Features of operation of surface pumps. Pumping station: connection diagrams and do-it-yourself installation procedure Water pump surface installation

Arrangement of water supply and sewerage in a private house is a hackneyed question, but relevant for the majority. Having become accustomed to the benefits of civilization, we can no longer imagine a full life without them. Comfortable living in a private house is now completely dependent on water supply and sewerage. At the same time, constantly carrying water in buckets is hard and exhausting work. What can we say about trying to take a bath in such spartan conditions! But, fortunately, now it’s easy to solve the problem of water supply to the house - just install a pump. The selection, installation and connection of a surface pump are discussed in detail in this material.

Why is it needed?

The name of the surface pump speaks for itself - this device does not require immersion in water to function properly. It is installed “on land”, and the liquid is supplied to the pipes using a flexible hose leading from the pump into the water. You should also install .

Thanks to easy access to the device, the surface pump is easy to maintain, which is what attracts owners of private houses.

On a note! Such installations are quite weak and cannot lift water from great depths. The maximum is only about 10 m. If the well on the site is deeper, then you will have to buy a more powerful pump - for example, a submersible one.

A conventional surface pump works like this: at the end of the suction conduit, which is not lowered into the water, a vacuum is created, and the liquid begins to rise through the hose due to the difference in pressure at both ends. Interestingly, at the suction site this figure is 760 mmHg. Art. in a complete vacuum and replacing mercury with water, we get a height of 10.3 m. So it turns out that in a complete vacuum the liquid can only rise by this amount. You should also take into account the presence of certain losses due to friction against the walls of the conduit - thus, we get a distance of only about 9 m. As a result, the actual operating height of the surface pump is very small - about 8-9 m.

When choosing a pump, it is also important to take into account the distance from the well to the pump itself, as well as the position of the water pipeline. That is, it is worth remembering that 4 m of the horizontal part of the hose will be equivalent to 1 m of water rise.

The surface pump works as follows.

1. or the hydraulic accumulator connected to the pump, due to the design, will be filled with water to a certain level.
2. The pump's automation will turn it off after the water reaches a certain level. The water supply will stop.
3. When the water from the tank is used up, the pump will automatically turn on again and refill the accumulator completely, and then stop.

If you need to pump water from a shallow well or a nearby reservoir, then purchasing a surface pump will be the best option for organizing an autonomous water supply to your home. Moreover, such a device is installed very simply and does not require special operating conditions.

Advantages and disadvantages

What else are good about surface pumps? The advantages of these devices are the following:

1. Small dimensions - such a pump can be installed almost anywhere, it will not disturb anyone, and does not require the creation of a massive foundation.
2. Cheap - you can buy such a pump for little money.
3. The uninterrupted operation life is about 5 years - this is a decent operating time for such a device. If you handle the unit with care, it will last longer.
4. The payback period for the equipment is quick – a maximum of two years.
5. Installation of such a pump is simple and quick. The only difficulty is the need to securely attach cables and hoses to it.
6. The device is economical - it does not consume a lot of electricity.
7. If necessary, shutdown occurs automatically - there is no need to guard the operating device.
8. In repair, as in operation, a surface pump is very simple and cheap. And it’s convenient - you don’t even need to take the hose out of the water.
9. Safety is another advantage of the installation. The electrical cable in the device does not come into contact with water.

But a surface-mounted pump also has its drawbacks, which you should know in order to assess the need to purchase this equipment and the justification of the monetary costs.

1. Low power - such a device can only lift water from a depth of no more than 8-10 m.
2. Filters must be installed.
3. Before turning on the pump, it must first be filled with water.
4. The equipment creates a lot of noise, so it is not recommended to install it in a residential area of ​​the house.
5. The surface pump can only be used in a warm room.

As we see, the equipment has more advantages than disadvantages. The main thing is that the disadvantages should not be the determining factors, and then you can safely buy this equipment.

Centrifugal surface pump "Vodoley BC-1.2-1.8U1.1"

Types of surface pumps

There are three types of surface pumps - centrifugal, ejector and vortex. They differ from each other in design features and performance characteristics.

Table. Types of surface pumps.

