How to choose a pump for a well on your own dacha

After drilling a well and installing all related equipment, it is the turn of installation and connection of the most important element of the water supply, namely the well pump. However, before you buy it, you need to study the basic characteristics of the well in order to select the necessary parameters of the pump unit with maximum accuracy.

This can be said, the most crucial stage in the construction of the well. After all, the performance and durability of the water supply system, the safety of its use, as well as the qualitative composition of drinking water largely depends on how well the pump will be selected for the well and its installation.

Well pump

This article will offer instructions describing the basic parameters of downhole pumps, which will help make the right decision in favor of a particular unit.

In addition, the reader will be presented with the main selection criteria, which should be paid attention to when buying it, as well as a brief guide on how to choose the right pump for a well that has certain technical characteristics.

Surface pumps

For pumping water from underground wells, there are two types of pumping units: surface and submersible. As the name implies, surface pumps are installed on the ground in close proximity to the wellhead.

They are cheaper, easier to install and maintain, however they have some features of work that significantly limit their convenience and scope:

• For their installation requires a special room.
• High noise level during operation.
• The need for forced engine cooling.
• Before start-up, priming is required.
• The maximum distance from the height of the working body to the dynamic water level in the well can be no more than 7-8 meters.

Such pumps should be used for seasonal use in underground sources without a caisson with a high dynamic level of liquid, as well as for the extraction of process water in the upper layers of groundwater.

Submersible pumps

Submersible-type devices that are installed in the wellbore below the dynamic level of the liquid directly in the water column are most widely used for pumping water from the well. They are considered the most versatile and have good performance.

The advantages of submersible pumps include the following characteristics:

• High reliability and durability.
• Ability to work in any climatic conditions, regardless of the season.
• High performance and height of the liquid head.
• Before starting, no priming of the working fluid is required.
• In the process, no forced cooling is required.
• Fast start-up, low inertia and silent operation make them an ideal option for working in tandem with an automated water supply system of a private house or home farm.

Of the shortcomings of submersible pumps, the most noticeable is their relatively high price and the more complex process of installation, maintenance and repair.

Taking into account all the pros and cons of units of this type, their use is a priority for the extraction of water from underground sources, so in the future we will talk specifically about pumps of the submersible type.

Water flow

One of the most important indicators of any pump is water consumption or, in other words, its performance. This value is characterized by the volume of the pumped liquid per unit of time, for example, 6 cubic meters per hour or 0.5 cubic meters per minute.

To know how to choose a well pump on this basis, it is necessary to find out the flow rate. Under the debit is understood its ability to produce water for pumping at a certain speed without a significant reduction in the dynamic level.

Typically, the flow rate is indicated in the technical passport of the well, which is given by the drilling company, however, the exact flow rate for each particular well is very difficult to determine, since this value is not constant and may vary over time depending on various conditions.

It should only be said that the recommended pump capacity should be 10-20% less than the well flow rate. This will allow the most efficient use of the aquifer and at the same time avoid the drainage of the well and pump operation in the dry run mode.

   Tip! The most optimal well flow rate is achieved when the following conditions are met: during water pumping for one hour, the difference between static and dynamic levels should be no more than 1 meter.

Head height

Another important parameter that affects the selection of a downhole pump is the maximum relative height by which it is able to lift the working fluid. The required head height mainly depends on the depth of the well and the level of location above the ground of the highest water consumption point in the building.

In order to accurately calculate the required head height, you need to add the depth of the pump to ground level and the maximum height of the water users. In addition, to ensure normal working pressure in the water supply system, it is necessary to add another 30 meters to the obtained value, which corresponds to a pressure of 3 Bar.

   Note! As an example, consider a well 40 meters deep, located next to a two-story house with a height of 6 meters. To determine the height of the pressure, you need to add the length of the pressure pipe (40 m) with the height of the second floor of the house (6 m) and add the height necessary to achieve the working pressure of the system (30 m). Thus, the optimal height of the pump head will be ~ 80 m.

Casing diameter

To select the right pump size, you need to know the inside diameter of the casing pipe. The bulk of the submersible units are available in two sizes depending on their external diameter of 3 inches or 4 inches. In millimeters, these are ~ 75 and ~ 100 mm, respectively.

When drilling a well, it should be borne in mind that a wider product range is available in a 4 inch size range, so it is better to use casing pipes with an internal diameter of at least 110 mm.

Submersible units with a diameter of 3 inches, in addition to the fact that they are less common and in a smaller range, also have a higher cost compared to 4 inches. Therefore, when installing a submersible pump in the well with their own hands, it is recommended to give preference to models with a 4-inch case diameter.

   Note! When choosing a unit for domestic water supply of a residential house, taking into account the average daily water consumption for a family of 4 people, its capacity should be 3-4 m? / Hour.

Conclusion

After reading this article, it is easy to understand that for self-selection of pumping equipment, it is enough to know the main technical parameters of the well and have a water supply scheme for your home.

For more information, you can watch the video in this article or read similar materials on our site.