A screw pump, or as it is also called, a screw pump, is one of the varieties of rotary gear pumps. The pressure of the pumped liquid in it is created due to its displacement by one or more helical metal rotors rotating inside the stator.
A screw pump can be easily obtained from gear pumps by increasing the angle of inclination of the teeth in them and reducing the number of gear teeth.
The principle of operation of the screw pump
Due to the movement of liquid between the surface of the housing and the helical grooves along the axis of the screw, it is pumped. The screws enter with their protrusions into the grooves of the adjacent screw and thereby prevent the liquid from moving back.
Scope of screw pump
It is used for pumping steam, gas, their mixtures and liquids of varying degrees of viscosity.
For the first time, screw pumps were introduced into production in 1936. Their simple design allows you to work, including in the presence of mechanical impurities with viscous fluids at pressures up to 30 MPa. Similar Features important in solving various practical problems.
Screw pump units are used in large quantities in coal bed methane wells to pump out water from there. They are also suitable for water, oil and other gas well applications.
Design features of screw pumps
In order to improve the quality of seals and reduce the number of leaks in screw pumps, conical or cylindrical elastic casings are used. The conical screw is securely pressed by the spring and pressure from the pumped liquid, which significantly reduces leakage. However, pumps with a flexible casing can withstand much less pressure than their counterparts with metal casings. A rigid housing is also suitable for a pump with a conical screw.
The most common type of screw pumps are three-screw pumps.
In practice, they have found the widest application.
To their characteristic advantages relate:
- uniform supply of liquid (gas, steam);
- the ability to pump liquids with solids without damaging them;
- ability to self-soak up liquids;
- without a lot of injection stages, it is possible to get a high outlet pressure;
- low noise level during operation;
- good balance of mechanism.
The disadvantages of this type are:
- high cost and complexity of manufacturing the pump;
- inability to adjust the working volume;
- inadmissibility of use idle (without pumped liquid).
The principle of operation that screw pumps have
Modern screw pumps, according to the principle of operation, are positive displacement rotary hydraulic machines. The working bodies are a screw pair with internal gearing. The movable element of the working pair, the screw (rotor), makes planetary motion in the holder (stator).
The clip has an internal helical surface with a pitch twice the pitch of the screw. Being in constant contact, the holder and the screw form several closed cavities along the length of the screw - holder. When the screw is rotated, the cavity on the suction side increases in volume and a vacuum is created in it, under the action of which the cavity is filled with the transported medium. Further rotation of the screw moves the cut-off volumes of the transported medium towards the discharge side.
At a set screw speed, the speed of the transported medium and the productivity that screw pumps have during operation are constant, because invariably the flow area of the screw and clip.
Screw (screw) pumps are positive displacement pumps, the design of which allows you to create a stable pressure and allow you to adjust the performance without losing the nominal pressure. Screw pumps have a long service life, high efficiency, are reliable and versatile when working with a wide range of tasks.
A screw screw pump is a device in which the pressure of the impelling material is created by the displacement of the pumped liquid by one or more helical metal rotors that rotate inside a stator made of an appropriately shaped elastomer.
The production of screw (screw) pumps requires precise manufacturing of parts, such as a working pair - a rotor and a stator, in the development and manufacture of which special high-precision equipment is used. Computer calculation using special programs is a guarantee of high quality, which increases the life of the equipment and reduces energy consumption during the operation of the pump.
Screw pumps are used to work with thick, viscous and viscous masses, as well as for pumping low-viscosity products. Depending on the design of the pump and its material design, it is possible to pump resins, pastes, oils, food products, abrasive or even corrosive liquids so that the particles that make up their composition are not crushed or destroyed by mixing with the base liquid.
Screw pumps are designed to work in food production, mining or chemical industry, wastewater treatment in the municipal and production area, petrochemical industries, pumping out sludge deposits, for work in gas and oil production, shipbuilding, wherever reliable and simple equipment for continuous operation is required, unpretentious in operation and subject to simple maintenance and repair. The applications for this type of pump are almost endless, thanks to its special design, the materials used, technical features and special operating mechanisms.
Advantages of screw pumps
- The most uniform liquid supply among all positive displacement pumps. No pulsation;
- Pumping liquids containing solids, impurities and abrasives, multiphase media with a high gas content;
- Pumping products with low and high viscosity (1 mPa*s to 5 million mPa*s);
- Pumping aggressive (pH from 1 to 14) and toxic media;
- Screw pumps are self-priming;
- The pressure does not depend on the speed of the pump (capacity control);
- Silent operation;
- Ease of maintenance.
