Submersible drainage pumps minimum level. How to choose a drainage pump. Pump selection depending on the pumped medium

Drainage pumps are quite widely used in agriculture, manufacturing and construction. They are indispensable helpers in everyday life and for the category of people who thought badly when choosing a site for the construction of a house or cottage. With their help, it is possible to effectively pump out water when the lower rooms are flooded - this to some extent will increase the service life of the structures.

The main area of ​​application of drainage pumps is the pumping of heavily polluted water, sometimes containing large particles of dirt, from various containers: trenches, pits, basements, cellars, pools.

Rice. 1 Drain pump design

Structurally, the drainer is made in a plastic or metal case, which houses its main components. An impeller with a spiral impeller is fixed on the motor shaft, the electric motor itself is placed in a separate metal case. At the bottom of the housing there is a grate through which the liquid is sucked in. The perforated holes in it are designed for the maximum allowable particle diameter with which the device can work.

All models of submersible drains are equipped with a float switch that opens the power supply circuit of the electric motor, if the water level is low, the device drops and the ball inside its structure falls down onto the lever, which opens the contacts.

The float switch performs not only the functions of protecting the engine, but also organizes an automatic mode of operation, monitoring the water level and turning off drainage pump when the minimum value is reached and switched on again when filling.

When power is supplied to the pump motor, its impeller sets in motion and begins to suck water through a small hole in the device body in the center of its axis. Under the action of centrifugal force, the incoming water is pushed out through the outlet pipe located on the side of the drainage pump housing.

Main characteristics of drainage pumps

Power consumption. The main parameter of the device, responsible for its performance and efficiency.

The size of the filtered particles. Submersible drainage pumps for water are designed to work in different environments, so the specification usually indicates the particle size in the working environment in millimeters, which does not cause clogging of the filter and the installation of work.

Maximum pressure. The pressure is understood as the pressure (specific energy) created by the pump for pumping water, for ease of understanding, it is given in meters.

Maximum water temperature. The operation of the drainer in a high temperature environment contributes to overheating of its engine, which is unacceptable, since the engine cases are designed for water cooling in the working environment.

Immersion depth. The maximum distance that the drainage pump can be put into the water intake source for its uninterrupted operation.

Performance. The capacity of the pump, indicating the amount of liquid raised per unit of time (measured in cubic meters or liters per hour).

Types of drainage pumps

Like all other similar devices, drainage, depending on the installation site, are divided into two types: surface and submersible.

Surface drainage pumps

They are placed on the surface of the earth near the place of water intake, a suction pipe is installed on the bottom of the tank with the pumped liquid. The float mechanism necessary for the operation of the drainer is fixed at a small height from the bottom and automatically turns the device on and off when the liquid level in the tank changes.

Surface devices are easy to maintain, have good mobility and the main disadvantage: a small suction depth.

Submersible drainage pumps

The body of the device is placed directly in the tank with the liquid being pumped out, usually it is installed on the bottom, using a small stand to prevent sludge from being sucked in. Water enters the housing through the filter in its bottom, the float sets the operating mode.

Compared with surface types, the submersible drainage pump has the best performance: capable of pumping water from great depths, its performance and power are greater.

Drain pump models

For comparison, we present the characteristics of the most common models of submersible type drains (external ones are practically not used in everyday life).

Prorab 8720 PP is a good option for those who do not know which drainage pump to choose - the model has an excellent price-quality ratio.

Peculiarities

• installation depth: 5 m;
• head: maximum 8 m;
• pumping volume: 13 cu. m/hour;
• power: 750 W.;
• particle filter: 35 mm;
• control: float.

Gileks Kachok 550/14 is a fairly powerful submersible type drainage pump with a vertical installation from a domestic manufacturer for pumping large volumes of water.

Rice. 5 Gileks Kachok 550/14

Peculiarities

• installation depth: 8 m;
• head: maximum 14 m;
• pumping volume: 33 cu. m/hour;
• power consumption: 2000 W;
• particle filter: 40 mm.;
• operating temperature: up to 35 C;
• cord: length 10 m;
• control: float.

