progressive cavity mud pump free sample

The Liberty Process LL8 Progressive Cavity Pump is ideal for abrasive pumping applications such as drilling fluids with sand and grit common in fracking operations. As a Mud Pump, the LL8 Series is a popular model on many mobile pumping rigs in use today. Replacement mud pump parts are available as well from our stock and work on other popular manufacturers models.

LL8 parts are direct drop in aftermarket replacements that work with the *Moyno® L8 series, the *Tarby® TL8 series and *Continental® CL8 Series*. The Liberty unit is a low-cost, maintenance free, dependable drop-in replacement progressive cavity unit.

The Liberty LL8 is a standard flanged pump design manufactured with cast iron or 316 stainless steel pump casings designed in 1, 2, and 3 stages for 75, 150 and 225 psi discharge pressures and a flow rate of 18 up to 100 GPM.

The LL8 is a modular design with simple hardened pinned joint drive assembly. LL8 Rotors are typically hardened tool steel or 316 stainless steel with a hard chrome plating for long life in abrasive pumping applications.

All other wetted parts are either carbon steel or 316 stainless steel. Stators are available in many elastomer materials such as Buna Nitrile, Natural Rubber, EPDM and Viton. The standard seal design is a set of gland packing with a lantern ring set and flush connections. Mechanical seal options for this progressive cavity pump are readily available.

The LL8 represents one of the most popular progressive cavity pumps available for the transport of drilling mud with easily replaceable in-stock parts.

The Liberty Process LL12H Progressive Cavity Pump is an ideal industrial-sized progressive cavity pump for abrasive pumping applications and high-viscosity industrial chemical applications like thickened grease, scum and slurries. The LL12H Flow rate (65 gallons/100 revolutions) of 123 GPM up to 380 GPM and represents one of our most popular heavy duty models of Progressive Cavity Pumps for Industry currently carried in stock by Liberty Process.

The Liberty LL12H Series PC Pump is a standard suction flanged pump manufactured with cast iron or 316 stainless steel casings and designed in 1 and 2 stages for 75 and 150 psi discharge pressures.

Stators are available in many elastomer materials such as Buna Nitrile, Natural Rubber, EPDM and Viton. The standard seal design is a set of gland packing with a lantern ring set and Flush Connections. Mechanical seal options are readily available. The Liberty unit is a low-cost, maintenance free, dependable drop-in replacement pump which will give you the service you need at a price you can afford.

The Liberty LL12H Progressive Cavity Pump parts are direct aftermarket replacements that work with the *Moyno® L12H Series, *Tarby® TL12H Series and Continental® CL12H Series.*;

A progressing cavity pump is a type of positive displacement pump and is also known as a progressive cavity pump, progg cavity pump, eccentric screw pump or cavity pump. It transfers fluid by means of the progress, through the pump, of a sequence of small, fixed shape, discrete cavities, as its rotor is turned. This leads to the volumetric flow rate being proportional to the rotation rate (bidirectionally) and to low levels of shearing being applied to the pumped fluid.

These pumps have application in fluid metering and pumping of viscous or shear-sensitive materials. The cavities taper down toward their ends and overlap. As one cavity diminishes another increases, the net flow amount has minimal variation as the total displacement is equal. This design results in a flow with little to no pulse.

A progressing cavity rotor and stator can also act as a motor (mud motor) when fluid is pumped through its interior. Applications include directional well drilling.

The progressing cavity pump normally consists of a helical rotor and a twin helix, twice the wavelength helical hole in a stator. The rotor seals tightly against the stator as it rotates, forming a set of fixed-size cavities in between.

The principle of this pumping technique is frequently misunderstood. Often it is believed to occur due to a dynamic effect caused by drag, or friction against the moving teeth of the screw rotor. In reality it is due to the sealed cavities, like a piston pump, and so has similar operational characteristics, such as being able to pump at extremely low rates, even to high pressure, revealing the effect to be purely positive displacement. The rotor "climbs" the inner cavity in an orbital manner (see pump).

