Comparison Pedrollo 3CP 100E vs Pedrollo 3CRm 100

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.

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.

— Single-stage. Suction system with one impeller or similar element. Although such a design loses to a multistage one in terms of efficiency and power, at the same time, its characteristics are quite enough for most tasks; while single-stage pumps are simpler and cheaper. Due to all this, this option is used in most modern units.

— Multistage. This suction system consists of several impellers (or other similar parts that directly provide suction). Such pumps are significantly superior to single-stage ones, they provide powerful pressure and are less sensitive to impurities. At the same time, in fact, all these advantages are needed relatively rarely, and multistage systems are quite expensive. Because of this, they are used in a relatively small number of pumps — they are mainly powerful models designed for situations where one suction stage is not enough.

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.

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.

An indicator that determines the degree of protection of dangerous (moving and current-carrying) parts of the hardware of the pump from adverse effects, namely solid objects and water. Since pumps, by definition, are used for pumping liquids, and many of them can normally pass quite large particles, in this case, we are talking about protection against moisture and foreign objects from outside.

The level of protection is usually indicated by a marking of the letters IP and two numbers, the first of which indicates protection against the effects of solid objects, and the second — against the ingress of water.

For the first digit, each value corresponds to the following protection values: 1 — protection against objects with a diameter of more than 50 mm (large body surfaces) 2 — against objects with a diameter of more than 12.5 mm (fingers, etc.) 3 — against objects more than 2.5 mm (most tools) 4 — against objects larger than 1 mm (virtually all tools, most wires) 5 — dust-proof (total protection against contact; dust can enter, but does not affect the operation of the device) 6 — dust-proof (case with full dust protection and contact).

For the second digit: 1 — protection against vertically falling drops of water 2 — against drops of water with a deviation of up to 15° from the vertical axis of the device 3 — against drops of water with a deviation of up to 60° from the vertical axis of the device (rain) 4 — against splashes from any direct...ion 5 — from jets from any direction 6 — from sea waves or strong water jets 7 — short-term immersion to a depth of up to 1 m (without the possibility of continuous operation in immersed mode) 8 — long-term immersion to a depth of more than 1 m (with the possibility of permanent operation) in immersed mode).

Note that in some cases one of the numbers can be replaced by the letter X — this means that official certification for the corresponding parameter has not been carried out. In pumps, X is usually put in place of the first digit, because. a high degree of moisture resistance (and for submersible models, for example, it must, by definition, correspond to 8) means a high degree of protection against solid contaminants.

The material from which the pump housing is made. It is a structural element in which the working mechanism (impeller or auger) is installed. Note that the motor casing can be made of a different material — this is not important in this case; and in water pumps with the engine (see “Power source”), we are talking about the casing of the pump itself, and not about the support frame in which it is fixed.

The following options are most popular nowadays:

— Plastic. Inexpensive material that perfectly resists moisture and is not subject to corrosion. However, the reliability of plastic as a whole is not very high; the exception is special high-strength grades, but they are extremely rare in pumps (when strength is needed, metals are usually used). So plastic housing is mainly equipped with relatively simple and affordable models that are not designed for serious loads.

— Cast iron. An extremely popular material nowadays: cast iron is strong, reliable, durable and at the same time has a relatively low cost. However, in terms of corrosion resistance, this material is inferior to stainless steel (see below). Nevertheless, subject to the rules for operating the pump, the service life of the cast-iron housing is not inferior to the service life of most of the main components of the unit. Also note that such cases are quite massive, which makes transportation difficult; however, in some cases, a large weight is an advantage: it helps to dampen vibrati...ons.

— Stainless steel. By the name, one of the key advantages of stainless steel is high resistance to corrosion — and, accordingly, reliability and durability. On the other hand, this material also costs a little more than the same cast iron. The weight of such housing is somewhat less — this, again, can be both an advantage and a disadvantage, depending on the situation.

— Aluminium. Premium material. The aluminium alloys used in today's pumps are light, strong, durable, and virtually impervious to moisture, but cost accordingly.

— Brass. A fairly rare option found in some models of surface pumps. Brass is strong enough, reliable and resistant to moisture, but in most cases, it does not have key advantages over the same stainless steel or aluminium but costs a little more.

— Bronze. Another material similar to the brass described above is durable and practical but rarely used.

— Ceramics. A material found exclusively in sewage pumps in the form of toilet bowls (see "Pump design"). Most often, ceramics means vitreous china or more expensive and durable vitreous china — that is, the same materials as in ordinary toilets without built-in pumps.

The material from which the main working element of the pump is made is an impeller, an auger or a membrane. This part is in direct contact with the pumped liquid, so its specs are key to the overall performance and capabilities of the pump.

— Plastic. Plastic is low-cost, and it is not subject to corrosion. It is believed that the mechanical strength of this material is generally low, and it does not tolerate contact with solid impurities. However, today there are many varieties of plastic — including special high-strength varieties that are suitable even for working with heavily polluted water or sewage. So plastic impellers/augers can be found in a variety of types of pumps; the overall quality and reliability of such parts, usually, depend on the price category of the unit.

— Cast iron. Solid, durable, reliable and, at the same time, relatively inexpensive material. In terms of corrosion resistance, cast iron is theoretically inferior to more advanced alloys like stainless steel or aluminium; however, subject to the operating rules, this point is not critical, and the service life of cast iron parts is no less than the total service life of the pump. The unequivocal disadvantages of this option include a large mass, which slightly increases the energy/fuel consumption during operation.

— Stainless steel. By the name, one of the key advantages of stainless steel is high resistance to corrosion — and, accordingly, reliability and durabili...ty. Such an alloy is somewhat more expensive than cast iron, but it also weighs less.

— Aluminium. Aluminium alloys combine strength, reliability, corrosion resistance and low weight. However, such materials are quite expensive — more expensive than the same stainless steel, not to mention cast iron.

— Brass. The varieties of brass used in pumps are distinguished by high strength and hardness, as well as insensitivity to moisture. Such materials are quite expensive, but this price is fully justified by the mentioned advantages. Therefore, in certain types of pumps — in particular, surface models and pressure tank units — brass impellers are very popular.

— Bronze. A material similar in many properties to the brass described above. However, bronze is used much less frequently — in particular, due to a slightly higher cost.

— Steel. Varieties of steel that are not related to stainless steel are used extremely rarely — in certain models of pumps for chemical liquids. At the same time, steel is usually used as a base in such parts, and a coating of fluoroplastic or other similar material is applied to it to protect it from corrosion.

— Silumin. Silumins are called aluminium alloys with the addition of silicon. For several reasons, such materials are rare in pumps, and mainly among relatively inexpensive models.

— Rubber. Material traditionally used for diaphragms in vibratory pumps (see “Pump type”).