When choosing a drainage pump for pumping water, you should take into account the parameters of the object for work. External views are more practical to use with small volumes of pumped liquid from shallow depths - in this case, they have small overall dimensions, they are easier to install and move. For large volumes of pumping and long-term operation, submersible type domestic drainage pumps are better suited.

Drainage pumps

In the "Pumps" section, we will consider another type of pumps used in bits and industry - these are submersible drainage pumps. Drainage submersible pumps are used for pumping clean or slightly polluted water from cellars, pits, reservoirs and wells, for automatic emptying of pits and shafts, for keeping flooded buildings and basements dry, for lowering the water level, if polluted water cannot be discharged under natural slope into the sewer. The pumps are also used for pumping slightly polluted, rain and wash water. Drainage pumps are not used for pumping water containing coarse impurities such as sand, fibers or faeces, nor are they used in explosive environments. These pumps can be mounted both stationary and in a mobile, portable version.

Technical characteristics and arrangement of drainage pumps

Operating characteristics

• The temperature of the pumped medium is not more than 35°С
• Submersion depth of the pump is not more than 5 m
• Maximum solids diameter Ø 5 – Ø 35 mm depending on the model
• Minimum liquid level, 15 - 70 mm depending on the model

Engine

• With built-in thermal overload protection
• With built-in capacitor
• Insulation class F
• Protection class IP 68

materials

• Pump handle plastic or stainless steel depending on the model
• Pump housing plastic, cast iron or stainless steel depending on the model
• Impeller Noryl polymer or stainless steel depending on the model
• Motor housing plastic, cast iron or stainless steel depending on the model
• Rotor shaft stainless steel
• Double mechanical seal with oil chamber

The housing of the drainage submersible pump, depending on the model, can be made of plastic, cast iron or stainless steel. The electric motor is hermetically sealed from the ingress of the pumped medium into it. Depending on the model, the drain pump motor may be oil-filled. The pump shaft has a mechanical seal to isolate the oil chamber from water. The engine is cooled by the pumped medium in which the pump is located.

Installation and connection of pumps

The pump is mounted at the bottom of a pit, pit, tank or cesspool. The pumped medium enters the sewer through a hose or permanently through an installed pipe. As a rule, the drainage pump operates in automatic mode, since it is equipped with a switch that turns on the pump at a certain water level “h” (Fig. 1) and turns it off at a minimum water level “h1”.

Drainage pumps should not operate without liquid, this mode of operation leads to overheating and destruction of the mechanical seal between the pump and the motor. It is necessary to adjust the float shutdown of the pump in such a way as to maintain the minimum water level “h1”, depending on the model and brand of equipment. The passport indicates the minimum water level. When installing submersible drainage pumps, pay attention to the following:

• The installation site of the drain pump (pos. 1) as well as the tank or well itself must be protected from frost.
• When installing the pump permanently, the bottom of the shaft or pit must be flat and free of large objects and dirt, such as construction debris, bricks and earth.
• The diameter of the pressure line (pos. 2) or hose must not be smaller than the diameter of the pump's discharge port. To avoid pressure loss, it is recommended to select a pipeline or hose with a larger diameter than the pump discharge port.
• In order to protect against a possible reverse flow of the pumped medium from the sewer pipe, it is necessary to install a valve (item 4) and a valve (item 5) on the pressure pipe for protection during stationary installation.
• When installing the pump in a portable version, lay the pressure pipe or hose in the form of a loop above the maximum sewage level for the area (usually this is ground level).
• The threaded connections of the pipeline must be sealed with tow or fum tape.
• When installing the drain pump, care must be taken to prevent it from being disconnected from the discharge pipe and to install it to prevent suction of silt or sand.
• The pump must be installed in such a way that it can be completely submerged in the pumped medium. Adjustment of the level of turning on and off the pump can be changed by changing the length of the float switch cord (Fig. 1).

It is strictly forbidden to carry, raise or lower, and even more so to hang the pump by the power cable or float attached to the pump. A rope or chain must be used to lower or raise and to secure the drain pump.

To ensure free movement of the float switch, the minimum dimensions of the well or pit for the drainage pump should be length - width - height 40x40x50 cm. Alternatively, concrete well rings with an internal diameter of 40 cm can be used.