At a high enough pressure the sliding seals between cavities will leak some fluid rather than pumping it, so when pumping against high pressures a longer pump with more cavities is more effective, since each seal has only to deal with the pressure difference between adjacent cavities. Pump design begins with two (to three) cavities per stage. The number of stages (currently up to 24) is only limited by the ability to machine the tooling.

The rotor takes a form similar to a corkscrew, and this, combined with the off-center rotary motion, leads to the alternative name: eccentric screw pump.

Different rotor shapes and rotor/stator pitch ratios exist, but are specialized in that they don"t generally allow complete sealing, so reducing low speed pressure and flow rate linearity, but improving actual flow rates, for a given pump size, and/or the pump"s solids handling ability.

In operation, progressing cavity pumps are fundamentally fixed flow rate pumps, like piston pumps and peristaltic pumps, and this type of pump needs a fundamentally different understanding than the types of pumps to which people are more commonly introduced, namely ones that can be thought of as generating pressure. This can lead to the mistaken assumption that all pumps can have their flow rates adjusted by using a valve attached to their outlet, but with this type of pump this assumption is a problem, since such a valve will have practically no effect on the flow rate and completely closing it will involve very high pressures being generated. To prevent this, pumps are often fitted with cut-off pressure switches, rupture discs (deliberately weak and easily replaced), or a bypass pipe that allows a variable amount of a fluid to return to the inlet. With a bypass fitted, a fixed flow rate pump is effectively converted to a fixed pressure one.

At the points where the rotor touches the stator, the surfaces are generally traveling transversely, so small areas of sliding contact occur. These areas need to be lubricated by the fluid being pumped (hydrodynamic lubrication). This can mean that more torque is required for starting, and if allowed to operate without fluid, called "run dry", rapid deterioration of the stator can result.

While progressing cavity pumps offer long life and reliable service transporting thick or lumpy fluids, abrasive fluids will significantly shorten the life of the stator. However, slurries (particulates in a medium) can be pumped reliably if the medium is viscous enough to maintain a lubrication layer around the particles and so protect the stator.

Specific designs involve the rotor of the pump being made of a steel, coated with a smooth hard surface, normally chromium, with the body (the stator) made of a molded elastomer inside a metal tube body. The elastomer core of the stator forms the required complex cavities. The rotor is held against the inside surface of the stator by angled link arms, bearings (immersed in the fluid) allowing it to roll around the inner surface (un-driven). Elastomer is used for the stator to simplify the creation of the complex internal shape, created by means of casting, which also improves the quality and longevity of the seals by progressively swelling due to absorption of water and/or other common constituents of pumped fluids. Elastomer/pumped fluid compatibility will thus need to be taken into account.

In 1930, René Moineau, a pioneer of aviation, while inventing a compressor for jet engines, discovered that this principle could also work as a pumping system. The University of Paris awarded René Moineau a doctorate of science for his thesis on “A new capsulism”. His pioneering dissertation laid the groundwork for the progressing cavity pump.

SEEPEX supports the purification and clarification of wastewater with state-of-the-art wastewater pump technology. These pumps can be used in sludge dewatering, sludge drying and incineration, sludge treatment and mixing, or optimized digestion processes. Thus, they can contribute to much more efficient, cost-reduced and simplified processes.

SEEPEX wastewater pumps are particularly economical, as they convey highly dewatered cake and sludges with virtually no restrictions on viscosities or abrasive materials. Slurries with dry matter contents of up to 45% are transported effortlessly.

Our standard wastewater pumps are robust and can be used to reliably pump primary sludges or thickened sludges. For discharge from thickeners or silos, our hopper wastewater pumps (optionally with screws and blades) are suitable for conveying dry masses onward without disruptive bridging.

Drilling mud is most commonly used in the process of drilling boreholes for a variety of reasons such as oil and gas extraction as well as core sampling. The mud plays an important role in the drilling process by serving numerous functions. The main function it is utilized for is as a lubricating agent. A large amount of friction is generated as drilling occurs which has the potential to damage the drill or the formation being drilled. The mud aids in the decrease in friction as well as lowering the heat of the drilling. It also acts a carrier for the drilled material so it becomes suspended in the mud and carried to the surface.

Using a Moyno progressive cavity pump, the drilling mud with suspended material can be pumped through a process to remove the solids and reuse the cleaned mud for further drilling.