Based on what was written above, it can be noted that it is best to purchase a centrifugal pump. This is the best option. Let's take a closer look at its structure: a pair of disks are installed on the gear shaft inside the mechanism. A small hole is made in one of them, connected to the free space between these parts. In this gap there are plates inclined at a certain angle - they create special channels from the center of the free space to the edge. These “passes” are connected to a diffuser, which in turn is connected to a supply conduit. And the suction hose is connected to the disk hole.

The inter-disk free space and the suction hose are filled with water, then the gearbox starts up, and the vane plates begin to rotate and push out the water. This process occurs due to centrifugal force. As a result, a discharged space is created in the center, and at the edges and in the diffuser, on the contrary, the pressure increases. To even out this “skew”, the system will strive to equalize the indicators and begin to pump water. This is how this setup works.

Attention! Such pumps are usually not used independently - they are part of the design of the pumping station. This system includes a control unit and a hydraulic accumulator.

To ensure that the pump lasts as long as possible, they create. The installation pumps water as needed into the storage tank. This allows you to significantly save equipment resources, since the pump will only turn on when the hydraulic accumulator is empty. In addition, frequent switching on of the pumping unit entails high energy consumption. And thanks to the arrangement of a pumping station, it is possible to save resources, money and provide the house with a certain supply of water.

A hydraulic accumulator as part of a pumping unit is a volumetric tank that has a membrane or bulb inside, around which there is a certain level of pressure. That is, the water entering this container is under pressure. The design of the pumping station also includes a pressure switch, which will force the equipment to start and stop on time. And the pressure gauge installed in the system will help you keep track of the pressure level. Connects all the parts into a single organism “five-outlet” - a special fitting with five outlets.

Pumping station with built-in ejector

Prices for a pumping station

pumping station

How to choose?

How to choose a surface pump? First, you should get acquainted with certain criteria, knowing and evaluating which, it will not be difficult to make a choice.

1. Installation performance. For watering a garden, a model with an indicator of 1 m 3 / hour is sufficient, but for the water supply system of a house you will have to make certain calculations taking into account the number of people living in it and the number of water consumption points (faucets, washing machines, etc.). If 4 people live in a house, then the pump must have a capacity of at least 3 m 3 / hour.
2. . The length of the hoses, their position (vertical, horizontal), and the depth of the well or borehole are taken into account.

   

3. Water pressure at the most extreme point of water consumption, furthest from the pump, must also be taken into account. It must be sufficient for normal operation. The pressure is usually indicated in the documents for the equipment and is measured in meters or bars. You can determine the indicator by calculating the entire distance that the water will have to travel. Every 10 m the pressure decreases by 1 m.
4. Mains voltage. This is also an important indicator that affects the performance of the pump. If the voltage in the network drops, the pump will not be able to operate at full capacity, which means it will not provide the house with the required amount of water.

It is worth remembering that to organize an autonomous water supply system at home, you should buy a more powerful pump than for simply watering a greenhouse. Therefore, it is important to clearly know for what purpose the equipment is being purchased.

You may be interested in information about why you need

Most owners of country houses and summer cottages install a well or a well on their plots, which allows them to always have the required amount of water available both for domestic needs and for watering green spaces. If the depth of the source does not exceed 10 meters, surface-type pumps are used to equip it. Various models of such devices offered by modern industry differ in both design and technical characteristics.

It is very important to know how to select surface pumps for specific applications in order to ensure the required efficiency of a given equipment. In addition, in order for a surface-type pump to function without emergency situations for a long time, it is necessary to put it into operation correctly, as well as ensure its regular maintenance.

Surface pumps are perhaps the most popular type of equipment that solves the problem of water supply to a garden plot and a country house.

What are surface pumps?

During operation, surface pumps are not immersed in the pumped liquid medium - they are located on the surface of the earth, in close proximity to the water supply source. Most often, pumping devices of this type are used to pump water from well sources, since the depth from which they can effectively pump out a liquid medium is no more than 10 meters.