Electrical connection drainage pumps

The electrical connection of the drain pumps must be carried out by a qualified electrician in accordance with the Electrical Code (EEC) and in accordance with local requirements, codes and standards. While doing electrical connections you need to pay attention to the following:

• The mains voltage must match the voltage indicated on the nameplate of the pump.
• The drain pump must be connected to the power supply using a socket with a ground wire powered through the equipment (RCD) with a rated leakage current of 30 mA. The socket must be mounted in a dry room and in a place inaccessible to water.
• The single-phase asynchronous AC motor has a built-in thermal protection that turns off the pump when the motor is overloaded and automatically turns it on after it cools down.

The electrical connection diagram of the drain pump is shown in fig. 2.

Commissioning of drainage submersible pumps

The float switch must be free to move. The switch must turn off the pump before the suction screen of the pump draws in air. After filling the well / pit and opening a tap or valve on the discharge pipe, the pump automatically turns on when the switch-on level “h” is reached, and turns off when the switch-off level “h1” is reached (Fig. 1). The submersible drainage pump must not run dry (without water). Adjustment of the level of switching on and off of the float switch The level of off / on of the drainage pump can be adjusted by changing the length of the arm of the float switch, fixing it with a special bracket on the pump handle using a cable. Waste water entering the well or pit must not fall on the intake screen of the pump. The air present in the incoming water can enter the working chamber of the pump and air it. The maximum volume of sewage entering the well / pit should not exceed the pump capacity. During the first start-up, it is necessary to make sure that the drainage pump has time to pump out the incoming volume of water.

Operation, maintenance and repair of drainage submersible pumps

Usually, submersible drainage pumps during operation, does not require special maintenance. In order to avoid jamming of the pump impeller due to long periods of inactivity, it is necessary to regularly (every 2 - 3 months) check the operation of the pump and the float switch. To do this, turn on the pump for a short time by forcibly raising the float switch. During operation, every 3 months it is necessary to clean the walls and bottom of the well or pit from dirt and sand. It is also necessary to flush the pump housing and the intake grate, and if necessary, remove and clean the grate, and then reinstall it in its original position.

During the operation of the drainage pumps, measures must be taken to ensure that the immersion depth of the pump does not exceed the mark indicated on the pump housing. If this value is exceeded, there is an increase in the load on the gland seal. It is also necessary to monitor the presence of sand in the pumped water. Due to the increased content of sand or suspension in the water, the shaft seals and seals wear out. Damage to the mechanical seal causes oil from the oil chamber to enter the water. And the chamber itself is filled with water. Then the process is even more aggravated, water begins to enter the drain pump motor. If there is a protective shutdown device for the equipment, the pump will be disconnected from the mains. If the RCD is not installed, the engine will safely “burn out”. The cost of repairs will increase dramatically, since in addition to simply replacing the stuffing box rings and oil, rewinding the motor stator will also be added. Repair and maintenance of this equipment should be carried out only in specialized service centers.

Water can enter the motor through cable glands or damaged cable insulation. This usually occurs when a mechanical load is applied to the power cable. Therefore, when installing the equipment, the cable must be attached with cable clamps to the pressure pipeline with sagging. Therefore, once again, it is strictly forbidden to lower or raise the drainage pumps using the power cable.

If the drain pump is used as a portable one, then after each use it is necessary to wash the pump and the float with a jet clean water. Store the equipment in a dry and ventilated area.

Thank you for your attention.

Drainage pumps are used when you need to quickly pump out a large amount of dirty liquid. Doing it manually is a bad decision, because it will take you too long to work. And the result won't impress either. It is better to choose a good drainer that will cope with the same tasks, but much faster.

This article will discuss the types of drainage pumps, their differences and features, as well as provide recommendations on how to choose a drainage pump for domestic use.

1 Types and their differences

Depending on the design features, all drainage pumps are divided into two categories: submersible and surface.

The submersible drain only works when completely submerged in water, as it requires constant external cooling. power unit. Such devices have a lower water intake system, which makes their use very convenient for cleaning a well with your own hands, or for pumping out deep sources.

As a rule, submersible devices have the best specifications in terms of power and pressure than surface drains, since the submersible unit operates at great depths and needs to have a powerful drive to push water out.

