How to choose a well pump

Drilling the well itself does not mean completely solving the problem with the water supply at home. Even if very lucky, and a good artesian well possesses certain water pressure, raising its to the surface, it clearly will not be enough to operate an autonomous water supply system. In addition to the fact that the pressure of the water column must ensure the passage of liquid through all vertical and horizontal communication sections, it is necessary to create a mandatory reserve of at least 2.5 atmospheres in order for all household appliances( water heaters, boilers, washing machines and dishwashers and ,n .) Worked correctly. Whatever it was, you can not do without a pump.

How to choose a well pump

Before select a well pump, you need to get the defined representation of the variety of this technique, its structural and operational features, the evaluation criteria of the proposed on sale models. It's a shame to buy a pump that simply does not handle the

with the duties assigned to it. Probably, no less unpleasant will be the situation when is bought completely unnecessary "heaped" model, the functionality of which remains simply unclaimed. And in that, and in another case it's wasted money. In a word, the store needs to send a clear representation with , which pump will be optimal in a particular situation.

To begin with it is worthwhile to understand what kind of well pumps are. First of all , they can be divided into two large groups - surface and submersible.

Surface pumps

Article Contents

• 1 Surface pumps
  • 1.1 Hand pumps
  • 1.2 priming surface pump
  • 1.3 Domestic pumping stations
  • 1.4 Pumping station with an ejector( injector)
  • 1.5 Video: structure and operation of the pumping station
• 2 Submersible
  • 2.1 Vibratory submersible pumps
  • 2.2 Video: vibration pump characteristics
  • 2.3 Centrifugal submersible pumps
  • 2.4 Video: modern wellscentrifugal pumps
  • 2.5 Screw pumps
  • 2.6 Vortex pumps
• 3 What are the criteria for choosing the pump
  • 3.1 Calculator for calculating the required pump head for a system with an accumulating tank
  • 3.2 Calculator for calculating the required pump head for direct water supply to points of consumption
  • 3.3 Calculator calculating the performance of the pump for peak load
  • 3.4 Video: how to approach the selection of pumping equipment

The name itself saysand itself - such a system for pumping water is installed outside the well, on the surface of the earth, and connected to the water horizon by pipes or flexible sleeves.

It would seem that such a scheme of advantages is much more - the mechanisms are always visible, easy to control and periodically serviced, there is no need to extend long power cables to the water intake point, worrying about the quality of the insulation of the wires. Installations - under supervision or located in lockable rooms, that is significantly reduced the likelihood of their theft by intruders.

However, the surface scheme of the installation is fraught with a lot of shortcomings. First of all, it is much more modest indicators for the created head of water - they are simply incomparable with similar parameters of submersible pumps. In addition, we can not exclude the noise factor - the installation of pumping equipment in the house is likely to require a separate room.

What types of pumps can be classified as surface pumps:

Hand pumps

Mention of familiar all from childhood hand pump-columns, probably, many will cause a smile, but meanwhile they are still actively used and, for sure , they have still has a future. Not all situations require a constant inflow of water - there is enough opportunity for of its one-time set( for example, - shared points in populated by points, garden associations, garages and , .).This is the case for hand pumps, which are extremely simple and reliable .

Hand column - such pumps have still not lost relevance

Their working scheme is simple - piston, cylinder and two valves , air and water, working in antiphase. The muscular effort through the lever is transferred to the suction mechanism, which allows you to collect the right amount of water.

Diagram of the device and operation of the hand pump

No dependence on the power source - often this is the only possible variation of the nt for the irrigation organization in the country garden plots where the has not yet been provided with electricity. It is only necessary to drill the not very deep and laborious Abyssinian well. Install such a column - and the question will be solved by .Often such a pump is installed in a common system with an electrical system, via a tee, with the possibility of switching as needed - there will always be a reserve water source in case of problems with electricity supply.

The hand column can be mounted directly to the well( in the case of the Abyssinian well) , or have a pipe that descends into the thickness of the water horizon.

