Page 1The Enduring Benefits of Eccentric Disc Pumps
As the 20th century dawned, the second Industrial
Revolution, also known as the Technological Revolution,
was moving ahead full steam. The Bessemer steel process
had become the first inexpensive way to mass-produce
steel from pig iron, which resulted in a building boom.
Automobiles were on the way to becoming a more common
sight on the streets of major cities than horse-drawn
carriages. The gas lamp was making way for the more
efficient and safer incandescent light bulb.
At that time, Frenchman Andre Petit had just graduated
from the renowned Ecole Centrale Engineers’ College in
Paris with a degree in engineering. Taking a job in the gold-
mining industry, he found himself traveling throughout
central Asia, even as far as China. He also found himself
wondering how he could improve the operational
performance and reliability of the industrial pumps that
were used to transfer water and other produced liquids out
of gold mines.
By 1906, he had perfected the answer, which he called the
“eccentric movement principle” of pump operation, which
he proved would succeed where other pump technologies
fail. Petit was so confident in the potential of this new
pump technology that he formed his own company, which
he named Mouvex® and headquartered in Paris, France.
More than a century later, Mouvex, which relocated its
operations in 1974 to a 100,000-square-foot manufacturing
complex in the city of Auxerre, southeast of Paris, remains
a global leader in outfitting a wide array of industries
with eccentric disc pumps for use in transfer applications
that require constant flow rates, leak-free operation and
accurate dosing.
Surveying the FieldAs Petit began the search for a better pump design,
internal gear and lobe-style were the preeminent pump
technologies. These workhorse pumps proved perfectly
capable of handling basic liquid-transfer operations, but
both styles featured shortcomings that would ultimately
compromise an operation’s efficiency, reliability, and cost-
effectiveness over time.
more than a century after its invention, andre petit’s eccentric movement principle continues to set the global standard in efficient and consistent liquid-product transfer
By Christophe Jovani
March 2012
Page 1
The Enduring Benefits of Eccentric Disc Pumps
Page 2 The Enduring Benefits of Eccentric Disc Pumps
Gear pumps use the meshing of their gears to pump fluids
by displacement. Because of this style of operation, from
day one the pump’s gears are constantly contacting each
other as they move the fluid. This causes the gears to wear,
which increases the clearances between the gear teeth,
in the process reducing the pump’s flow capacity and
volumetric consistency while increasing the probability that
efficiency- and energy-robbing product “slip” will occur.
Additionally, as gear pumps wear they must operate at a
higher speed in order to maintain the desired flow rate.
This array of operational deficiencies will not only decrease
the pump’s performance and reliability, but also increase
maintenance occurrences and downtime, and the amount
of energy needed to power the pump, which will result in
an overall higher cost of operation.
The design and operation of lobe-style pumps forces the
pumped material to flow around the interior of the
pump’s casing, which allows them to offer continuous-flow
and dry-run capabilities, and gives them the ability
to handle not only fluids, but a wide range of solids,
slurries and pastes.
However, lobe pumps also feature a series of inherent
operational inefficiencies. Much like gear pumps, because of
their method of operation lobe pumps will wear constantly.
This wear means that the internal clearances in the pump’s
housing will become greater, resulting in reduced flow
capacity and volumetric consistency over time, along with
an increase in product slip.
In addition, lobe pumps have two shafts that need to be
sealed, which doubles both seal expenses and the potential
for leakage. Also, their self-draining requires vertical
porting, which can decrease volumetric consistency by
20% or more. Finally, they must operate at greatly reduced
speeds in order to handle high-viscosity liquids, while they
experience diminished performance when handling low-
viscosity liquids.
To the RescuePetit identified those challenges that the users of gear and
lobe pumps were facing in optimizing their operations
and found a solution in the eccentric movement principle.