A surface pump is also used for pumping water from the basement or cellar of a house, as well as for pumping liquid media from wells located on quicksand. Surface water pumps are easy to operate. To carry out maintenance of such devices, there is no need to remove them from the pumped medium. They are also distinguished by their versatility: they are equally successfully equipped with water supply and drainage systems, as well as drainage systems and systems with the help of which watering of green spaces on a personal plot is carried out.

Design features and varieties

The design of any surface water pump is based on three components:

1. power unit, the basis of which is the drive electric motor;
2. a pressure unit, through which a vacuum and pressure zone is created in the working chamber of the device;
3. a block with the help of which the power and injection units of the hydraulic machine are controlled.

According to its design and operating principle, a surface water pump can be one of the following types of devices:

• vortex type equipment;
• centrifugal surface pump;
• pumping units equipped with an external ejector.

A vortex-type surface water pump is an inexpensive and compact hydraulic machine that is able to generate a water flow with a pressure exceeding that of centrifugal-type models. Meanwhile, an inexpensive vortex-type surface pump has a low efficiency (about 45%); devices of this type cannot be used for pumping a liquid medium that contains a large amount of sand or other solid insoluble inclusions. The basis of the design of surface pumps of this type is an impeller equipped with a large number of blades, which form the flow of the pumped liquid medium with the required characteristics.

A surface centrifugal pump is a more expensive device that effectively copes with pumping a liquid medium in the flow of which there are air bubbles and plugs that can lead to the formation of pulsation processes. Despite the fact that pumping devices of this type are characterized by a fairly high efficiency, they also cannot cope with pumping liquid media characterized by a high level of contamination. The main working element of centrifugal surface pumps is the impeller, the rotation of which is transmitted through a rotor connected to the shaft of the drive electric motor.

A surface pump for a well or well, equipped with an external ejector, is practically not used today, since it has been replaced by a submersible type pump, which is characterized by higher productivity.

Centrifugal pumping equipment

Surface (external) centrifugal pumps, as mentioned above, pump a liquid medium due to the rotation of an impeller equipped with special blades. The blades of this wheel, driven into rotation by the electric motor shaft, create a vacuum in the central part of the working chamber, which ensures the suction of the liquid medium into it through the inlet pipe, and increases the pressure of the pumped liquid at the walls of the chamber, which helps push water into the pressure line.

Surface centrifugal pumps are capable of pumping a sufficiently large volume of liquid per unit of time, but are not able to generate a large pressure of the pumped liquid medium.

Most often, surface pumps of the centrifugal type, due to the above characteristics, are used to equip irrigation systems for green spaces. Another critical disadvantage of pumping devices of this type is that they produce a lot of noise during operation.

Vortex pumping equipment

Surface pumps, classified as vortex pumps, are used primarily for wells and shallow wells. A surface electric pump of this type is capable of creating the strongest possible pressure of the pumped liquid (compared to other external pumping devices). This is ensured by the fact that the liquid medium sucked from the well or well into the internal working chamber of the hydraulic machine is subject to turbulence, which significantly increases the energy of the flow.

Surface pumps of the vortex type, the basis of the design of which are the impeller and helical grooves on the walls of the internal working chamber, although they are characterized by a lower suction capacity than models of the centrifugal category, are capable of forming a fluid flow moving through the pipeline system under significant pressure.

Advantages and disadvantages of external pumps

The most significant advantages of surface pumps for a private home or cottage are:

1. compact size and light weight;
2. affordable cost (when compared with the price of other types of pumping devices);
3. ease of installation, which can be performed even without special knowledge, skills and experience;
4. ease of operation and maintenance;
5. the ability to work with a water layer whose thickness does not exceed 60 cm (if the layer of liquid medium located in a well or well is characterized by such a small thickness, then the use of submersible pumps is not possible);
6. air cooling rather than liquid cooling;
7. the possibility of forming a flow of liquid medium characterized by significant pressure;
8. fairly high efficiency;
9. no need to supply power directly to the water intake area;
10. high reliability and long service life;
11. high stability of operational parameters even if there are air pockets in the serviced pipeline system.

Naturally, pumping devices installed on the surface of the earth also have a number of disadvantages, including:

1. fairly high sensitivity to the presence of various contaminants in the pumped liquid medium;
2. restrictions on the depth of a well or well (this parameter cannot exceed 9–10 meters);
3. a sharp decrease in efficiency and reliability when used in conjunction with an external ejector;
4. high noise level (up to 50 decibels);
5. the need to fill the pressure line with water before starting work.