The screw pump (VH), which is a liquid transfer device, was developed in the early 1920s for pumping viscous liquids and solutions. From the very beginning, screw pumps have been widely used in a wide variety of conditions in various industries (chemical, food, metal, paper, textile, tobacco, waste processing and oil).
Since the first serious attempts to use PCPs for artificial lift in the early 1980s, they have been gradually introduced into the oil industry.
By 2003, PCPs were operating in a wide variety of conditions and completions in more than 40,000 wells worldwide, from Alaska to South America, from light oil and coalbed methane production in Russia's Nizhnevartovsk and Novokuznetsk to Australia, from remote mineral springs in mountains of Japan to onshore and offshore wells in Africa and Indonesia. Below are the standard options and conditions for the use of screw pumps:
heavy oil
API Gravity Absolute Viscosity 500 - 50000 cP
Sand content up to 50%, reduced to 3-5% with a stable flow rate
Medium density oil
Density in degrees API 18 - 30
Absolute viscosity CO2 and H2S limits
light oil
API Gravity >30
Limitation on the content of aromatic hydrocarbons
Temperature limits
Water
Coalbed Methane Dehydration (CBM)
Dehydration of natural gas
Water wells
- Residential heating
- Industrial springs of mineral waters
Water injection - flooding
Screw pump systems have a number of distinctive features which may make them preferable for artificial lift over other available technologies. Here are the most significant of these features:
- The efficiency of screw pump systems is 50 - 70%
- Low capital and energy costs
- Possibility of pumping liquids with high level viscosity, high content of solids and free gas
- Low internal shear rate gradients limit fluid emulsification
- No valves or reciprocating parts to prevent blockages, gas locks or worn components
- Simple installation and operation, minimal maintenance required
- Small dimensions and low noise level of the drive unit at the wellhead.
PCP systems have a number of specific application limitations. The main of these limitations are the capacity, liquid lift height and the compatibility of rubber parts with pumped liquids. The following is a summary of the restrictive application conditions and operational problems associated with the use of HV systems.
- Productivity: 1-800 m3/day (5000 barrels/day)
- Liquid lifting height: 3000 m (9800 ft)
- Temperature: 150°C (300°F)
- Tendency for permanent damage to elastomeric parts when running the pump without liquid, even for a very short time.
- Exposure to certain liquids causes swelling and deterioration of the elastomeric material
The use of advanced equipment and materials can significantly expand the range of application of screw pumps of new models. In many cases, VN is not only the only possible option mechanized operation, but can also become very cost-effective when optimally configured and properly operated.
Basic principles of screw pump operation
The screw pump is a positive displacement pump consisting of two components - a rotor and a stator (Fig. 1). The rotor is in the form of an external helix with the number of starts "n" and is usually made of high strength steel (Fig. 2). The rotor is the only moving part of the pump. The stator is an internal spiral with "n+1" turns (Fig. 3) and consists of a steel casing-pipe with an elastomeric element permanently connected to the pipe walls. The rotor has one pass less than the stator.
When they are assembled together, a group of biconvex cavities, spiraling around the rotor from the outside, stretches along the helix of the pump (Fig. 4). Each cavity is hermetically separated from adjacent cavities by means of sealing lines. Sealing lines are formed along the contact line between the rotor and stator (shown in red) and are important point for effective work pump. Rice. 4 shows two separate cavities on the same stator pitch at 180° to each other in a pump with a single start rotor.
The principle of operation of the screw pump
When the rotor rotates, the cavities constantly open and close and move from pump intake to delivery. The area of the cavity between the rotor and the stator remains constant at any section along the entire length of the pump, which ensures a non-pulsating flow. The cavity volume is defined as the injection area (cavity cross-sectional area) times the stator pitch. The centerline of the rotor is offset from the stator axis by a constant amount called "eccentricity". For a pump with a single pass geometry, the eccentricity is equal to the difference between the large and small diameters of the rotor divided by two. The cavity area of a pump with a single pass geometry is equal to the small diameter of the rotor times 4 times the eccentricity. Cavity volume is defined as a function of cavity area multiplied by stator pitch.