Self-priming surface pumps

All other pumps considered in this publication will be electrically driven. In fairness, it can be noted that there are and are actively used and pumping units with a power plant based on internal combustion engines, so-called motor pumps, but they do not have, most often, a pronounced domestic use.

So, consideration of the family of surface electric pumps, which is designed to take water out of the well, costs to start with the simplest self-priming systems.

Simple surface self-priming pump

The housing of such pumps never enters into external contact with water and does not require special protection, which greatly simplifies their design. With the source of water, they are connected by hoses or permanently laid pipes, with the obligatory condition being the presence of a check valve - with " air-blasting " they simply can not cope with the task.

There is no cooling system for the drive on them, and this is their vulnerability - if overshot, the probability of overheating is high. The design has no special difficulties, control mechanisms and control - only the inclusion of the and engine shutdown. Thus, for the organization of a system for automatic control over the operation of the water supply system, additional equipment will inevitably be required.

Such pumps are not characterized by high operating parameters. The average level of water created by them does not exceed usually 8 ÷ 10 meters, which is clearly insufficient for the organization of a domestic water supply network. At best, they can be applied to the simplest domestic water supply system - with the storage installed in the upper part of the building, from which water flows to the distribution points without gravity, by gravity .

In a word, it is, although inexpensive, but by far not the best version of nt for i providing residential house with water. The scope of such pumps in private homeownership, rather, the organization of a temporary irrigation system of a site from a well or a natural of a reservoir .

Home pumping stations

This technique is already much more serious than , as it is adapted specifically for the tasks of organizing an autonomous water supply in an apartment building. In addition to self-priming pump, station is necessarily equipped with with gyro-accumulator - membrane tank of , which will constantly maintain the required pressure in the domestic water supply network.

The pump station has an accumulating tank

For this reason, control devices and control mechanisms are included in the overall design of such stations, including the drive when the head falls in the system to replenish the water reserve, and turning off the power supply for to achieve the .

The main problems still remain unresolved - high noise and poor performance of the pumping station part, which does not allow raising water from significant depths - the use is limited to a fence made of Abyssinian or sand wells up to 10 meters deep.

Modern pumping stations can have digital control and noise protection cover

More modern models are also available, with fully electronic control and the possibility of programming some operational parameters. Such pumping stations can be enclosed in a polymeric enclosure that partly solves the problems of increased noise and vibration.

Pumping stations with ejector( injector)

And what if you still need to install a surface pump, but the depth of the water intake is 10 to 25 meters? There is a solution - in this case self-priming pumping stations, equipped with ejector ( external) or an injector( built-in) mechanism will help.

Pumping station with external ejector

In this case, an additional water circuit with a smaller pipe is formed in the water intake system, through which liquid is pumped at high speed. The vacuum created by it in the ejector creates additional pressure in the main intake pipe.

This leads to an increase in pressure - such installations can operate at considerable depths. True, this leads to a general decrease in the productivity of the pump itself, since some of the water is sent back for circulation on the ejector circuit. But the "golden mean", which is arranged and created by the water column, and productivity, can often be selected.

Scheme for connecting a pumping station with an

ejector Another has one big disadvantage - these pumping stations are even noisier than the usual self-priming ones, that is, they will necessarily require the soundproofed premises.

If this option is unacceptable, remains nothing other than , except to choose a pump for a submersible well.

Video: the device and operation of the pump station

Submersible pumps

The main feature of such pumps is stipulated already in their name - they are always located in the water column( in the well or in the well) and connected to the with the water-pipe system of pipes and hoses. The is supplied to the by a long, well-insulated cable. A variety of submersible pumps

The scheme of their installation predetermines also their characteristic constructive features. They always have a reliable waterproof metal case made of corrosion-resistant alloys, with an effective waterproofing of detachable parts and components. It is mandatory to have a gear for securing the safety rope, on which the pump is lowered to the water intake.