When choosing a surface pump for a summer house or country house, you should first decide on the main tasks for which such equipment is purchased. When choosing a pump for outdoor use, you should focus on a number of basic technical parameters of such a device.

For watering the garden plot

If you plan to use a surface-type pump to water a summer cottage or a plot of a country house, then the main attention should be paid to the following parameters of the selected equipment.

• Productivity measured by the volume of water that the device is capable of pumping per unit of time. In order for a garden pump to provide high-quality watering of green spaces, it is enough that its productivity is about one cubic meter of water pumped per hour of operation.
• The depth of the well or well, with a bark pump for the garden will pump out water. You should also take into account the vertical-horizontal ratio, which should be 1:4. So, if a surface pump is used to pump water from a depth of two meters, it must be eight meters away from the water supply. If the total length of the vertical and horizontal parts of the pipeline is more than 12 meters, to equip such a system, pipes with an internal cross-section increased by 1/4 inch should be used.
• When choosing the pressure value that a surface-type pump can provide, you should focus on the most distant point of water intake.

For home water supply

Surface-type pumps are also successfully used to ensure the operation of autonomous water supply systems for residential buildings. When choosing a surface pump that you plan to use to solve such a problem, you should focus on the total volume of water consumption at all water intake points, as well as on the pressure of the fluid flow that must be provided at such points. To select a surface pump according to these parameters, you can rely on the following data.

• To provide water to a house inhabited by 4 people, a pump is needed with a capacity of 3 m 3 /hour.
• To provide water to a house in which two families live, a pump is needed with a capacity of 5 m 3 /hour.
• A four-family house needs a pump with a capacity of 6 m 3 /hour.
• In order to provide water to a personal plot, the productivity of the selected surface pump should be increased by a value equal to 1 m 3 / hour.

If a surface-type pump is operated in regions where dry periods are common, its capacity should be increased by another 40–50%.

Surface pumps for wells allow you to pump out water from a shallow depth, which is important for owners of country houses and summer cottages.

We will talk about the main characteristics and features of these devices, and also show how to install a surface pump in a well.

Surface pump

Device and purpose

Surface pumps operate on the principle of suctioning water by creating a vacuum at the end of a suction hose, the other end of which is lowered into the water. Thus, a pressure difference arises at different ends of the hose, and with full vacuum at the suction it will amount to atmospheric pressure, that is, about 760 mm Hg.

If we replace the mercury column with a water column, then the height of such a column will be 10.3 meters, which means that with a complete vacuum on the suction side, the water can rise no more than 10.3 meters.

Taking into account losses due to friction of water against the walls of the pipe and incomplete vacuum in the system, the maximum height of water lifting of such a pump will be no more than 9 meters, and if we take into account the horizontal part of the suction pipe, it turns out that the actual working height will be 7 - 8 meters.

Important!
When calculating parameters, the distance from the surface pump well should be taken into account.
The following formula would be appropriate here:
Y = 4(8-X), where Y is the length of the horizontal part of the pipe, X is the suction height.
That is, four meters of horizontal part is equivalent to one meter of rise.

Important!
From the above calculation we can conclude that the surface pump is designed to lift water to a height of up to 8 meters.
This allows this device to be used for collecting water from open reservoirs, shallow sand wells and wells.

By design, external pumps are divided into three main types:

1. Vortex. The most compact and inexpensive devices are capable of creating a fairly high pressure in the system, but they have a low efficiency of no more than 45%. They are used mainly for irrigation and pumping water from flooded premises, but the low efficiency and low reliability do not allow this type of equipment to be recommended as a permanent unit for an autonomous water supply system;
2. Centrifugal. More expensive and reliable devices that create, although less than vortex, but quite sufficient pressure to ensure the operation of the water supply system. They have a high efficiency rate - up to 92% - with sufficient reliability for constant use, which allows the use of this type of equipment in the operation of water supply pumping stations;
3. Ejector. They have two water circulation circuits: in the first circuit, liquid is supplied to the ejector nozzle, where, due to the Bernoulli effect, a pressure difference is created and water is sucked in from the external environment - the second circuit. This solution allows you to lower the ejector to a depth and solve the issue of limiting the suction height, but now for these purposes they use more efficient submersible units, which have a higher price/quality ratio.