Cavity area = d x 4e
Cavity volume = d x 4e x stator pitch
Pressure characteristic and change in pump flow with pressure change
The nominal differential pressure level of a screw pump is the sum of the nominal pressure levels of each individual stage. Although this is a somewhat arbitrary definition, a step is usually referred to as the length of one stator step. Typically, the nominal pressure level for an individual stage is in the range of 66-100 psi. The combination of a) the maximum pressure level that can be generated in a single cavity and b) the number of cavities in a pump determines its ultimate pressure. The pressure that can be generated in each cavity is a function of the compression fit of the rotor and stator, the physical characteristics of the elastomeric element, the stator pitch length, and the properties of the fluid being pumped. For a screw pump, ceteris paribus, higher pressure for each stage usually means lower stator life.
The most commonly used measurement method operating characteristics pump is a calculation of the volumetric efficiency of a pump, defined as the difference between the pump's initial flow at zero head and the flow at rated head divided by the initial flow at zero head. The difference in delivery levels at zero and nominal head is defined as "change in pump delivery with pressure change". A change in pump flow with pressure change occurs when a high-pressure fluid disrupts the compression fit between adjacent cavities and breaks between the rotor/stator seal line. This results in an overall reduction in the pump delivery rate, which is constant for a given differential pressure.
Screw pump - a pump in which the pressure of the pumped liquid is achieved by displacing the liquid with screw rotors (one or more) that rotate inside the stator of the appropriate shape. By the nature of the impact of the working bodies, screw pumps are volumetric.
Screw pumps are rotary gear pumps and can be made from gear pumps by reducing the number and increasing the angle of the gear teeth.
Types of screw pumps. Single screw, double screw, triple screw.
Single screw pumps– are horizontal positive displacement pumps. The main components of such pumps are a static rubber casing, which has a two-start helical surface and a single-start screw made of metal, which rotates in the casing. During rotation, cavities are created between the screw and the surface of the cage, where the pumped liquid is first sucked in, and then moves along the axis of the screw to the discharge cavity.
Twin screw pumps- are used mainly when pumping sea, fresh and mineral water with an admixture of oil products.
Twin screw oil pumps– are used mainly when pumping fuel oil and other viscous liquids. This type of pumps has a single mechanical seal, a heating jacket, the solid part is made of structural steel.
Three screw pumps– are used mainly when pumping non-aggressive liquids that have lubricity and do not contain abrasive mechanical impurities. The minimum viscosity is limited by the lubricity of the liquid, the maximum by the power of the electric motor and the suction capacity of the pump.
Differences between screw and screw pumps
In one group with screw pumps, screw pumps are often combined, due to the fact that both types of pumps are displacement pumps. However, according to the nature of the impact of the working bodies, screw pumps are dynamic.
The main component of the screw pump is a gerotor (screw) pair, which determines the properties of the pump unit, and also determines the mechanism of its operation. The screw pair consists of a static element - the stator and a moving part - the rotor. The stator is an internal spiral with the number of turns "m+1". This element is made of elastomer and is combined with an iron clip. The rotor is an outer spiral with the number of starts "m". This element is made of steel with or without further coating. The most common classical model are pumps with a two-way stator and a single-thread rotor.
Screw eccentric screw pumps have many qualities that make them indispensable when working with inhomogeneous viscous substances, substances with various impurities, as well as in those areas where it is simply impossible to use other pumping units due to different substrates. These pumps are self-priming and do not require “filling”, in other words, the pumped substance is not a working medium.
Screw eccentric pumps can pump inhomogeneous substances with various impurities. The size of admissible inclusions depends on the size of the closed cavities between a rotor and a stator. One rotation of the rotor corresponds to a certain size of the pumped substance, which allows for fine tuning of the unit. Pumps of this type do not experience pulsations or flow breaks, despite the fact that they are able to withstand any production load at a stable pressure.
Main knots
The design of screw pumps includes such elements as: a drive motor-reducer, an adapter stand, a stator-rotor pair, an outlet pressure pipe, a chamber, a hinge, a shaft sealing device.
Main working part screw pumping unit - screw pair. Inside the stator, made of elastomer, there is a helical metal rotor. The rotational movements of the robot lead to a change in the volume of the cavities inside the pair and the pumped liquid moves along the axis of the pump. The liquid is displaced, and the change in volume in the cavities creates a suction effect.
