How to choose a pump for a well when there is no special knowledge? The task is not easy. First you need to tell what they are in general. All devices can be divided into several types.
Surface devices work on the mirror surface of water. These include summer cottage and garden pumps, circular, pressure and pump stations. Submersible devices during operation are lowered into the water. And in order to choose a submersible pump for a well, this class will have to be studied. Such devices are used in wells, boreholes, to remove feces and drainage.
Submersible pumps
Such a device works with full or partial immersion in a liquid. This requires reliable insulation of electronic automation and bare wiring. When assembling such a pump, durable waterproof polymers and stainless steel are used.
This type of equipment is designed to produce water from artesian wells, therefore it has a high pressure.
Due to the conditions of use of the devices, certain restrictions are imposed on them, in particular, on the case material and its diameter.
As a rule, a submersible unit is a cylinder made of stainless steel with a diameter of less than one hundred millimeters. The length can range from five hundred millimeters to two and a half meters.
Due to the severe restriction of the footprint, the designers had to rack their brains to achieve good performance and create high pressure. That's why choosing a submersible pump for a well is not easy. A multi-stage suction system is one of such complex technical solutions. Such delights, in addition to the advantages in work, give a significant minus - an increase in cost.
Well pumps
Since a conventional household appliance installed on the ground cannot supply liquid from a great depth (the maximum limit from which it can lift water does not exceed ten meters), well devices are called to cope with this task. How to choose a pump for a well? You need to know its principle of action. It is based on the fact that it is much easier to create enough pressure from below to raise water upwards than to try to raise it from above by pumping air.
Well pumps
The well is arranged in the same way as the well pump. How to choose a device for a well? You need to know that they are adapted to work both in wells and in natural reservoirs or special tanks. Their shape is also cylindrical, but the diameter is larger.
This allows them to use an installed engine with greater efficiency. Such pumps have higher performance and lower cost at the same power and pressure as those considered above. The strong draft of these devices creates a "suction cone", so they should not be brought closer to the bottom of the reservoir closer than a meter. The pump will not suffer from such a violation, but the quality of the supplied water will significantly decrease.
In the kit, the well devices have an adjustable float switch that provides autonomous operation of the device.
Drainage pumps
The purpose of this type of device is to pump water from flooded basements, ponds, pools or other places that need to be drained quickly. It happens that they are used for pumping drinking water, but this is not their task.
Devices of this class have good performance, but low pressure and therefore can not supply fluid from a depth of more than seven meters. They are installed directly on the floor in a flooded room or on the bottom of a small reservoir with water.
Fecal pumps
The scope of these devices is clear from the name. The design of the device allows you to work with viscous soft substances. The inlets are specially enlarged for the same purpose.
Surface pumps
In this group are units that are installed remotely from the liquid that they have to pump. However, some can be installed on a special float (made of polystyrene, for example), if the dimensions and weight allow, and are lowered into the water. Such a need arises when a large amount of algae accumulates near the shore, or the bottom is covered with silt near a reservoir.
The depth with which they are able to lift water is less than ten meters, and for pumping from great depths it is necessary to use all kinds of tricks. One of them is the use of an external ejector. This is a special device that, together with the suction hose, is lowered into the water. When the pump is running, the liquid rises up, where part of it flows through the additional hose back into the ejector, which increases the inlet pressure. It turns out that the water below is "pushed."
As the depth of the system increases, performance decreases, and design complexity and power grow in inverse proportion. At a depth of twenty-five meters, the price of a surface pump is equal to the cost of a well pump.
Garden pumps
These devices are versatile and structurally simple. Used for various household needs, in particular, for pumping drinking water. To ensure uninterrupted water supply, garden pumps are additionally equipped with monitoring automation, a hydraulic accumulator. The cost of these devices is low.
Pressure pumps
These units are equipped with the necessary automation immediately and are able to provide an uninterrupted supply of water without an additional accumulator.
The devices of this particular group will help answer the question of how to choose a pump for a well or a well.
Built-in automation helps not only with the organization of the water supply, but also with the irrigation of the garden.
So, when the hose is bent, when the watercourse stops, the pump automatically shuts off, which will prevent engine overload. The device will “wait” until the interference is eliminated, and only then resume the water supply.
Pumping stations
These are full-fledged uninterrupted water supply systems, which include a pump, a hydraulic accumulator, and a pressure switch. Intended only for stationary installation.
If a little water is consumed, then it is supplied from the reserve, and the engine does not turn on, which allows to increase its service life.
According to the principle of action, all pumps are divided into vibration and centrifugal.
Centrifugal pumps
Most household appliances are included in this group. The main part of the working mechanism is a shaft with a wheel fixed on it, placed in the housing. Wheel - two discs that are connected by the blades located between them. And each of the blades is curved in the opposite direction of rotation. There may be several of these wheels.
During the operation of the pump between the blades, the cavities are filled with the pumped liquid. When the wheel rotates, centrifugal force acts on the water. It creates a zone of high pressure on the periphery, and in the center - low. Due to the pressure difference, water from the outside goes to the center where the vacuum has formed, and thanks to a kind of hurricane it goes out directly through the outlet pipe.
Vibrating pumps
For these devices, the main "working body" is a flexible membrane. On one side of it is a cavity that is filled with pumped water, and on the other, a vibrator that causes the membrane to deform with a certain frequency. The working volume changes either smaller or larger, which depends on the direction of the bending of the latter. And this, in turn, increases or decreases pressure.