As you can see, centrifugal pump designs turned out to be the most practical, so we will dwell on them in more detail.

The centrifugal unit is designed quite simply:

• Two disks are rigidly fixed on the gearbox drive shaft, in the center of one of which there is a hole;
• The hole communicates with the inter-disk space, where inclined plates are soldered in, creating channels from the center of the space to its edges, which are connected to a collector container (diffuser) communicating with the supply hose;
• A suction hose is connected to the hole in the center of the disk;
• If you fill the suction hose and the inter-disk space with liquid and set the gearbox drive in motion, then the blades inclined in the opposite direction of rotation will begin to push water from the center to the edges of the space between the disks due to centrifugal force;
• As a result, a vacuum will be created in the area of ​​the center of the wheel and the suction hole, and an area of ​​​​high pressure will be created in the area of ​​​​the edges and the diffuser connected to the discharge hose;
• Under these conditions, the system will strive for equilibrium, and water will be pushed out by pressure from the storage tank at the edge of the wheel into the discharge hose, while a vacuum will arise in the center of the wheel, and liquid from the suction hose will rush there under the influence of atmospheric pressure.

As a result, continuous circulation is created and water is pumped from one point to another, which is what was required to be achieved. However, to operate in an autonomous water supply system at home from a well, a surface unit is not used independently, but rather a so-called pumping station is assembled, about which more details are given in the next paragraph.

Pumping station

For normal operation of the surface pump as part of the water supply system of a residential building, it is connected to a storage tank and an automatic switching control system. This is necessary in order to reduce the number of unit starts per unit of time.

The fact is that when the power is turned on, peak current values ​​appear on the motor winding, which are called inrush currents. These currents have a destructive effect on the device, therefore, from the point of view of the operating life of the electric motor, it is much better for it to operate with the smallest number of start-off cycles.

On the other hand, constant operation of the pump is unnecessary and economically unprofitable, since it consumes a considerable amount of energy and drains the well. Obviously, it is necessary to create a certain supply of water and pressure in the system, which will cover the constant switching on and off of plumbing fixtures and taps, and only when this pressure drops below certain values ​​will the pump turn on and restore the supply.

Accordingly, when a certain peak pressure value in the storage tank is reached, the pump will automatically turn off.

This is how we come to the design of the pumping station, and its main parts are:

Important!
With a sufficient volume of the storage receiver, the system will turn on the pump quite rarely, which will significantly extend its service life, as well as extend the service life of motor starters and terminal blocks.
In addition, peak pressure values ​​and their characteristic water hammer will not occur in the water supply system, which will protect the shut-off valves and pipe connections.

Related articles:

Connecting the pumping station to the well

If you are planning to connect a surface pump to a well with your own hands, our step-by-step instructions will help you:

1. The pumping station (or a separate pump) is installed on a solid, stationary base and the legs are secured with bolts or anchors. It is recommended to place a rubber mat under the installation to reduce the vibration activity of the device;

1. The outlet (supply) hole of the pump is connected to the inch outlet of the five-pin fitting using a hose or directly;

1. The accumulator tank is also connected to the inch outlet of the fitting using a soft hose or directly;

1. The remaining inch hole of the fitting is connected to the internal water supply pipe of the house;

1. A pressure gauge is screwed to the ¼-inch hole on the fitting;

1. The pressure switch is connected to the remaining unoccupied last hole of the fitting;

1. The pump suction port is connected to the water intake pipe;

The figure shows where the pump and power supply are connected to the relay.

1. The working space of the pump is filled with water through a special hole in the housing and the device is started;

1. The taps in the house are closed and they wait for the tank to be filled. When the tank is full and the pump is turned off, the cut-off pressure is measured using a pressure gauge;
2. Then open the taps and drain the water until the pump turns on again. The switching pressure is detected;
3. Finally, the obtained pressure values ​​are checked with the receiver’s passport data and, if necessary, the pressure switch is adjusted.

