a set of stationary vanes that surround
the impeller. The purpose of the diffuser is to increase the efficiency centrifugal pump by
allowing a more gradual expansion and less turbulent area for the liquid to reduce in
velocity.
Size of the pump depends on head and capacity. Advantage of this type of pump is it is
Very efficient, Produce smooth and even flow, Reliable with good service life.
Disadvantages are Loss of priming easily and Efficiency depends upon operating design
head & speed.

3. 3.2 PositiveDisplacementPumps: Positive displacement pumps have an expanding
cavity on their suction side while the cavity decreases on the discharge side. They
provide a constant volume even when there is variance in the discharge pressure. They
are also referred to as constant flow pumps.
-Reciprocating A reciprocating pump is a class of positive-displacement pumps which
includes the piston pump, plunger pump and diaphragm pump. When well maintained,
reciprocating pumps will last for years or even decades; however, left untouched, they
can undergo rigorous wear and tear. It is often used where a relatively small quantity of
liquid is to be handled and where delivery pressure is quite large. In reciprocating pumps,
the chamber in which the liquid is trapped, is a stationary cylinder that contains the piston
or plunger.
-Rotary These pumps move fluid using a rotating mechanism that creates a vacuum that
captures and draws in the liquid
Advantages: Rotary pumps are very efficient because they naturally remove air from the
lines, eliminating the need to bleed the air from the lines manually.
Drawbacks: The nature of the pump requires very close clearances between the rotating
pump and the outer edge, making it rotate at a slow, steady speed. If rotary pumps are
operated at high speeds, the fluids cause erosion, which eventually causes enlarged
clearances that liquid can pass through, which reduces efficiency.
Rotary positive displacement pumps fall into three main types:
Gear pumps - a simple type of rotary pump where the liquid is pushed between two
gears
Screw pumps - the shape of the internals of this pump is usually two screws turning
against each other to pump the liquid
Rotary vane pumps - similar to scroll compressors, these have a cylindrical rotor
encased in a similarly shaped housing. As the rotor orbits, the vanes trap fluid between
the rotor and the casing, drawing the fluid through the pump.
It is important to identify the correct pump you need depending on the purpose while also
keeping in mind the power source, availability of parts and servicing technicians. All
these factors should guide you in acquiring the type of pump suitable for you.

4. Other types of pumps are:-
SubmersiblePumps
Centrifugal pump closely coupled with motor
Does not require long drive shaft
Motor operates at a cooler temperature.
Noiseless operation.
High efficiency
Smooth and even flow
case of repair full pump to be removed
Jet pumps
Combination of a surface centrifugal pump, nozzle and venturi arrangement.
Used in small dia bore wells.
Simple design
Low purchase and maintenance cost.
Easy accessibility to all moving parts.
Low efficiency.