The wide variety of applications that can be accommodated by Moyno progressing cavity (PC) pumps has been highlighted by an offshore application. Ten of Moyno’s 2000 Series pumps have been ordered for a new fleet of offshore supply vessels that will be used to service drilling rigs worldwide.

The 2000 Series pumps will be fitted to ten new HOS MAX 320 supply vessels that Mississippi-based VT Halter Marine is building for Hornbeck Offshore. The pumps will transfer up to 24-pound (HH kilogram) liquid mud to and from the vessels, which will be off-loaded when they reach the drilling rigs.

This is a very demanding application for any pump. Drilling mud is a very aggressive substance that can have high solids content, so the pumps must be able to withstand this.The ability to operate at sea was another important consideration. For example, centrifugal pumps require a fairly stable level of pumped media to work efficiently. The motion of the sea can cause the mud levels in the vessels to fluctuate constantly and this would have reduced the efficiency of a centrifugal pump, leading to longer off-loading times and expensive delays.

However, the progressing cavity action of the Moyno pumps isn’t affected by these changing mud levels and they can work perfectly well in these circumstances. This allows the vessel operator to accurately predict the time needed for off-loading and get the vessels heading back to shore for the next load as soon as possible, without any costly delays.

The Moyno 2000 gear joint pump offers best value and application versatility. The proprietary gear joint design effectively handles radial and thrust loads for maximum

In addition to these predictable off-load times, our 2000 Series pumps are also well-proven in this type of challenging duty. They offer the high volume and high pressure capabilities which the customer requires, plus the ability to operate in reverse so that mud levels in the tanks can be adjusted to add extra stability while the vessels are at sea.

Moyno’s high-performance 2000 Series pumps offer an outstanding combination of low maintenance, minimal downtime and long service life, which all combine to create a low cost of ownership. Their proprietary 2000 Series gear-type universal joint design minimizes wear and accommodates both radial and thrust loads with ease. This allows the pumps to handle abrasive materials with over 80 percent solids, while still maintaining a steady and consistent flow. The 2000 Series range also offers performance capabilities to 4500 gallons (17,034 liters) per minute, with pressure to 1500 psi.

Both cast iron and stainless steel models are available, with a choice of materials and coatings for rotors and stators, to suit individual applications. The 2000 Series pumps also have a low running speed capability which extends both the maintenance intervals and the overall working life. That pays particular dividends on an application like this where the pumped media is so abrasive.

The pumps will transfer mud at volumes up to 1000 gallons (3785 liters) per minute, handling pressures of 200 psi. The order was secured through Moyno’s partner company, Chemetec Engineered Equipment. Other pumps in the Moyno range offer proven solutions for many other oil and gas applications, such as multiphase fluid transfer, lease automatic custody transfer, crude oil transfer and produced water handling duties.

Chip Strickland is techincal services manager for Moyno, a brand of National Oilwell Varco. Moyno manufactures progressing cavity pumps, grinders, screens and aftermarket spares and services, across a broad spectrum of industrial sectors including water and wastewater, oil and gas, chemical, pulp and paper, food and beverage and agriculture. For more information, visit www.moyno.com or call 877.486.6966.

The new generation of FLUX progressive cavity pump VISCOPOWER F 570 for Industry & Hygienic with planetary gear is suitable to pump thin to medium viscous media. The ...

The Eccentric screw pump HD-E-SR in the Pure version transfers the advantages of the Drum pump for viscous media quite simply to the high-viscosity range. The positive ...

The B70V SanitaryPlus food pump is a powerful positive displacement pump for heavy-sensitive, viscous and viscous media up to the limits of flowability. It pumps liquid foodstuffs, ...

The B70V SanitaryPlus food pump is a powerful positive displacement pump for heavy-sensitive, viscous media with and without fiber or solids content up to the limits of flowability. It pumps ...

Reduce maintenance and sanitisation time at your facility with the SaniForce Drum Pump, designed for easy cleaning with quick tri-clamp connections, minimal moving parts and easy transferability.

... NEMO® progressing cavity pump is especially interesting where pumps are installed in wear intensive applications requiring more service and maintenance work. Up to 66 ...