It is necessary to connect a surface pump to draw water from the well. But let's start with a little description and background. There is a house in which water supply is implemented according to the diagram below:

More details: There is a well. A submersible pump is lowered into it, which draws water from the well into a settling tank located in the house. This is necessary so that sand and other debris settle in it. Water is pumped into the tank automatically. For this purpose, a float sensor is installed in the tank. Next, through a filter system, the pumping station draws water from the sump and supplies it under pressure to the water supply circuit of the house. The pressure created by the pumping station is sufficient for simultaneous operation of the washing machine, dishwasher and shower.

Everything in this scheme is good. Except for one thing - the submersible pump may break. It's one thing for something like this to happen in the summer. And it’s completely different when in winter it’s minus forty outside, you have to dismantle the well, remove the pump, install a new one, and then insulate everything again. In general, there is nothing pleasant about this. This happened in this case too...

To prevent a repetition of the above situation in the future, it was decided to install a surface pump instead of a submersible one, because If equipment fails, you won’t have to wait for a thaw to replace it.

What you will need

• surface pump (in this case Kraton pwp-370);
• hose;
• adapters G1-herringbone 3/4;
• check valve G1();
• clamps.

Surface pump connection

Here is the culprit of winter well removal:

After dismantling it, we have a hose with a diameter of 3/4 in our hands. We insert the adapter G1-herringbone 3/4 into it.

And we fix the connection for reliability with a clamp.

Next, screw the check valve onto the threaded connection. It would be a good idea to use flax to improve the quality of the threaded connection.

After this, we lower the hose with the check valve into the well.

Let's move on to the equipment. The Kraton pwp-370 surface pump has two threaded holes with a diameter of 1 inch each. One of them is for water intake, and the other is for supply (in our case, for filling the settling tank). To connect hoses with a diameter of 3/4 to it, you will need two adapters G1-herringbone 3/4.

We screw the adapters into the pump. Be sure to use flax or other sealant for threaded connections.

We connect the hoses. One coming from the well, the other from the tank.

We fix the hoses using clamps.

The surface pump is ready to draw water from the well. But before you start pumping water, the system should be prepared for the first start.

First start of the surface pump

It is very important that there is water in the system. If it is not there, the surface pump will not pump water. Moreover, when working dry, it can overheat and fail before it has had time to work. This means that before starting the equipment, the pump itself and hoses should be filled with water. For these purposes, there is a plug on its body. Unscrew it and fill it with water.

It’s rare that someone manages to fill the circuit with water the first time. Especially if there are reverse slopes. As a result, water is pumped intermittently with low pressure or does not touch at all. To completely eliminate air from the circuit, you should start the pump briefly, and after turning it off, slightly unscrew the air release plug. This manipulation should be repeated until the water flows with uniform, good pressure without “spitting.” At this point, we can assume that the connection of the surface pump to the well is completed.

You can’t do without a pump in a country house or country house, especially if you have an artificial pond or well. The choice of this equipment depends on many nuances; each model has its own characteristics, advantages and disadvantages. At the same time, you can familiarize yourself with the features of individual types of products in advance, which will greatly simplify the purchasing process. The self-priming surface pump deserves special attention.

The main distinctive feature of the product is indicated by its name itself. It can be easily operated on the surface of the earth, without requiring immersion in liquid. Water is pumped using hoses connected to the device - intake and supply. The first is used to lift liquid from the source, and the second is used to pour out.

The surface self-priming pump is widely used for pumping water from open sources (ponds, swimming pools), shallow wells (up to 7 m), and watering agricultural plantings. It can also act as a separate element of a pumping station and serve to pump water into a storage tank.

Using a Surface Pump

The material for the manufacture of such devices is cast iron, stainless steel or plastic. The latter is preferable, since plastic models are lightweight, have good moisture resistance and resistance to corrosion processes. Moreover, their cost can be an order of magnitude higher than that of analogues made of cast iron and steel.

Device with plastic housing

Advantages and disadvantages of surface pumps

The principle of operation, the material of manufacture, the permissible operating conditions - these and many other points determine the advantages and disadvantages of self-priming surface-type pumps.