The vast majority of pumps are equipped with built-in filters( grids) excluding ingress of machinery and pipes solid suspensions inadmissible for this model size. Many pumps, in addition, have a built-in check valve, which greatly simplifies its installation in the domestic water supply system. If it is not, a special threaded connection is usually provided for the installation of the valve device

. Standard connection scheme for the

submersible pump. There are many advantages with submersible pumps. These include:

• Noiselessness of operation - sound vibrations are extinguished by a layer of water.
• Such mechanisms are not afraid of thermal fluctuations or freezing - in the aquifer layer, the same temperature is almost always maintained.
• At the same time , it is not terrible for them and overheating - the water pumped through them effectively cools the operating units.
• These pumps have much higher capacity and capacity. Some models submersible pumps ( deep) are capable of raising water to a height of 100 meters or more.

The disadvantages are the following:

• Certain difficulties with installing such equipment, often requiring the involvement of specialists.
• The need to build a high-quality secure power line, sometimes for quite considerable distances.
• Difficulties with monitoring the operation of equipment, with the provision of preventive or repair work, requiring each time the pump is withdrawn from the well.

The vast majority of submersible downhole pumps have a characteristic cylindrical shape, representing a metal column in height from half meter to 2, 5 m ., but according to the principle of action they can differ significantly.

Vibratory submersible pumps

Simple reliable , inexpensive, these pumps have gained a very wide popularity among owners of country houses. They can not boast of great productivity, but for household and garden needs is often enough.

Compact and reliable vibrating pump

The principle of operation is as follows. The electric current passing through the windings of the coil causes a periodic, with the defined frequency, an armature pull with which the membrane( diaphragm) and the piston are connected through the stem. The rapid reciprocating motion of this mechanism creates a vacuum in the working cylinder, and water through the valve system is sucked from the well into the pump itself and the is transferred to the through the outlet pipe to the consumption points. The absence of rotating components predetermines the high mechanical reliability of the pump, and the simplicity of the circuitry, completely flooded with a waterproof compound, guarantees the its a long trouble-free and safe operation.

Schematic diagram of vibrating pump device

Some models of vibrating pumps are capable of creating a water column of 20 and even more meters. The pump is easy , it can be completely lowered into the well even on a nylon cord. The power consumption at them is minimal. All is - the expressed advantages of of such devices

Disadvantages of such mechanisms are available, and very significant. Such pumps are quite noisy, but main , that the vibrating waves created by them can eventually lead to the destruction of the wellbore or to the erosion of the clay bottom and walls, a sufficiently rapid siltation of the aquifer. To apply such pumps is recommended only in sand wells, with certain precautions to prevent excessive turbidity of water and sand entering the water intake openings. Ideally, they are more suitable all the same for wells, dressed in concrete rings, and for a well it is more reasonable to choose a pump of a different operating principle.

Video: characteristics of the vibration pump

Centrifugal submersible pumps

The most common downhole pumps are centrifugal pumps. They are a cylinder with an electric drive inside. The rotor axle engine is equipped with a wing turbine, which rotates in the working chamber, which has a peculiar form of "snail", with a supply nozzle in the center and output - on the periphery.

Turbine wheels are of various shapes

The rapid rotation of the turbine causes the action of centrifugal forces that discard the flow of incoming water( the diagram shows the with green arrows) from the center to the walls of the working chamber.

Diagram of water pressure distribution in the

working chamber. As a result, generates an essential pressure difference - from the vacuum in the area of ​​the rotation axis( blue area) to the higher one - to the edges of the blades( in the figure - gradual transition to red).This ensures a constant flow of water from the supply pipe, and the required head at the outlet.

Schematic of a centrifugal pump device with several

chambers A similar circuit is used in most surface pumps, but the required output pressure parameters can be achieved for by increasing the diameter of the working chamber. In downhole pumps, where the dimensions are strictly limited, this issue is different. Achievement of high water column values ​​occurs by sequential installation on one axis of the drive of several cameras.

The water pressure created by one camera is a kind of "support" for the subsequent - and so on. As a result, the output head is made up of the total force of all wheels.