... or abrasive, with the NEMO® BY progressing cavity pump even difficult substances can be conveyed gently and with low pulsation, regardless of fluctuations in pressure and viscosity. In ...

... SY progressing cavity pumps are used in demanding applications for continuous, pressure-stable, gentle and low-pulsation conveyance as well as dosing in proportion to speed in nearly ...

ViscoTec dispenser 3VMP15, as a volumetric dispensing pump for larger volumes, ensures smooth and reliable product supplying of abrasive, high-filled or shear sensitive material - with a repeatability of +/- 1 %!

ViscoTec dispenser 3VMP22, as a volumetric dispensing pump for larger volumes, ensures smooth and reliable product supplying of abrasive, high-filled or shear sensitive material - with a repeatability of +/- 1 %!

... slurries that jam up lobe pumps or progressing cavity pumps with ease. It also imparts very low shear forces to the pumped product, far lower shear than lobe pumps ...

Mag Drive series are the first progressing cavity wobble stator pumps to offer magnetic drives. The proprietary, magnetic coupling design performs well in hazardous applications ...

Compact C Pump delivers reliable performance to the maximum duty requirements of your application in a compact package. Features include suction lift capability up to 28 feet, positive ...

For nearly 50 years, versatile L-Frame pumps have stood the test of time meeting thousands of application challenges with performance-enhancing, cost-saving features.

Thanks to the hopper and auger, the KST progressive cavity pumps are suitable for pumping high viscosity products, doughs, pastes and liquids with suspended particles.

... manufactured by Nova Rotors, is a range of progressing cavity pumps. This pump is completely reversible and has a wide pumps range. It features a one ...

The hopper pump from Nova Rotors s.r.l. come with a feeding conveyor that is ideal for transferring products that are highly viscous, and are characterized with a high solid percentage that starts at 17%. This device ...

The N series is a flanged pump that is ideal for use in heavy-duty operations such as transporting raw, primary, secondary, and thickened sludge before the filter press. The unit has a rated flow capacity lesser than ...

Mag Drive series are the first progressing cavity wobble stator pumps to offer magnetic drives. The proprietary, magnetic coupling design performs well in hazardous applications ...

Its solid drive shaft makes the 70500 the pump of choice for handling anything with a tendency to set up -- and eventually build up -- in a hollow-shaft model. That includes thermosetting adhesives, concrete, ...

With seepex pumps of the BN range, the drive is flange-mounted directly on the pump. The combination possibilities were expanded and enhanced in dialog with well-known drive manufacturers. The design ...

... gentlest, most hygienic food sanitary pump. It"s been especially designed for food applications, featuring a patented body design developed using advanced computational fluid dynamics. This progressing ...

Investing in our progressive and smart control technology significantly boosts the performance and efficiency of Vogelsang machines and systems. It captures and continuously monitors key parameters like the capacity or throughput rate, rpm, pressure and power consumption. The control detects malfunctions early, and rectifies them by intervening appropriately. The integrated communication interfaces like ProfiNet and OPC UA can exchange data with other systems or a superordinate control in real time.

Progressive cavity pumps, also known as PC pumps, progressing cavity pumps, eccentric screw pump and mono pumps are a type of rotary positive displacement pump designed for the conveying of liquids and sludges from 1cst to 1Million. They handle not only viscous fluids and solids but also gassing or multiphase liquids containing gas slugs typical during crude oil extraction.

The volume of liquid pumped is proportional to speed providing a linear predictable pumping rate across a range of pressures. This technology delivers one of the highest flow and pressures available from a positive displacement pump being up to 600M³H and 48bar, with efficiency ranging from 55% to 75%. This technology is most suited for fluids more viscous than 5cst.

The design consists of a motor at the drive end which is connected to a gearbox as pc pumps operate at low rpm compared to centrifugal pumps. The output shaft from the gearbox connects to a rotor via a universal pin joint which rotates a metallic rotor within a rubber stator. Stators contain cavities, and the rotor pushes fluids through the cavities in a slow rotating fashion.