The advantages of such devices for pumping water include:

• Ease of maintenance – cleaning, repairs. Sometimes it is not so easy to remove the submersible model from the well to determine the failure.
• Mobility. The compact size and light weight of the products make it easy to change their location on the site. However, you should not move the device too far from the water source.
• Easy to install. You just need to connect the hoses and securely install the device on the surface of the earth.
• Relatively low price. For comparison: submersible models used at great depths have greater power, moisture resistance and strength. Due to this, their price can be 2-3 times higher than the price of surface pumps.
• Possibility of using them as part of pumping stations.

Pumping station based on a surface-type device

Despite these advantages, self-priming surface-type pumps also have a number of significant disadvantages.

• Small suction depth (up to 7 m). Equipping the product with an ejector will increase this figure.
• A small amount of water pressure, which is enough to water the garden plot, but not always enough to provide high-quality water supply to the house.
• Sensitivity to contaminants in water.
• Some models are too noisy.

How does a self-priming pump work?

Based on the principle of operation, surface self-priming pumps are usually divided into centrifugal and vortex pumps.

Operating principle and features of the centrifugal device

The operation of centrifugal models is based on the movement of the impeller (impeller) inside its housing and the creation of centrifugal force that propels water.

Scheme of operation of a centrifugal pump

Sequentially it looks like this:

• The body of the device is completely filled with water to displace air from it.
• When it is turned on, the impeller begins to move, creating a centrifugal force that pushes water to the outlet.
• In this case, a vacuum is created in the area of ​​the intake hole, which provokes the suction of a new volume of liquid.

Filling the working chamber with water before turning on the device

Please note: if there is only one impeller, then they speak of a single-stage water movement system, if there are two or more - of a multi-stage one.

Centrifugal models are valued for their high efficiency, the ability to pump large volumes of water (relevant for home water supply), compact size and simplicity of design. They are also characterized by less sensitivity to contamination than their vortex counterparts.

The most significant disadvantage is the inability to operate the device with air. The impeller cannot generate suction force from the air in the chamber. Moreover, if an air lock forms in the pump “sleeve”, the process of pumping water may stop.

How does a surface type vortex pump work?

Vortex pumps are designed to work with slightly contaminated water without abrasive particles, which contribute to their rapid wear and breakdown. However, they are significantly superior to centrifugal models in that the suction force can be generated from a mixture of air and water or air alone.

These devices are much more suitable for irrigation of land than for supplying water to a home. Moreover, they can be successfully combined with centrifugal models, forming a multi-stage water pumping system.

As for the design of such a product, the rotating element is no longer the impeller, but the impeller - an impeller enclosed in a ring. When operating in the pump chamber, air is removed through the outlet pipe, and the water separated from it is forced out to the supply hose due to the movement of the impeller.

This creates a water recirculation effect, causing a vacuum in the suction chamber. This provides an influx of new fluid volume. The ejector works on a similar principle.

Self-priming models with ejector

An ejector is a simple device that allows you to significantly increase the suction depth of the pump. Its work is based on the separation of water flows and its recycling. Part of the water that rises from the source returns to the ejector and flows out at high speed through its tapered nozzle.

It enters the mixer, where it creates a vacuum that ensures the flow of liquid from the suction chamber. Then there is a standard movement of water through the device and its outflow through the supply hose.

The ejector can be built-in or external. In the presence of the first, the recycling process occurs directly in the device, which allows you to maintain its compact dimensions. However, when such a product operates, there is a lot of noise that prevents its use in the house or in its immediate vicinity. The best option for placing a pump with a built-in ejector is a separate building.

The built-in ejector allows you to increase the suction depth by only 3-5 meters. An external device increases this figure to 30-50 meters, but at the same time the efficiency of the pump decreases. It also requires the installation of an additional pipe to ensure recirculation.

Video: operating principle of the ejector

Thus, a surface self-priming pump is quite capable of satisfying domestic water needs. If choosing a device, connecting it to a pumping station or installing an ejector causes difficulties, you can always contact specialists. Qualified assistance in this matter is the key to the longevity of the pump and your peace of mind.