The main advantages of submersible pumps include compact size and light weight, which allows you to easily install it on the bottom of the source (for example, Whirlwind 1100N weighs only 7 kg, and this is a pump from the initial price category, whose technical characteristics are far from ideal).

Also, noiselessness can be attributed to the advantages of such devices, since the sound of the drive is muffled by a layer of water, under which there is a submersible pump.

Submersible-type drains are more durable than surface devices, however, their repair is carried out much more often, since the device is constantly exposed to the aggressive effects of water and the pollution present in it, while repairing them with your own hands is quite difficult, since due to disassembly of the case, its tightness is violated.

In general, the purchase of a submersible drainage pump for a summer residence is justified only if there are clear goals for its use, since such a device has much less versatility than a surface drainage pump. Attention should be paid to Karcher SDP 5000 and Karcher SDP 18000LS.

Depending on the functional purpose, fecal pumps can be distinguished from the group of submersible drainage units, which are used for do-it-yourself pumping of septic tanks, cesspools, and drains with a large amount of mechanical pollution. The highest quality fecal pumps are manufactured by Pedrollo, Grundfos and Karcher.

Surface drains are much more convenient to use, due to the fact that they do not need to be constantly lowered and removed from the source with their own hands. However, they do not provide the necessary efficiency for pumping water from deep sources.

The maximum immersion depth for the most popular pumps on the market from the middle price category is as follows: Caliber NPTs 400D - 8 meters, Whirlwind 1100N - 10 meters.

In principle, this depth is more than enough for giving, and any domestic use. If the capacity of the surface drainage is not enough, then you need to pay attention to centrifugal pump designed for pumping dirty water.

The advantages of submersible devices also include a long service life, due to less wear of the working part than that of submersible pumps, and simple do-it-yourself repairs. However, in order to carry out repairs, you will have to understand its design, which is not so easy.

The disadvantages are the noise during the operation of the power unit, however, in open spaces typical for summer cottages, it is almost invisible. Also, as already mentioned, their power is somewhat less than that of submersible counterparts.

2 How to choose a drainer for performance and pressure?

The key technical characteristics that should be considered when choosing a drain are its power (capacity) and pressure.

The approximate performance of the pump is determined based on the volume of water that it will pump out. So, if you need to drain a tank with a volume of 13 cubic meters, then a pump with a capacity of 4.2 m3 / h (take for example the PN-1100N Whirlwind) will do this in three hours. For summer cottages, pumps with a capacity of 5-10 m3 / h are the best option.

The characteristics of the pressure of the device should depend on how far the water needs to be transported, or from a source of what depth it needs to be raised.

In practice, ten meters of horizontal water supply is equal to one meter of its rise, which means the following: if a centrifugal pump has a head of 50 m (the same Vortex PN-1100N), then it will be able to raise water from a source 50 m deep, or pump it 500 m horizontally.

Consider how to choose a drainage pump for additional parameters. It is recommended to give preference to products whose body is made of stainless steel or cast iron. They, of course, will cost more than plastic counterparts, but the quality of the case directly affects the life of the unit.

This is especially true for submersible drains, which are constantly under the aggressive influence of the working environment.

Keep in mind that in case of deformation or malfunction of the metal case, you can repair it yourself by soldering or welding the damage, but if the plastic case breaks, the only thing left is to use the pump as a donor of spare parts for the new device.

Another important factor is the material of the impeller blades of the pump. They can be made of stainless steel or special technical polymers. It's the opposite here: stainless steel wheels in practice have a high wear rate, and therefore pumps equipped with them are cheaper.

Technopolymer impellers are made with special additives that make them resistant to mechanical damage and corrosion. The only minus of plastic, again, is repair. Repairing such materials will certainly put you in a difficult position, which must be taken into account without fail.

Be sure to choose those drains that are equipped with a float switch. "Float" performs automatic shutdown pump when the water level has dropped below a predetermined level, which protects the drain from running dry, and turns on the device when the water is restored.

Automation does not require turning the pump on and off with your own hands, which allows it to function normally during your absence.