A pumps pressure generating ability will depend on the number of cavities within the pump, with high pressure designs often consisting of more than one stator and rotor. Each rotor will typically produce 6 bar enabling pressures up to 48 bar to be achieved through its modular design.

This design of pump is better suited for viscous lubricating fluids, which can contain solids. Short stator life can be experienced with abrasive slurries at which point a peristaltic pump can be a preferred option. Eccentric Screw Pumps viscosity handing is unrivalled, and they are usually specified when there are no other suitable options.

Stator designs consist of two types - equal and non-equal walled. Equal walled stators ensure a lower starting and running torque, lower pulsations and reduced power consumption, high volumetric pumping efficiency, and lower replacement costs. Materials are usually types of rubber being NBR, FKM but not PTFE meaning solvents cannot be handled.

·Oil & Gas – Cutting Transfer, Drilling Mud transfer and recovery, Separator Feed, Crude Oil Transfer, MOL (Main Oil line Pump), Multiphase transfer and injection in remote areas.

Low shear -Ensures gentle handling of the most difficult to pump fluids such as resins, viscous foods, oil and water emulsions without change in consistency to the liquid. They are often use in oily water separators as the design ensures oil droplets remain intact and was rated by SPE (Society of Petroleum Engineers) in Paper SPE18204 as the preferred pump to use for oil droplets which were disturbed the least during handling and a comparison of lobe, vane and screw technology.

Reversible – Units are reversible with reduced output pressure as standard meaning hoses can be emptied, or if blockages are encountered pump can be reversed to assist with clearing. It also enable the pump to be versatile for situations such as tanker loading and offloading.

Wide fluid handling capabilities –Designs can handle viscous liquids, large solids, abrasive materials, fibrous solids and gas slugs without issue making it one of the most versatile pumps available. This design has Unparalleled Viscosity handling viscosities from 1cst to 1Million means there are no comparable pumping technologies.

High Accuracy –Due to flow being directly proportional to pump speed, and due to its cavity design, it enables flows to be very predictable enabling it to be used in metering and dosing applications

Hopper Pump –A pump is fitted with a hopper of various designs, designed for viscous liquids, materials containing high amounts of dry matter, large solids requiring breaking up and materials which plasticise

Multiphase Design -Baseplate mounted unit for multiphase boosting, with accessories allowing pump to handle viscous oil, gas slugs, sand and water, with automatic remote operation.

Bridge Breaker –For the breaking up of large solids within dehydrated sludge. Motorised paddles rotate within the hopper ensuring particles are broken into sizes which can be accommodated by the pump preventing blockages

Motorised wheel – Feeding of liquids with high dry solid content and materials which plasticize into the main pump. When materials such as liquid mortar, resins, mud, blocks of fat, or butter are pumped they can plasticise meaning they change shape rather than break up. To ensure they are fed into the rotor and stator, a motorised wheel ensures materials are broken up when other technologies may mean materials clog.

Liquid injection port –Typically used for the biogas sector, this unit has a separate injection port for accepting liquid manure which is combined with materials in the inlet containing high dry solids content (such as digestate, straw, corn, grass, rye, vegetable and food waste ) ensuring pumpability.

PC Pump curves are different to a centrifugal curve as it is linear demonstrating the units ability to handle liquids of varying viscosities with little impact on pump performance, with the bottom axis being speed rather than flow as flow is proportional to speed. Unit speed is much lower than centrifugal, operating from as little as 50rpm

Not suitable for solventsAll metal parts means solvents can be transferred, although some designs may have bearings within liquids and should be avoidedAll metal parts means solvents can be pumped.

When the stator is lined with an appropriate elastomer, the pumps resist abrasion and are able to produce fluids containing high concentrations of sand and other solids. They also operate within a wide temperature range; some PCPs operate reliably at temperatures up to 120°C [250°F]. The pumps do not contain valves or reciprocating parts that may clog or lock up and they are designed to limit the rate of shear, or relative motion between adjacent layers of the flowing production fluid. This shear rate control helps limit agitation, fluid emulsification and instances of foaming that might cause processing problems downstream. At the surface, the drive system has a simple design with a small footprint and low profile, and it emits low noise levels.