The principle of operation of the screw pump
The screw pump consists of a rotor (single moving part, number of strokes "m") and a stator (internal spiral, number of strokes "m+1"). The liquid is pumped by moving along the axis of the screw, not being able to move back due to the closed space that the screws create when the screw protrusions enter the grooves of the adjacent screw.
Temperature
Pump stator type determines the maximum level operating temperature liquids.
In addition, the temperature may be determined by the nature of the liquid and the operating conditions of the pumping unit.
Liquid intake parameters
The screw pumping unit is self-priming, even with small delivery volumes, and when working with water with temperatures such as 20 ° C, specific gravity 1 and viscosity level 1 °, the head it creates is 7 m of water column.
Feed characteristics
Progressive screw pumps operate on a positive displacement positive displacement principle, which results in a constant, smooth and fluctuating material flow.
Acceptable fluids
Screw pumps have elevated level chemical and mechanical stability due to the fact that the stator is made of elastomeric material. These pumps are used for pumping any liquids with abnormal (non-Newtonian) viscosity. In addition, screw pumps are able to pump liquids containing solids (except abrasive) without sacrificing performance levels.
Commissioning and adjustment
In order to protect the pump stator, it is necessary to fill the pump with pumping liquid. After that, it is necessary to check that the shut-off valves of the inlet and outlet pipes of the pump are open. If the pump has a motor permanent action with variable speed, to adjust the flow rate of the substance, directly on the pump, you must set the desired flow rate or install a control valve between its inlet and outlet.
Security measures
When turning on the pump, a number of safety precautions must be observed. Starting the pump without filling the medium can lead to deformation of the stator, therefore it is forbidden to turn on the pump without liquid!
You should also avoid adjusting the pump flow rate by closing the supply valve, as this leads to deformation of the drive mechanism and the motor, in case they do not have an overload protection relay.
Key parameters to consider when choosing a pump
In order to select the most suitable pump for your production, a number of key parameters must be considered. First of all, it is necessary to determine the type of installation of the pump and how the pump will be used in the system. In addition, it is important to take into account the flow rate of the pumped liquid (l/min or m³ / h.), The total pressure of the delivery head (bar), as well as the height of the liquid column under the suction nozzle of the pump (NPSN). The list of key parameters to consider when choosing a pump also includes the nature of the pumped substance (chemical composition, density, viscosity, pH, temperature), as well as the level of suspended solids in it and the degree of abrasiveness. In addition, you should consider the level of supply voltage and frequency of the network for connecting the motor, as well as the type of transmission mechanism between the motor and the pump.
Design features
- Durability. The screw is driven by an electric motor and does not come into contact with inner surface pump housing. This reduces friction to a minimum, which ensures a long service life.
- The medium moves in the pump with a constant axial flow direction. Due to this, the pump will deliver the product at the outlet in a smooth flow, without pulsations. The pump has low noise pollution rates. Also, since the moving parts of the pump have low energy, the starting torque and vibration will be low.
- The pump has a high suction capacity.
- In order to ensure safe work pump, motor, piping system, all high power pumps are equipped with safety valves. In the event that the operating pressure exceeds the maximum pressure for which the system is designed (for example, the discharge pipeline), the safety valve and excess product will be directed through the bypass back to the suction chamber.
Advantages of screw pump
Screw pumps have a number of advantages over pumping units of other types. So, unlike centrifugal pumps, screw pumps pump liquid in an even, non-pulsating flow, which allows you not to mix the liquid and preserve its structures.
Unlike impeller pumps, self-priming screw pumps work better with thicker substances, and they also have outlet pressures up to 4-24 bar.
Compared to piston and plunger pumps, the advantage of screw pumps lies in the uniform supply of liquid, as well as the ability to pump mixtures of liquid and solid phases without damaging solids.
Among a number of advantages of screw pumps, it should be noted the high ability of these units to self-priming, as well as the simplicity of the design, which makes maintenance of the pump convenient. The pump consists of three main parts: a stainless screw, a rubber cage and a shaft seal. The liquid supply in the screw pump is proportional to the rotation speed, which provides an easy adjustment of the pump parameters in the presence of a frequency drive. The self-adjusting clearance cage design provides high pump pressure in a small package. With increasing pressure, the gap between the working surface of the screw and the cage remains constant.
Like other types of volumetric pumps, screw pumps have the ability to self-prime liquid from a depth of up to 10 meters. In addition, screw pump units have an optimally balanced mechanism and, as a result, a low noise level. These types of pumps are unpretentious in operation.