It is also important to choose a pump according to the contamination of the water for which it will be used. The technical documentation for each drainer indicates what size impurities it can work with:

• From 25 mm to 38 mm - these pumps are perfect for pumping heavily polluted water - rain, melt and for cleaning wells and wells;
• From 25 to 5 mm - for medium-polluted water, usually such devices are used for watering vegetable gardens with technical water - best option for giving;
• Up to 5 mm - for drainage of clean water, for example for pumping pools.

2.1 Who manufactures the drainage pumps?

Market analysis shows that the most popular devices for domestic use are pumps of domestic production "Caliber". These devices have an optimal price-quality ratio, which makes the Caliber drains great option universal pump for a summer residence, or a private house.

The device of the drainage pump "Caliber" includes a centrifugal drive, which guarantees it high performance - a 400 W unit ("Caliber NPTs400D") has a pressure of 8 meters and produces 6.9 cubic meters of water per hour.

The advantages of Caliber pumps include endurance, which distinguishes them from competitors. Drainage "Caliber" without problems cope with water, which contains a large amount of mechanical impurities, which allows them to be used not only for pumping water, but also for cleaning wells and shallow wells.

An important factor in the popularity of Caliber pumps is also the simplicity of the design, which allows them to be repaired by themselves.

With the mass distribution of air conditioners, the market for compact pumps, which are used to pump out accumulated condensate, has greatly developed. We decided to compare the leaders in this market segment to find out which compact drainage pump is the best today.

For comparison, Sauermann Si 2750 devices and a Mini Orange pump from Aspen were selected. They have the best technical characteristics in their price range:

1. Cost: Sauermann Si 2750 wins in price, they ask for about three and a half thousand, while Mini Orange will cost you 5 thousand rubles.
2. Power: Mini Orange leads in performance, this pump at maximum load is capable of delivering about 14 l / h, while the Sauermann 2750 is only 10 liters. In other matters, for household air conditioners, whose power rarely exceeds 20 kW, both devices are perfect.
3. Head: suction lift for Mini Orange - 8 meters, for Sauermann 2750 - 2.5 m.
4. Noisiness: Sauermann 2750 when pumping water 1 meter creates a noise of 32 dB, and Mini Orange only 23 dB. Orange leadership.
5. Weight and dimensions: Sauermann 2750 and Mini Orange are approximately the same in size, the weight is also almost identical - both devices weigh within 300 grams
6. Mini Orange also wins in terms of maximum injection, which in this device is 10 m, while Sauermann 2750 has only 6 m.

As you can see, the Mini Orange surpasses the Sauermann 2750 in almost all parameters, but we assure you that in practice you will not notice significant differences between them.

For the purpose of effectively controlling the level of surface water and ensuring that excess liquid is pumped out, it is customary to use drainage pumps. One of the world leaders in the production of this equipment is the Italian concern Pedrollo. A distinctive feature of its pump is the presence of a low residual water level during pumping. Some of them show a 2 mm residual liquid level, that is, they allow it to be pumped out virtually dry.

Obtaining an economic effect from pumping equipment begins with the stage of its acquisition. According to studies conducted by the US Department of Energy, over 65% of pumps are selected incorrectly. A similar situation is observed in Russia. Often, purchased equipment has insufficient or excessive capacity, and electric motors operate with constant underload or overload. With an illiterate choice of the pump, its parameters during operation go beyond the working areas of the characteristic. In this case, there is a violation of the normal course of work processes:

Conversely, a drain pump that is tailored to the specific application helps ensure long-term trouble-free operation and minimize costs. What aspects should be considered when choosing a drainage pump?

Characteristics of the working environment

The characteristics of the purchased pumping equipment must ideally match the operating conditions: climatic factors, temperature, physical properties and chemical activity of the pumped medium. It should be remembered that such equipment is intended for pumping out significant volumes of water, usually containing no more than 5–10% of mechanical impurities. It is recommended to install mesh filters in front of the drainage pumps to prevent large particles from entering the working bodies.

Diameters of solids in the pumped medium for Pedrollo drainage pumps must not exceed:

For all Pedrollo drainage models, the operating temperature of the liquid is not allowed to exceed +40 °C. An exception is the RX-VORTEX series, for which the operating temperature can reach +50 °C.

As for the chemical activity of the working medium, all Pedrollo drainage series are designed for pumping light polluted effluents that do not have chemical aggression to the materials of the pump construction.