However, PCPs have an upper production rate limit of approximately 800 m3/d [5,040 bbl/d] for large-diameter pumps and significantly less for small-diameter pumps. Current PCPs have a true vertical well depth limit of about 2,000 m [6,500 ft].

In addition, these pumps are sensitive to the downhole fluid environment; for example, the stator elastomer has a tendency to swell or deteriorate when exposed to certain fluids, such as those used in acid stimulation treatments. PCPs may exhibit volumetric efficiencies of less than 30% in wells producing substantial quantities of gas and greater heat retention in the pump, which may lead to elevated elastomer temperatures and reduced pump life. Paraffin control can also be problematic in waxy crude production scenarios because the rotational movement of the rod string precludes the use of scrapers for paraffin removal.

Other threats to PCP run life include rod string and tubing failures in directional and horizontal wells and increased incidents of leakage caused by excessive vibrations in high-speed applications. When PCPs operate without fluid, the pump stator deteriorates rapidly.

Operators choose PCP systems for wells characterized by high-viscosity fluids and high sand cuts. In heavy oil wells, where produced fluid viscosity ranges from a few hundred to more than 10,000 cP [10 Pa.s], PCPs may be deployed as one part of a production system. These systems may include streamlined rod strings that have minimal flow restrictions, injection of diluents such as light petroleum products or water to reduce fluid viscosity and heated or buried surface flowlines. The optimal selection of elastomer type and pump size may be a trial-and-error process of varying pump parameters and tracking system performance.

PCP systems are also used to lift production fluids in wells that have highly variable downhole temperature profiles and those containing elevated levels of carbon dioxide [CO2], methane [CH4], hydrogen sulfide [H2S] or aromatics and paraffins. Any of these factors, alone or in combination, can impact pump operating life by attacking the elastomeric material in the stator. Operators must therefore carefully prescreen elastomers to select the material that exhibits the best performance for the conditions expected.

PCP systems are a common lift method for dewatering coalbed methane wells. Produced water from these wells typically contains high concentrations of suspended sand from hydraulic fracturing, coal particles and dissolved solids. Although these pumping systems can handle the majority of particles, pumping efficiency drops in the presence of coal particles that are 20 mm [0.8 in.] or more in diameter; such particles can become lodged in the pump and cause increased operating torque, stator tearing or pump seizing. Slotted pump intake or tailpipe assemblies can be installed to capture large coal particles before they enter the PCP while allowing fines and water to pass. To prevent gas ingress into the pump, which might lead to heat generation and pump burnout, the pump intake is typically located below the perforations or near the bottom of openhole well completions.

Surface applications of PCPs include transfer of multiphase fluids from wells to collection stations and transport of crude oil from onsite storage tanks to offsite storage facilities. Because PCPs exhibit a high tolerance for rocks, cuttings, sand and other solids commonly found in drilling mud returns, they may be used to move drilling mud from storage tanks into centrifuges and to feed drill cuttings from the shale shaker into the cuttings dryer.

Operators use PCPs to pump produced water to hydrocyclones or flotation units and to transfer skimmed oil from these units to storage tanks. They may also be used to return fluid to upstream separators to extract more oil before final disposal. During hydraulic fracturing operations, PCPs are employed to dose chemicals and proppants into the fracturing fluid that is pumped downhole.

Because PCP stators routinely wear out faster than rotors, the industry is focused on stator design innovation. In addition to more robust elastomeric materials, PCP providers have developed all-metal stators. Such a stator would enable the PCP to withstand the rigorous operating conditions of enhanced oil recovery methods that expose the pump to temperatures as high as 350°C [600°F], to steam and to produced fluids that have diverse fluid viscosities, pressures and flow rates.

To address premature pump failures caused by insufficient fluid levels, recent innovations address pump automation and optimization. Known as pumpoff, a lack of fluid in the pump causes increased internal temperatures and elastomer burnout, which forces operators to replace pumps sooner than would otherwise be necessary.