Application in industry
The first models of screw pumps appeared in the 1920s and after 10 years were used in production. The maximum operating pressure of pumps of this type can be up to 30-35 MPa.
Screw pumps are used for pumping liquids of various viscosities, gas, steam, and their mixtures. As a result, screw pumps have been widely used in waste processing, tobacco production, textile and paper industries, metal processing, food and chemical industries.
Since the 1980s, screw pumps have been actively used in oil production and are still one of the most promising technologies in this industry.
Screw pumps are used for pumping oil products without mechanical impurities: fuel oil, oil, oil, diesel fuel, paraffin and other liquids with lubricity.
Especially for the food, chemical and pharmaceutical industries, sanitary single screw eccentric pumps have been developed. These products have a classic configuration with articulated sealed units, which ensures the strength of the unit, as well as ease of operation and maintenance.
Screw screw pumps have a wide range of applications due to their design features, the ability to pump dissimilar liquids and other significant advantages over other types of pumps.
Screw screw pump and its features
Such features of the screw screw pump as a valveless design, the ability to change the direction of the flow of the type of liquid being pumped and the direct dependence of performance on the number of engine revolutions allow this type of pump to pump various types of liquids. The list of liquids that a screw screw pump is capable of pumping is constantly growing. The rotor-stator pair plays the role of the main working part of this type of pump. The metal rotor is made in the form of a screw and is located inside the cage, that is, the stator. When the rotor rotates, there is a change in the volume of the cavities within this pair, therefore, the liquid begins to move along the axis of the pump itself by displacement due to the rotation of the rotor. In this case, a suction effect is created in the cavities by changing the volume.
What liquids can a screw pump do?
Able to pump dissimilar liquids, which have a variety of characteristics. It can pump abrasive, emulsion, heterogeneous liquids, as well as liquids containing solid particles. The viscosity of pumped liquids can reach a million centipoise, and the temperature can reach nine hundred degrees in continuous operation and 1200 degrees in intermittent operation.
Where are screw pumps used?
The screw screw pump can be used in various types industry. In heavy industry, these pumps are used to pump anti-corrosion agents, siliceous suspensions. Latex, paints, silicones are also pumped. V Food Industry fermentation wort, honey or vegetable pulp, juices, fats, etc. are pumped. When processing milk, milk, condensed milk, sour cream and yogurt, processed cheeses, etc. are pumped. The screw pump is also widely used in the cosmetic industry for pumping creams, oils and various cosmetic solutions, as well as liquid soaps and shampoos. Screw pumps are widely used in construction for pumping groundwater, transporting river water containing sand. Similar pumps are used in water purification. By means of pumps there is a dosed supply of flocculants, polymers, polyelectrolytes, demineralized water and various chemicals.
According to the site optovik.net
6 March 2013The screw pump ensures uniform pumping of liquids. This type of device is different low level power consumption and high efficiency.
Due to its resistance to different kind environments, screw pumps are used in different areas industries, including various chemical industries.
1 Purpose and design features
The screw apparatus is used in various industries. Apparatuses of this type pump over viscous, dirty and gassed media.
Devices are used in the following industries:
- pharmacology and cosmetic production;
- food industry;
- construction sites;
- chemical industry;
- extraction and processing of oil products;
- Agriculture;
- municipal and housing and communal works.
The units easily cope with anti-corrosion agents, silicone, latex liquids, paints, fats, milk, sour cream, yoghurts, creams, oils, shampoos, liquid soaps, groundwater, sandy water, ethylene glycols, polymers and other chemical liquids of different densities.
The ability to operate in media of various viscosities, the device has due to the valveless design and the ability to change the flow direction.
Unit design:
- body in the form of a cylinder or cone;
- static stator;
- movable metal rotor in the form of a screw;
- rotor shaft;
- connecting pin;
- inlet pipe;
- discharge pipe;
- clutch;
- bed;
- working chamber.
1.1
Screw pumps are self-priming units.
In the mechanism, the pressure of the substance is carried out by displacing the pumped medium with the help of a rotor located and rotating in the stator.
The rotor draws water from the suction pipe while rotating in the stator. The substance moves in a spiral and enters the outlet pipe. Due to the fact that the protrusions of the screws enter into the depressions of the adjacent screw, a closed space is created. The pumped substance cannot be returned back.