The number of working chambers also determines the overall height of the "column" of the

pump. The number of chambers can vary from two or three and even up to several tens - this predetermines the height of the "column" of the downhole pump and its performance characteristics.

This scheme fully justifies itself - such pumps are capable of raising water from very large depths of . to their advantages also include silent operation, absence of significant vibrations, wide choice in a wide range of generated water column and performance.

The main disadvantages are the complexity of the installation, especially in deep boreholes, the need for frequent maintenance, considerable cost.

Video: modern downhole centrifugal pumps

Screw pumps

Downhole pumps of screw type are not widely used, but nevertheless are on sale.

The working part of them consists of two main parts.

Principal arrangement of screw pumps

The rotor of a complex spiral shape is eccentrically mounted on the electric drive shaft. It rotates in the stator cavity, which also has a complex geometry with one or two spiral turns. The stator housing is usually made of an elastomer - rubber, which ensures a tight fit of the rotary hinges. Thus, in the pump working cylinder there is always a certain number of cavities filled with water. When rotating nt pr pushes these volumes from the inlet to the outlet. The total volume of liquid in the cylinder is never changed, which allows maintaining a steady steady water column pressure.

Such pumps are easy to handle even with liquids of increased viscosity, which predetermines their prevalence in production conditions. However, there are also models for lifting water from wells.

Screw-hole pumps

The scheme of such pumps is effective - they are able to lift water from significant depths, on the order of 40 - 50 meters. However, the presence of knots with increased friction quickly leads to their wear and tear, which requires regular maintenance with the replacement of parts. What is quite acceptable and justified in production conditions will bring a lot of trouble at private using this technique.

Vortex pumps

Another is one circuit that is used in both surface and submersible pumps. The special form of wheel creates not only the centrifugal acceleration of the pumped ox, but also the powerful turbulent its flow, which significantly increases the output head.

The special impeller creates not only centrifugal acceleration but also turbulent liquid flow

Advantages of this circuit are high efficiency, low noise , relative simplicity of the device, which predetermines a lower price compared to centrifugal power of the same type.

Pumps are not afraid of " airspace " - in principle, they can be used even for pumping gas-liquid dispersions.

Representative of the family of vortex well pumps

However, significant drawbacks - low durability and special requirements for the purity of the pumped water, seriously limit the wide use of vortex pumps - they obviously lose centrifugal pumps.

Which criteria should be used when choosing the pump

So, what are the parameters, in addition to the circuit diagram of the pump, it is necessary to evaluate when choosing it:

• Supply voltage and power consumption. If everything is clear with the first value - as a rule, all household well pumps are powered by from 220 V, then the power is a special issue, as it corresponds to the existing power supply possibilities, installed ( automatic, RCD ) and cable parts. Important addition - some pumps ( in particular, centrifugal pumps) do not like voltage drops, therefore , it may be necessary to install an additional stabilizer.
• The maximum head( water column height) - the parameter will be specified in the technical documentation of the product . . This value says not only about the possibility of lifting of water from of a certain depth - water must be pumped through the system of pipes of domestic water supply, its in the accumulator or create the necessary overpressure and have still at least 10% reserve. This issue should be considered in more detail.

There are special methods for calculating the required head of the pump, which scrupulously take into account the diameters and material of the pipes, the number of taps, valves, valves, valves, tees, filter devices along the path from the well to the end points of consumption. It is possible to give sufficiently large tables and complex formulas that are used by specialists.

However, when calculating a pump for a standard private water supply network of a private house, a simplified procedure can be avoided. The result if and will differ from the one received by a professional technique, then with an error that is completely admissible under such conditions.

In calculations, you can focus on the following simplified values.10 meters of water is 1 atmosphere. On pressure losses, 1 meter of vertical section corresponds to approximately 10 meters of the horizontal part of the pipeline for plastic pipes with a diameter of 1 inch, 7 meters for ¾-inch pipes, and 4 meters for ½-inch wiring. With larger diameters, the resistance of the pipes is so insignificant that it can be ignored. All these values ​​already take into account enough the presence of turns, cranes, etc. If the old steel pipes are used in the house wiring, the hydraulic resistance parameters are much higher, and the values ​​should be reduced by one and a half times( 6.7 m - 1 ", 4.7 m - ¾" and 2.7 - ½ ")..