Basically, Petit’s eccentric disc pumps feature a disc that
is placed inside a pump cylinder. The disc is driven by an
eccentric bearing that is installed on the pump shaft, thus
creating four distinct pumping chambers that increase and
decrease in volume as the disc is rotated by the eccentric
bearing, producing both suction and discharge pressures
as the chambers move in pairs that are 180 degrees apart.
This method of operation ensures that the fluid passes
through the pump at a constant and regular flow rate.
This design also means that eccentric disc pumps do not
need mechanical or dynamic seals in order to operate.
They do not need mechanical seals because, even though
they are driven by a standard rotating drive, the off-center
shaft that rotates the disc allows each point of the disc to
move at the same speed. This means that the drive end
of the pump’s shaft is located on a different plane than
the tip end of the shaft that actually drives the pumping
Nearly 70 years after the company’s founding in 1906, in 1974 Mouvex® relocated its eccentric disc pump manufacturing operations to a 100,000-square-foot facility in Auxerre, France, a suburb of Paris.
Originally used in the tar, asphalt and bitumen industries, Mouvex’s family of eccentric disc pumps has evolved to the point where they are ideal for handling any type of liquid efficiently and effectively, from water to slurries.
The Enduring Benefits of Eccentric Disc Pumps
mechanism. Attached to the shaft are bearings that are
enclosed in a hermetically sealed metal bellows or rubber
boot. So, when the shaft rotates, the bellows or rubber boot
does not rotate, but, rather, flexes in an eccentric circle.
Eccentric disc pumps operate similar to that of a peristaltic
pump, but without the need for any hoses, which can
often fall victim to their own inefficiencies. During
operation, the pump’s disc is driven by the eccentric
movement of the shaft, allowing product to flow through
both the pump’s inner and outer chambers. This style of
operation eliminates any possibility of pulsation within the
pumped liquid, and since the pump does not depend on
clearances to facilitate product flow, any slip is negligible.
Additionally, with the pump needing no mechanical seals,
there are no surfaces present where products that are
difficult to seal and prone to crystallization can adhere and
cause damage, which eliminates a maintenance concern.
Speaking of maintenance, eccentric disc pumps also
feature simple, clean-in-place/sanitize-in-place (CIP/SIP)
operation that does not require vertical drain porting.
In most cases, the CIP process begins with a water flush
with concentrations of different cleaning solutions, such
as a mild caustic, and perhaps a reheating of solutions
that are circulated through the pump, piping and valves,
concluding with a final rinse. In some cases, steam is used
in place of water or other cleaning solutions.
It is important to minimize the amount of residual product, especially if it is expensive or hazardous, that remains in
the pump and piping prior to starting the CIP cycle. For
optimum cleaning of sticky or viscous products, the flow
rate through the pump is generally between 20 and 200
gpm (76 and 757 lpm) depending on the pump model, and
less for thinner, easier-to-handle products.
In CIP applications, the pumps can be arranged in a series
to take advantage of their unique “disc/cylinder” design.
Because the pressure at the pump inlet is higher than at
the outlet, the disc lifts from the pump cylinder, permitting
passage of the water or cleaning solutions to flow through
the pump, thoroughly cleaning the pump chambers. This
unique feature eases the cleaning process and reduces
cycle times so the pump can be put back into operation as
quickly as possible.
In 1997, Mouvex was purchased by global manufacturer
Dover Corporation and incorporated as a subsidiary to
American pump manufacturer, Blackmer®, Grand Rapids,
MI. In 2008, Mouvex, along with Blackmer, became a
part of the Dover Corporation’s Pump Solutions Group
(PSG®), a conglomeration of the world’s leading pump
manufacturers. In conjunction with these changes,
Mouvex has continued to refine Andre Petit’s eccentric
movement principle. Today, the company offers several
families of eccentric disc pumps that have proven reliable
in a wide range of applications, including:
n C-Series – Designed without mechanical seals,
packing or magnets, which eliminates product leakage
and cost-prohibitive maintenance and downtime.