Thus, the objects on which these pumps can be operated are: flooded basements, garages, storage rooms, rainwater runoff and ponds without a thick silt layer, provided that the pump is fixed on a solid surface (base plate). They should not be used in construction pits with a sand-gravel mixture, sewage wells with thick silt deposits, because in this case the drain pump will clog and its thermal protection will turn on.

Scope of use of drainage pumps

Drainage pumping equipment is widespread. It can be used:

Emptying level

An important characteristic of drainage pumping equipment is the level of emptying. The minimum level of emptying is demonstrated by the TOP-FLOOR series, in this case it is only 2 mm from the bottom.

Other series have the following emptying levels:

Calculation of the performance of the drainage pump

It is unlikely that drainage pumps will help save the facility from a serious accident on pipelines or from complete flooding. For pumping out small bays, the minimum productivity is enough. Such has, for example, the TOP-FLOOR series with a flow rate of up to 160 l / min., which is also able to provide pumping out virtually dry (2 mm from the bottom).

If the pump is to be equipped drainage system, then it is required to establish the intensity of the inflow of the pumped liquid. The method for calculating this parameter is simple.

The volume of supply water (To) is created from the volume of drainage water (Tdr), the volume of storm water (Td) and the volume of wastewater (Tst):

Stormwater volumes are defined as follows: Td = U * Y * C, where

It suffices to accept the following parameters of the nominal intensity of the shower:

The following consumption coefficients are accepted:

The catchment area (C) refers to the areas from which runoff enters the drainage system.

Wastewater inflow (Tst) depends on the number of people living in the house: Tst = 150 l / day for each person.

Thus, having determined the volumes of supply water, you should choose the appropriate model of the drainage pump. At the same time, its performance should be higher than the calculated maximum value. The excess limits are limited by the throughput of pipelines.

Consumers have the opportunity to choose Pedrollo pumps with different capacities:

Head calculation

To calculate the minimum required pump head, it is necessary to determine the distance over which water should be diverted and the height of its expected rise. The height is determined by the difference in height between the location of the pump and the point of discharge. In this case, it is necessary to take into account the pressure loss in the process of overcoming the hydraulic resistance of the pipeline. As a rule, the value of this indicator when crossing horizontal sections of pipelines is equal to 1 meter of pressure per 10 m of the pipeline (coefficient = 0.1).

No one will argue that water is vital for a person. However, there are times when it causes a lot of trouble. During the period of snowmelt or heavy rains, excess water can cause a lot of damage to buildings, washing away the foundation and flooding basements. An indispensable assistant in such a situation can serve as a drainage pump. With its help, it is not difficult to pump out excess water, even with a certain degree of pollution.

Therefore, such a unit is indispensable in the suburban economy. In addition, it can be used to pump water from any reservoir, whether it be a pool or a pit. Therefore, when purchasing a unit, it is worth considering how to choose a drainage pump so that it performs all the tasks with maximum efficiency.

The main components of the drainage pump

If you don’t particularly “dig” into the mechanism, the drainage pump device consists of an engine and a pump assembly, which are placed in a sealed housing.

It is made mainly of stainless steel or fairly durable plastic. The impeller of the engine is equipped with blades and fixed on the rotor shaft.

The size of the openings of the suction grate determines the maximum size of solid particles allowed to be contained in the pumped medium.

The pump unit sucks water through special holes, the diameter of which determines the maximum size of solid particles allowed to be contained in the pumped liquid. Most manufactured pumps are equipped with a float switch.

If you want to know how a sump pump works, watch the video of the process.

Such units can be used for both domestic and industrial work. Before deciding which drainage pump to choose, you need to find out the preferential conditions of use. This is necessary in order to determine the configuration of the mechanism. The main characteristics that you should pay attention to when choosing a drainage pump are:

• finding the suction hole; For professional units, this feature is unimportant. They can be placed in any position. For household pumps, it is better if the hole is located at the bottom. This will allow maximum pumping of water from the bottom of the tank.
• pump housing; For industrial applications, mechanisms with a cast-iron body are produced. They are quite reliable, but have a lot of weight. Household pumps due to the body made of steel or plastic are more compact and light. However, they have sufficient power to perform their functions.
• working chamber; For pumping water without impurities, its size is unimportant. For liquids containing large fractions, the size of the working chamber must be wide enough for their passage. Otherwise, the mechanism of the unit may be damaged.
• unit design; industrial models have a more complex design, which requires the involvement of a specialist for filter replacement and maintenance. Maintenance of household pumps is carried out independently.
• suction device; centrifugal mechanism for suction allows the pump to be used for pumping water with solids without reducing power.