1. So, the first case - if the water supply system of the house is fed from the storage tank.

In this case, the pump needs to be pressurized to overcome the height of the water lift, the horizontal section from the well to the accumulation tank, and create an overpressure at its inlet, which must be no lower than the threshold of its operation to turn off the pump's power supply( usually this value lies in the range 3 ÷ 4, 5 atmosphere).To be faithful, you should add to this another 10% reserve, so that the pump does not work at the limit of its capabilities.

Below is a calculator that will help you quickly calculate the pump head when using a hydraulic accumulator tank:

Calculator for calculating the required pump head for a system with an accumulating tank

2. The second option is the required pressure in the system bIt will be maintained exclusively due to the pressure created by the pump.

With this water supply system, the pump must overcome the height of the rising water to the highest point of consumption, the resistance of the horizontal sections to the farthest point, and at the same time provide the pressure necessary for the correct operation of household appliances( washing or dishwasher, shower cubicle, instantaneous water heater and. P.).

The required values ​​for household appliances are mandatory in the product data sheets. If there is no complicated technology, then for daily use there will be enough pressure in 1,5 ÷ 2 atmosphere( 15 ÷ 20 m of water column).

Otherwise, the calculation method does not differ from the above.

Calculation of the required pump head for direct water supply to points of consumption

• For self-priming surface pumps, the mandatory parameter is the maximum suction depth. That that the pumping plant of this type is capable of issuing a post in 20 - 40 meters, at all still does not say that that it will be able to lift water from such a depth - this parameter is specified separately.
• Pump capacity, that is, the amount of water that it can pump per unit of time. The question can be viewed from two points of view. First of all, the pump must meet the demand for water consumption, based on the existing approximate daily allowance per person. But as during the day the water is consumed unevenly, such a calculation will not be entirely correct.

For example, if you consider their approximate consumption of 200 liters per person, then for a family of 5 people, it would seem that 1000 liters per day is enough. If you take into account that the consumption is about 10 hours a day, it turns out that it seems that there will be enough pump with a modest capacity of 100 liters per hour.

However, such a calculation will be fair to some extent if a pumped storage tank is used. If the water arrives at the consumption points directly, it will be more correct to calculate, based on the actual flow at each of them per unit time, taking into account the probability of a peak load, when all or most of the tapping valves will be used simultaneously.

The approximate flow at various points is given in the table:

The total value of consumption at points, multiplied bythe

k = 1 / √( n-1) , where n is the number of draw-off points

For self-calculation, we recommend using the calculator below:

Calculator for calculating the pump's peak load performance

When choosing a pump for performance,one factor - this parameter should not exceed the real debit of a well. Failure to comply with this requirement threatens to break down the machinery due to "zavozdushivaniya" or absorption of bottom sediments.

• The most important value for a downhole pump is its size. The diameter of the cylinder should be smaller than the casing at 20 ÷ 30 mm. The height of the pump must meet the requirements of its correct location in the aquifer.

The correct location of the submersible pump in the depth of the aquifer of the well

Thus, it is necessary to choose a pump so that it meets both the parameters of the required power and does not exceed the permissible sizes.

• Permissible level of contamination. Usually well pumps are designed exclusively for clean water, therefore the maximum permissible amount of solid suspensions should not exceed 150 mg / liter.
• Additional is equipped with pump. This option includes the presence of systems for protecting the pump against overheating, automatic shutdown for lowering minimum permissible water level, built-in filters and check valves, completing the product with the required couplings, power cable, other spare parts and accessories.

• Well, the last important factor - the price, the spread of which for different models of pumps can be quite large. Nevertheless, , to acquire the best yet high-quality equipment of authoritative brands, which is accompanied by a great warranty period and service capability.

Video: how to approach the selection of pumping equipment