Max. particle size
The largest size of solids in the pumped water that the pump can handle without failure. It is one of the parameters characterizing the unit's ability to work with dirty water (along with the content of mechanical impurities, see below): the larger the particles, the more reliable the pump and the lower the likelihood of it breaking down due to pollution. This point is especially relevant for recently drilled wells, where the water has not yet had time to clear.
Mechanical impurities
The largest amount of mechanical impurities in the pumped water, which the pump can handle normally. When used with dirty water, this parameter should be taken into account along with the maximum particle size (see above): if the impurity content is too high, the pump may fail even if the individual particle size does not exceed the norm.
Suction system
— Single stage. Suction system with one impeller or similar element. Although this design loses to multistage in terms of efficiency and power, at the same time, its characteristics are quite enough for most entry-level and mid-level pumps; at the same time, single-stage units are simpler and cheaper.
— Multistage. This suction system consists of several impellers (or other similar parts that directly provide suction). Such pumps are noticeably superior to single-stage ones, they provide powerful pressure and are less sensitive to impurities. At the same time, multistage systems are quite expensive.
Number of suction stages
Number of suction stages.
Single-stage systems assume the presence of one impeller or other similar element, while multi-stage systems — several. The latter makes it possible to obtain a strong water pressure with an overall compact size.
Power consumption
The power consumed by the pump motor during operation. A more powerful engine can provide more head and performance, but these parameters are not directly related: two models of similar power can differ markedly in practical characteristics. Therefore, this parameter is secondary, and more or less unambiguously it describes only the class of the unit as a whole — powerful engines are typical for high-end performant models. But what this characteristic directly affects is the actual power consumption; and with it, in turn, are connected not only to electricity bills but also connection requirements.
Impeller material
The material from which the pump impeller is made.
A wide variety of materials are used in modern well pumps. However, the manufacturer, usually, chooses the option so that the strength, reliability, resistance to pollution and other key features of the wheel correspond to the required characteristics of the pump and its level as a whole. In addition, the same material may have several varieties that differ markedly in characteristics; this is especially true for technopolymers and thermoplastics, but most metallic materials such as stainless steel or brass also come in several grades. All this means that when choosing a pump, it makes sense to look first of all at performance characteristics, price category, reviews and other practically significant information, and the material of the impeller is of secondary importance.