What material should the parts and body be made of?

This is an important characteristic for such a unit. Not only the price of the pump depends on it, but also the reliability and service life of it. According to the material of manufacture, pumps are:

• completely plastic; They are the least durable, but are cheaper than other analogues.
• plastic with stainless steel operating mechanism; Thanks to this, the wheel of the unit is not exposed to aggressive environments and corrosion.
• stainless steel or cast iron; Leading the rating of drainage pumps in terms of durability due to the resistance of all parts to any damage.

Blade-type units are divided according to the material from which the parts are made. The blades for the pump are made:

• stainless steel; cheaper option.
• technopolymer, which is more resistant to corrosion and wear, but also more expensive.

Classification by installation method

According to the installation method, drainage pumps are divided into:

• superficial; They pump out water even from great depths. Mainly used in pumping stations for connection to a well or well.
• semi-submersible; The body of the unit is partially immersed in the pumped liquid. It is used for pumping water from cellars or small reservoirs.
• submersible; The pump is completely immersed in the pumped medium. Used to drain pools and basements.

Devices that extend the life of the pump

During the operation of the drain pump, the engine may overheat, which is fraught with damage to the unit. Also, its operation at a too low level of the pumped medium affects the service life of the mechanism. A thermal relay will help to avoid overheating of the engine, turning off the unit when the temperature is exceeded.

The drain pump with a built-in float switches off automatically when the liquid drops during pumping. It can also turn on automatically when the room is filled with water. This will help to avoid significant flooding in the absence of owners during the flood.

Switching on and off sensors in pumps with an aquasensor control the operating mode of the unit, the devices are regulated independently of each other

Developments in this area do not stand still, and units with the new aquasensor technology are already on sale. Thanks to the regulator, you can set the required allowable water level to turn the unit on and off. In this case, the minimum level can be set to 5 mm. Such pumps can be installed in narrow tanks where the operation of a float switch is not possible.

What are the specifications to focus on?

Performance is the most important aspect

To determine the required pump performance, it is necessary to find out the scope of the proposed actions. That is, how much water must be pumped out in a certain period of time. For example, household drainage pumps are capable of pumping out no more than 180 liters per minute. For the tasks of pumping excess water from the basement or draining the pool, such pumps are quite suitable.

However, you need to be aware that the higher the upper reset point, the greater the loss in performance.

Required device pressure

To calculate the pressure required to perform a specific task, you need to know the height and distance over which water is supplied. Height is defined as the distance between the submerged level of the pump and the point where the water exits the nozzle. This takes into account that there is a loss of one meter of pressure for every ten meters of hoses or pipelines.

Pump selection depending on the pumped medium

Each pump has a specific specification, which indicates the size of the impurities contained in the water, which this unit is able to pass without reducing performance.

If the aggregates are distributed according to these characteristics, we obtain the permissible size of impurities:

• up to 5 mm; used for clean or lightly contaminated liquids. Suitable for drainage of rain tanks, pools.
• 5-25mm; It is used for medium contaminated liquids with impurities not exceeding 25 mm. With their help drain pits or wells.

25-38mm

; Used for dirty, rain and melt water.

For dirty water, pumps are used that allow impurity sizes from 25 to 38 mm

Typically, household drainage pumps for water are used in environments with a temperature of no more than 40º. Therefore, they are not suitable for pumping hot water. For such functions, industrial units are chosen that can even cope with such a task.

On the market, drainage pumps for summer cottages are presented in a wide range. Therefore, if you need to perform several tasks: drain the pool and pump out water from the basement, you do not need to purchase a unit for each process separately. It is enough to choose one, but a reliable pump. In this case, you should focus on the most time-consuming of the processes.