Solutions to pumpoff-related failures range in complexity and scalability and depend on the needs of the well. Simple variable frequency drives (VFDs) may be deployed to control motor speed and torque by varying input frequency and voltage, which helps regulate the temperature, pressure and flow rate of fluids moving through the pump. More sophisticated optimization systems are available that integrate a VFD with a control system that remotely monitors pump performance and production through surface and downhole sensors. Such control systems can automatically route commands to the VFD to fine-tune pump performance, thus optimizing flow rates and reducing pump failures and well interventions. Developments such as these promise to extend the applicability of progressing cavity pumping and help operators maximize well production.

Progressive cavity pumps are designed for a minimum of maintenance, which usually includes routine lubrication and packing adjustment. If mechanical seals are used, cooling/flushing water flow should be checked. The pump is one of the easiest to work on. The main elements are very accessible and require few tools to disassemble and reassemble on-site.

During the last 25 yr, there has been a trend towards the use of smaller diameter rotors and longer sealing lines in an attempt to reduce wear and improve pump efficiency. Some manufacturers have changed to this geometry, producing rotor/stator designs that maintain pump capacities and pressure capabilities while reducing the rotor eccentricity sliding velocity and increasing the length of the sealing line, providing a more “straightline” flow through the pump.

Progressive cavity pump stators are usually molded to size for a custom fit. Some stators are molded in long tubes and cut to length. Other forms of stators are a two-part design. The casing is generally made of steel and the elastomer, with seals at both ends, vulcanized to it. The inner shape of the elastomer comes from a metal core placed in the center of the casing before vulcanizing. Stators of this type usually have tighter dimensions at the ends.

Destruction of the pump stator by dry running occurs when loss of lubrication of the pumped fluid causes excess friction and temperature on the surface of the stator. It is the most common cause of pump failure.

Presence/absence sensors protect pumps by detecting the absence of liquid flowing into the suction port. If supply fluid is not detected for a preset period of time, the system deactivates the pump motor starter or other critical process equipment. This sensor is reliable protection against dry running because it can stop the pump before dry running occurs (Fig. 7).

Nonintrusive pressure sensors at the pump outlet are an effective way to prevent dry running. Pressure detection over the entire pipe circumference ensures that coatings, settled material, or bridging does not affect pressure readings. As an added feature, a liquid-filled gauge allows visual monitoring of pressure.

Plant Engineering magazine extends its appreciation to Bornemann Pumps, Inc., and Moyno, Inc. for their assistance in the preparation of this article. The cover picture was taken with the cooperation of Shanley Pump & Equipment, Inc.

The M range metering progressing cavity pump series is designed specifically for dosing any kind of liquid. Dosing pumps are feature reversible flow, excellent self-priming rate, and low-shear pulsation-free pumping.

Sydex has the perfect solution for small, sterile pumping applications. The Sydex M Range progressing cavity pump gives you perfect control over flow rates, using its on-board inverter with speed ranges from 0-1000 rpm. With its gentle low-shear ability, this positive displacement pump can handle pressures of up to 36 bars with little impact on flow.

The M range is the ideal metering progressing cavity pump for many different applications: Waste water treatments (Polymers, flocculants); Chemical industry, (Cosmetics, Dyes, Paints, Inks, ) plus many sampling & premixing applications.

Progressive cavity pumps are among the rotating positive displacement pumps: That is, they handle liquids by conveying them into a conveying chamber first and then displacing them from there. The conveying movement is created by a rotating shaft (in contrast, for example to the reciprocating pump, where the piston moves in a straight line). This shaft, called the rotor, oscillates against a fixed stator. Due to the turning, spiral geometry of the two components, conveying chambers (also called cavities) are created, in which the medium flows from the pump inlet to the pump outlet. While the rotor is made of a very hard material (usually metal, for special applications also ceramic), the stator is elastic and normally made of an elastomer.

The consistency and viscosity of the fluid handled are irrelevant for the flow rate with progressing cavity pumps: The quantity transported is determined only by the speed. Combined with a frequency converter, the pump capacity can be controlled easily and precisely. The possible precision is five to three percent; small dispensers can even achieve one percent.

Funnel pumps with special screw conveyors and so-called bridge breakers are suitable for media containing large amounts of dry material. For optimal product supply, the medium is handled in a conical tamping area with a transport screw. Spoked wheels that act on the medium reliably prevent bridge formation in the pump shaft.