Initially, a vacuum occurs, the intake valve opens. There is a suction of water.The vibrator then creates excess pressure, pushing the fluid out through the exhaust valve. According to this principle, the pump "Stream".
How to choose a pump for a well
Two main parameters influence the choice: head (to what height can the water deliver), capacity (how many cubic meters or liters of fluid can be pumped per hour). How to choose a pump for a 30 meter well? For a person to feel comfortable, he needs a thousand liters of water per day (even with a double bath per day). The required amount per family is easy to calculate: you just need to multiply the number of people by a thousand liters. So, for a family of three, three thousand liters is enough for a day.
Another indicator is maximum consumption. How to choose a pump for a well based on this factor? The maximum flow rate is determined by the ability to use water simultaneously from several points. For example, when three family members decided to use a shower (consumption of 8-10 liters per minute), a toilet (consumption of 6 liters per minute) and a faucet in the kitchen (6 liters per minute) at the same time. In this case, the maximum flow rate will be 22 liters per minute. A family of four to five people will need four to five thousand liters per day at a maximum flow rate of about thirty liters per minute.
And if it is planned to water the area for which the pump for the well will be used, how to choose it in this case? Here the determining factors will be the size of the garden and the weather. Under normal conditions, two thousand liters per day will be more than enough. How to choose a pump for a 20 meter well? To determine the minimum pressure that is required, you need to take the height of the house and add six meters. The resulting number should be multiplied by 1.15. This is the coefficient of pressure loss during the passage of water through the pipes.
So, if the house is ten meters high, then the minimum pressure of the borehole pump should be 18.4 m ((10 + 6) x 1.15). If water comes from a well, then an apparatus with a pressure of 18.4 m will be required, providing a flow rate of 1800 liters per hour. If the water source is a well, then its depth will have to be added to this pressure value, more precisely, the distance from the water mirror to the surface of the earth. This must be taken into account when deciding how to choose a pump for a 40 meter well.
If this distance is thirty meters, then a pressure of 48.4 m (30 + 18.4) will be required for the water supply system described above. The flow rate at a similar pressure will be equal to 1800 liters per hour. It is also necessary to carry out calculations when deciding how to choose a pump for a 20 meter well. When the water source is located at some distance from the house, you need to know that for every ten meters of the length of the pipe running horizontally, there will be 1 meter of pressure loss. How to choose a pump for a 10 meter well? It is very important to determine the correct pressure characteristic. It is enough to equalize the flow rate to 800-1000 liters per hour. The simultaneous use of all water consumption points is unlikely, and in this case, the maximum flow rate can be achieved with the help of a hydraulic accumulator.
How to choose a pump for a well? And the connection diagram
Well pump manufacturers
From the category of "economy":
- "Aquarius" (Ukraine), "Water-jet" (Russia).
- Cheap but unreliable - Ebara, Espa, Hydro-Vacuum (Poland), Omni Gena (China), Omhi Aqua, Sprut Cristal Hydrofren Kenle, Aquario (like Italy), Pedrollo.
- Not as simple as the previous ones, but without protection options - Wilo (Germany), KSB, OFT (Italy), DAB, Calpeda, Saer.
To buy a pump for a well of this class means to ensure water supply with a minimum investment. An additional installation of the control unit will protect the device from dry running and overloads, but this will increase the price of the water supply system and bring it closer to the cost of the Grundfos SQ, in which these functions are already built-in and still have a smooth start.
Such a water supply system for a country house will provide water needs for living seasonal or permanent, with moderate use of water.
But all of the above devices are suitable for wells with a pipe diameter of at least one hundred and ten millimeters. This should be considered when ordering a water supply system. How to choose a pump for a Grundfos well? To do this, consider the following two classes.
From the category of "business": Grundfos SQ Series.
This model range has built-in protection that protects the device from “dry” running, as well as a soft start system, which will ensure uninterrupted operation of the unit for a rather long time period.
The system has a supply of water, which provides a membrane tank with a volume of one hundred liters or more.
The devices of this series are used in organizing water supply from a well of any design with a pipe diameter of at least eighty millimeters.
From the category of "premium": Lowara (Italy), Grundfos SP (Denmark-Germany), Grundfos SQE processor controlled.
The use of devices of these series will allow to maintain constant pressure in the pipes in the absence of pulsation, to ensure the same fluid flow at any point in the intake. If there is a water heater, then the output will be a stable temperature. An effective monitoring and control system for such an aggregate will ensure its long life.
To buy a pump for a well of this class means to provide the most comfortable water supply for cottages and private houses thanks to full automation.
The main causes of breakdowns
"Dry running." This is work during the absence of water, which causes the engine to overheat, since the pumped liquid usually performs the role of a cooler. Due to the same reason, seals also fail, for which the pumped liquid acts as a lubricant.
Water hammer. This occurs when the “dry” apparatus is turned on, when the water pumped inward hits the impeller blades with force, which can damage them. The same effect will result when there is an air bubble in the intake hose.
Freezing fluid. This can damage the unit quite seriously. And if the pump is located in a place where it is possible to lower the temperature below zero Celsius (unheated room in winter), then the water from it must be drained.
Overheat. Occurs when the temperature of the pumped water rises above the maximum allowable limit. This is not as destructive as the “dry run”, but the signs are the same: due to the high temperature of the liquid, heat transfer is slower, which leads to overheating of the engine.
