Suitable for
— Pure water. Pure water pumps conventionally include all models for which the maximum particle size (see below) does not exceed 5 mm; in addition, the permissible content of mechanical impurities (also see below) for them is also small. Accordingly, many of these models are capable of pumping water with impurities normally, but they are not suitable for heavily contaminated liquids.
— Dirty water. This category includes pumps capable of working with large mechanical impurities — more than 5 mm. Note that some manufacturers position such models as mixed-use units, “for dirty and clean water”. However, they have a reinforced design, the presence of a grinder capable of grinding the particles mentioned, a reinforced body, an increased diameter of pipes, increased power, etc. .P. The main difference between such pumps and waste water pumps (see above) is the impossibility of working with high-viscosity liquids.
— Waste water. Waste water pumps are in many ways similar to the models for dirty water described above because they also have to deal with large particles. The main difference is the allowable size of these particles — it is 50 mm or more; in addition, the entire design of such pumps is created based on the high viscosity of the pumped liquid.
— Chemical liquids. Pumps designed to work with chemical liquids are distinguished primarily by the use of highly resistant materials in the design — usually polymers. Due to this, they can endur...e working with aggressive substances without consequences — acids, alkalis, oil products, solvents, liquefied gases, etc. In addition, other special solutions are often used in “chemical” pumps, which allow the safe pumping of flammable and explosive materials, very cold, hot, viscous liquids, etc. The main scope of such units is the industry — both chemical and oil, food, etc. Note that different models can be designed for different types of substances.
Maximum performance
The maximum volume of water that the device can pump in a certain amount of time. It is one of the key specs of any pump because characterizes the volume of water with which the device can work. At the same time, it does not always make sense to pursue maximum performance — after all, it significantly affects the dimensions and weight of the unit.
Some formulas allow you to derive optimal performance values for different situations. So, if the pump is designed to supply water to water intake points, its minimum required performance should not be lower than the highest total flow rate; if desired, a margin of 20-30% can be added to this value. And for sewer models (see "Suitable for"), everything will depend on the volume of wastewater. More detailed recommendations for choosing a pump depending on performance can be found in special sources.
Maximum head
The maximum head generated by the pump. This parameter is most often indicated in meters, by the height of the water column that the unit can create — in other words, by the height to which it can supply water. You can estimate the pressure created by the pump using a simple formula: every 10 m of head corresponds to a pressure of 1 bar.
It is worth choosing a pump according to this parameter, taking into account the height to which it should supply water, as well as adjusting for losses and the need for pressure in the water supply. To do this, it is necessary to determine the difference in height between the water level and the highest point of water intake, add another 10 to 30 m to this figure (depending on the pressure that needs to be obtained in the water supply), and multiply the result by 1.1 — this will be the minimum pressure required.
Max. pressure
The highest pressure that the pump is capable of creating during operation. This parameter is directly related to the maximum head (see above); however, it is less obvious, and therefore, it is indicated rarely.
Maximum particle size
The largest particle size that the pump can handle without problems. This size is the main indicator that determines the purpose of the device (see above); and in general, the larger it is, the more reliable the device, the lower the risk of damage if a foreign object enters the suction line. If the risk of the appearance of too large mechanical impurities is still high, additional protection can be provided with filters or grids at the inlet. However, such a measure should be considered only as a last resort, because from constant exposure to solid particles, the grids become clogged and deformed, which can lead to both clogging of the line and filter breakthrough.
Ejector
The presence of an ejector in the design or delivery set of the pump.
The main purpose of the ejector is to increase the effective suction height. Its action is based on the fact that part of the water pumped by the pump is sent back down to the intake point; this water in some way "pushes" the water in the main suction line. Thanks to this, the suction height can be increased from 7-8 m, available without an ejector, to 15-20 m. The main disadvantage of this device is a rather high noise level.
Maximum power
Rated power of the pump motor. The more powerful the engine, the higher the performance of the unit, usually, the greater the pressure, suction height, etc. Of course, these parameters largely depend on other features (primarily the pump type, see above); but models similar in design can be compared in terms of power.
Note that high power, usually, increases the size, weight and cost of the pump, and also implies high costs of electricity or fuel (see "Power source"). Therefore, it is worth choosing a pump according to this parameter taking into account the specific situation; more detailed recommendations can be found in special sources.
Mains voltage
The supply voltage for which the pump with an electric motor is designed is electric or battery (see "Power source").
— 230 V. Voltage of ordinary household mains. Most pumps with this power supply can work directly from the socket, only the most powerful models (3 kW and above) require a special connection format (directly to the switchboard). However, 230 V mains are relatively poorly suited for high-power units. Therefore, this type of power supply is found mainly among electric pumps of low and medium power, designed mainly for domestic use.
— 400 V. Power supply from three-phase 400 V mains is suitable for electric pumps of any power — including heavy industrial equipment. However, this type of power supply is also found among relatively "weak" models — including 400 W and below. This is because a three-phase connection has several general advantages over a single-phase one: in particular, such mains are better able to withstand high loads (including power surges during motor starts), they are better suited for long-term continuous operation, and also allow more accurate accounting of consumed energy. If there is access to a 400 V mains at the pump installation site, it is most likely that such a power supply will be optimal.
— 12 V. A value that is practically not found among mains pumps, but quite popular in battery models (see "Power source"). In this case, voltage does not affect performance, but it may be useful when looking for a...replacement/replacement battery or third-party charger. At the same time, we emphasize that the use of 12-volt car batteries with pumps is highly discouraged: such energy sources are designed for a specific format of operation, and their abnormal use is fraught with accidents.
— 18 V. Another version of the operating voltage found in battery pumps; has no fundamental differences from the 12 V described above.
Engine type
Type of motor installed in the electric pump (see "Power source").
— Asynchronous. The most common type of electric motor nowadays. Asynchronous motors are simple in design and inexpensive, while they are very reliable. Their main disadvantage is the difficulty in regulating the rotational speed and the dependence of this frequency on the load on the rotor; on the other hand, in most cases, these shortcomings are not critical.
— Synchronous. Without going into technical details, we can say that this type of electric motor is considered more advanced than asynchronous — in particular, due to the ability to adjust the speed easily. At the same time, such units are difficult to manufacture and expensive, so they are rare — mainly in high-end technology, where adjustment accuracy is a key parameter.