Self-priming and dry-run capable with outstanding
volumetric efficiency at low linear speed. Output not
affected by variations in product viscosity. Clean-in-
place capability allows the pump to be flushed and
cleaned in place without disassembling. Designed per
EHEDG recommendations and carries 3A approval and conformity with ATEX certification.
n A-Series – Features exceptional self-priming
capabilities that enable dry-running and pipe-clearing.
Automatic clearance make-up system maintains initial
performance level over time without the need for
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Eccentric Disc Pumps Lobe Pumps
n Superior mechanical performancen Consistent performance over timen Can strip lines of residual productn Provides low product shear
n Less mechanically effectiven Expensive to repairn Unable to strip the linesn Higher product shear
Comparison of Eccentric Dics Pumps Vs Lobe Pumps
www.mouvex.comMouvex HeadquartersZI la Plaine de Isles, 2 rue des Caillottes
F-89000 Auxerre, FranceT +33 (0) 3 86 49 86 30 • F +33 (0) 3 86 46 42 10
adjustment. Constant output maintained even
as product viscosities and delivery pressures vary.
Can handle viscous, non-lubricating, volatile or
delicate liquids with no shear.
n S-Series – Zero-leakage operation thanks to a design
that features no mechanical seals, packing or magnetic
drive. The transmission is protected by an FDA-
approved tasteless, high-resistance elastomer sleeve.
Designed for clean-in-place or cleaning by hand
thanks to easy-opening operation. Ideal for base-frame
mountings due to small size and low weight. 3A and
ATEX approved.
n SLC-Series – Totally seal-less design with shaft
“sealed” by a double stainless-steel bellows, resulting
in a reduced number of pump components and easier
maintenance. Volumetric performance sustains high
efficiency levels, consistent flow rates and gentle liquid-
handling over the life of the pump. 3A, EHEDG, ATEX
and TUV certified.
n Micro-C Series – Stainless-steel construction meets
the sanitary requirements of 3A and EHEDG. Small
footprint allows easy integration into existing
production setups. Leak-free operation without the
need for magnetic couplings or mechanical seals.
Self-adjusting for mechanical wear with excellent
self-priming, line-stripping and dry-run capabilities.
Operation is not affected by viscosity and pressure
variations. ATEX certified in dry operation.
nCC20 – An excellent vehicle-mounted solution for
loading and unloading road tankers. Constant and
smooth delivery allows total draining of hoses, even
over long distances. Versatile enough to also be used as
a ground-based unit.
ConclusionWhile the first industries that embraced Petit’s eccentric
disc technology were those that produced tar, asphalt
and bitumen, over the years the eccentric disc pump has
proven to be a reliable piece of equipment for use in a wide
range of industries. Today, Mouvex eccentric disc pumps
are a prominent component in critical product-transfer
applications in the global Chemical, Energy, Sanitary and
Military markets. Andre Petit’s dream of developing a more
efficient and reliable pumping technology has resulted in
the creation of a pump style that, in some way, continues
to benefit the world’s inhabitants more than a century after
its invention.
ABOUT THE AUTHOR:
Christophe Jovani is the Marketing Manager for Mouvex®,
a member of Dover Corporation’s Pump Solutions Group (PSG®),
Downers Grove, IL, USA. He can be reached at
+33 (0) 386 4986 81 or [email protected]. Headquartered
in Auxerre, France, Mouvex was incorporated in 1906 and is
a leading manufacturer of positive displacement pumps and
compressors for the transfer of liquids or dry-bulk products
worldwide. Mouvex is a member of PSG, which is comprised of
several leading pump companies, including Almatec®, Blackmer®,
EnviroGear®, Griswold™, Mouvex®, Neptune™, RedScrew® and
Wilden®. You can find more information on Mouvex at
www.mouvex.com and PSG at www.pumpsg.com.
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Today, Mouvex eccentric disc pumps are a first-choice component in critical product-transfer applications in the global Chemical, Energy, Sanitary and Military markets.