How to choose a pump for a well, well and sewerage?


The choice of a high-quality and reliable pump for a summer residence is one of the urgent and responsible tasks for the owner of a modern country house. A well-chosen pump will allow you to easily organize an autonomous sewer system in the house, bring water from the well to the summer kitchen, and even set up regular automatic watering of your green pets. On the other hand, if the pump is chosen incorrectly, you will hardly be able to implement the full range of planned transformations with it.

The choice of a pump for a summer cottage depends on many factors. It is necessary to take into account not only the fact of the presence or absence of a central water supply, but also such natural features of the territory as the depth of groundwater, the nature of the soil, etc. Decide what tasks you set for the device you are purchasing: are you interested in well pumps for supplying water to the house or do you need a special pump for pumping out a septic tank? In addition, do not discount the number of floors in the house — this is important for choosing a pump!

Types of pumps in the water supply system of a country house

Most often, the purchase and installation of a pump for a country house is not complete without detailed consultations from specialists — do not neglect the opinion of professionals, even if you are confident in your own abilities. However, a basic knowledge of the main types of pumping equipment will allow you to feel more confident in a conversation with the seller and formulate the task as accurately as possible in order to reduce costs.

Pumps for water supply systems of a summer residence or a country house can be divided according to the principle of operation and purpose. First of all, these are surface and submersible pumps — they differ in the very principle of use and installation, which is easy to understand from the name.

Surface pumps draw water from a source and are used for shallow reservoirs and springs. In turn, surface pumps are vortex and centrifugal: the former are used to increase water pressure in the water supply system, and the latter pump liquid well from shallow wells, springs and wells up to 9 m deep.

If the water source is at a great depth and you need a device with more power, submersible pumps should be preferred. As the name of the category implies, such devices operate when completely or partially immersed in water. Most often, the manufacturer completes submersible pumps with float automatic switches, which allow you to fix the critical water level for the operation of the pump in time. Submersible models are also divided according to their purpose: into borehole and well pumps. Borehole pumps will be the best solution for pumping water contaminated with mechanical impurities: sand, limestone particles, etc.

Drainage pumps are used to pump liquid from a pit, drainage wells or a pool. For pumping sewage, special mud or fecal pumps are used. Another specialized type of pumps for a country house — the so-called circulation pumps — is used to transfer coolant in heating systems and hot water supply systems.

What you need to know to choose the right pump

Experts say that most of the damage and malfunctions of submersible and fecal pumps are due to their initial improper installation. Based on the features of its design, the submersible pump is more resistant to wear, however, incorrect installation can cause irreparable damage to the equipment. You should not rely solely on your own knowledge and skill — even if you have extensive experience in using country equipment, it is better to entrust the installation to professionals.

To choose the right pump, professionals recommend paying attention to two basic parameters: water flow and pressure, indicated in the instructions by Q and H, respectively. To find out the desired water flow, calculate the sum of the capacities of all water intake points in the house, taking into account the likelihood of their simultaneous operation. So, for example, it is believed that the toilet in the house consumes 80 liters of water per hour, the sink in the kitchen and the shower — 500 liters each, the faucet for watering the garden and the bathhouse — more than 1000.

To determine the required water pressure, add up the height of the pipeline in the house, calculated in relation to the water level in the well, the total resistance loss inside the water supply system (taking into account filters, friction forces, etc.) and add to this the pressure that needs to be created on water inlet to the building to provide a pressure of 0.5 atmospheres at the highest water intake point of the house.

In addition to these indicators, when installing a submersible pump yourself, you will need to take into account the well parameters indicated in the passport. First of all, this is the flow rate of the well, as well as its static and dynamic level. It is impossible to determine these data by eye — they are specially measured by employees of the organization that was responsible for drilling.

Why the wrong choice of pump is dangerous

Sometimes consumers, when choosing equipment, prefer high quantitative indicators, not paying attention to the requirements of the water supply system as a whole. So, for example, often, guided by the “more is better” attitude, the customer installs a pump with oversized power in the hope of getting a better quality of the device. However, in reality the result will be the opposite.

If the nominal capacity of the pump exceeds the actual need of the inhabitants of the house to use clean water, the device will operate in the mode of regular switching on and off. Manufacturers allow up to thirty pump starts within one hour, with a total number of starts per day not exceeding sixty. Frequent starts of the pump quickly wear out the engine and starting automation. To avoid breakdowns, you will have to install a membrane tank with a large volume.

In addition, a pump that is too powerful will also increase the water pressure at the inlet, which will lead to inevitable high-pressure hydraulic shocks at start-up. Such shocks can seriously damage the fittings of household appliances and some parts of the water supply system. Those. by choosing the wrong pump, you seriously risk not only the forced installation of additional gearboxes, but also the life cycle of your washing machine or faucet.

If there is a pool on the site, then a pump that is too powerful increases the flow of water at a minimum pressure in the system. Such work will quickly disable the electric motor due to the creation of maximum power on the shaft.

As you can see, a frivolous approach to choosing a pump always increases the cost of maintaining a water supply system at times, while not increasing its productivity. So, for example, if the nominal flow of the selected pump turns out to be greater than the well flow rate indicated in the passport, it will be necessary to additionally install “dry-running” protection in the system, however, setting and throttling the pump will increase electricity consumption.

Most often, the customer’s decision to install a more powerful pump on the site is associated with the desire to ensure the possibility of simultaneous use of all water intake points in the house and on the territory. In fact, the above calculation method should show you the maximum indicators — the actual water consumption will be less in any case. It is unlikely that you will take both showers at the same time, fill the pool, use the bathhouse and wash dishes in the kitchen. Increasing the power of the pump will not increase the family’s water consumption, but it will seriously affect the overall cost of the water supply system. So, for example, if you calculated that the total water consumption in a house with a swimming pool, a bathhouse, several bathrooms and an irrigation system will be 6.5 m³ / h, then you can safely assume that the required water consumption is 5 m³ / h — take the maximum figure would simply be inappropriate.

Proper installation of the pump is a guarantee of reliable operation

After the final selection of the pump, you need to carefully calibrate its duty point in each mode of operation. Measure the supplied water flow when commissioning the appliance — it is easily determined by the filling rate of a container of which you know exactly the volume (for example, a garden barrel). According to the pressure gauge on the head, specify the pressure created by the pump, use current tongs to measure the electricity consumed in this case.

Now compare the results with the characteristics of the selected pump from the catalog. If the operating parameters are exceeded, the outlet valve should be closed, creating additional local resistance in the system, which will be sufficient to establish the correct operating point of the pump. When comparing, keep in mind that the manufacturer leaves some power reserve in the passport (for example, taking into account the subsequent possibility of installing filters in the system).

Remember that only trained professionals with a license to work with this equipment should install the pump in the water supply system.


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