1.2 The principle of operation of the screw pump (video)
1.3 Classification of mechanisms
Screw assembly - first of all submersible pump. According to the depth of immersion, they are divided into:
- the deep view is operated at a depth of up to one hundred meters. The design difference of the device is in an elongated screw;
- the standard view is operated in wells and wells up to twenty-five meters deep with sand inclusions.
According to the number of screws, the devices are divided into the following types:
- single screw pumps are a volumetric mechanism of a horizontal arrangement. The device consists of a rubber holder with a two-phase helical surface. The metal screw rotates inside the cage. In the process of rotation, cavities are formed in the cavity between the cage and the screw. The working substance enters the cavity, after which it is transported to the discharge pipe. The single-screw pump transports mixtures with gas inclusions without jerks. The single screw pump is designed for viscous liquids without heating. Differs in simplicity of replacement of working knots;
- twin screw pumps are used to transport water with a mixture of viscous substances such as oil. They are distinguished by a uniform supply of a substance without drops, a suction height of up to eight meters, and the ability to transport a working fluid with different degrees of viscosity. Advantages - no noise, low wear of the mechanism, continuous transportation of liquids independent of pressure indicators;
- three-screw pumps are designed to transport liquid substances without the presence of abrasive.
By appointment:
- the OVN series is used for pumping viscous substances for chemical and food production;
- the VNP series pump over liquids of average viscosity. These are devices for transportation of mayonnaise, varnishes and paints;
- the OHVP series is used for transporting low viscosity liquids from a barrel;
- ONV-food screw pump for pumping pasty products (sour cream, starch, dough, cottage cheese).
1.4 Advantages and disadvantages of screw pumps
Compared to other types of units, screw units have the following advantages:
- ease of maintenance;
- simplicity of design;
- compactness;
- low noise level;
- uniformity of transportation;
- high self-priming function;
- pumping substances with solid particles;
- low percentage of parts wear;
- ease of dismantling;
- reliability at low cost;
- placement in any position.
Compared to work centrifugal pump, lasts longer in conditions of pumping water with sandy inclusions.
The devices also have disadvantages:
- lack of volume adjustment;
- dimensions weight more than other types of pumps.
1.5 Differences between screw and screw devices
Often two types of pumps are confused with each other due to the fact that both types of devices are displacing. By the nature of the operation, the devices differ from each other.
The screw electric pump is distinguished by the ability to work with inhomogeneous substances with inclusions of other substances. These devices do not break the pumped substance. The devices are operated under loads different kind at constant pressure. The pumped liquid is not working.
2 Mounting
The screw type water pump is installed in the following order:
- assembly according to the instructions;
- cable connection;
- water hose connection;
- fixation of hoses with clamps along the entire length;
- installation of a cable for insurance of the unit;
- float installation (if included);
- immersion in the well;
- fixing the device;
- testing.
If there is no knocking and vibration during operation, then the installation was done correctly.
Units should not be installed above the engine due to the ingress of liquid into the engine
2.1 Operating rules
To prevent breakdowns, observe the following rules:
- when pumping liquids of high viscosity, devices with revolutions of three hundred rpm are used;
- when transporting viscous substances, stuffing box seals are used, which must be tightened over time;
- when calculating the resistance for pumping viscous substances, height differences, length and material of the line are taken into account;
- the device is used under the bay to prevent dry running;
- solid inclusions are washed out of the chamber before launch;
- when operating in conditions of fibrous inclusions in liquids, crushers are mounted before entering the device. This procedure prevents fibers from wrapping around the rotor and protects against wear.
2.2 Which device to choose?
Before purchasing, each buyer thinks about which unit to choose. There are not many selection criteria. You must select a device that meets the operating conditions:
- Before purchasing, you need to determine the power of the device. The device should be chosen a little more power than necessary. This will ensure a stable fluid pressure;
- manufacturing material. The material of a quality pump is stainless steel. Units made of other materials will be unreliable and will quickly fail;
- manufacturer's name. When choosing a pump, it is necessary to pay attention to a proven positive side manufacturer. The manufacturer, distinguished by the manufacture of quality goods, provides customers with high-quality devices that serve for a long time.
After choosing and purchasing a unit, it is worth purchasing a repair kit for a screw pump. The repair kit is necessary for quick replacement of the working screw in case of its breakage.
Screw units are simple in design, reliable and durable.
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