Circulation pump for heating system: characteristics, installation. How to choose a circulation pump for a heating system?

The principle of functioning of a traditional heating system in a small house is based on circulation through the coolant pipeline. For buildings whose area can exceed 100 square meters, such a method of heating will prove ineffective. This is explained by the fact that natural circulation promotes the creation of pressure in the pipeline, which does not exceed 0.6 mPa. This is too small for houses that have two or three floors.

Necessity of the pump

Increase the strength and speed of circulation in the system can be one of two ways. The first involves laying a pipeline of impressive diameter, while the second involves the use of special equipment. These are circulating pumps for the heating system of a private house. The first option is quite expensive, since the cost of the pipe is high.

Pump selection by design type

Before choosing a circulation pump for a heating system, it is necessary to familiarize yourself with the design features of these devices. On the market you can find two types of pumps, which are conditionally called dry or wet.

Characteristics of dry type equipment

This type of equipment does not involve direct contact with the coolant of the working part of the rotor, since the element is protected by sealing rings. Coal agglomerate, ceramic, high-quality steel or alumina can be used to produce the described constituents. This will depend on the type of coolant used. Pumps circulating for home heating systems are started and initiate the movement of the rings towards each other. The parts have a polished surface in which they come into contact and create a layer of water film. Such a connection is created by the difference in pressure levels. Springs press the rings against each other, which contributes to the fact that the elements are adjusted to each other as they wear out without outside interference. Before choosing a circulation pump for a heating system, you need to know that the life of the rings is about 3 years, which is more durable than the stuffing box packing. The latter involves periodic cooling and the presence of lubricant.

Working capacity

If we talk about the efficiency of pumps of this type, then it can be 80%. If you are not ready for a sufficiently high level of noise, then do not purchase such a device, otherwise it will require a separate room. A circulating pump for a heating system, whose reviews are consonant with the characteristics, for this reason is not chosen so often.

Features of the wet type pump

If the equipment is wet type, then the impeller acts as the working motive part, which is immersed in the coolant. The latter serves as the engine coolant and lubricant. The electrical component of the motor is protected from water by a glass made of stainless steel. It is installed between the stator and the rotor. The role of the material for the production of the rotor is ceramics. Then, as the basis of the bearings is graphite. The body of the equipment can be made of bronze, brass or cast iron. Before choosing a circulation pump for a heating system, it is necessary to know that wet-type units have a sufficiently low noise level. Such equipment has a long service life, during which no maintenance is required. If such a need arises, then the repair will be carried out quite simply, this applies to the settings that any master can produce. If you are thinking about how to choose a circulation pump for a heating system, it is important to pay special attention to the efficiency. In wet type of similar equipment, the capacity is lower by 30%.

Is it worth choosing a wet type pump?

Wet circulating pump for heating systems, the characteristics of which are presented in the article, is characterized by the convenience of modular assembly. This indicates that at any time the owners will be able to replace the failed part with a new one. From a single coil unit, you can simply remove the accumulated air. If you pursue the goal of uninterrupted and continuous operation of the equipment, then it is necessary to mount the shaft strictly horizontally, which will ensure access of the coolant to the bearings. Water in this case serves as a lubricant.

Basic selection criteria for pumping equipment

If you decide to choose a circulating pump for heating systems, the characteristics of which are presented above, you must first pay attention to the level of performance. The calculation method is simple enough. The power of the boiler equipment should be equated to the volume of the heat transfer medium per minute. Thus, if the plant's capacity is 35 kW, then 35 liters of water will pass through it. The next step is to determine the water flow in a separate section of the circulation. To do this, use information about the power of the radiators, which is known, and then equate the data. Choosing the pump capacity, we can assume that in a length of 10 meters you need to create a pressure of 0.6 cm. The selection of the circulation pump for the heating system can be made precisely on this principle. This indicates that the normal functioning of a 100-meter pipe will be provided with a head of 6 meters. It only remains to choose the pumping equipment, the technical capabilities of which will ensure the given conditions.

Selecting the location of the pump

After acquaintance with the information on how to choose a circulation pump for heating systems, you can purchase equipment and start the practical part. The pump can be installed on the supply line after the boiler equipment and safety group. As an alternative solution is mounting in front of the boiler on the return line. Part of the masters advise to install the equipment on the first principle, while the other part - on the second. In practice, the location does not matter and does not affect the functioning and power of the system. It is also erroneous to say that due to the low temperature of the return the device will last for a longer time. Quite often the device is installed on the return line, which is explained by the fact that if a malfunction is detected and the boiler equipment overheats, the coolant in the tank boils. The steam mixture will be injected into the system. If the steam enters the pump, the pumping process will be stopped, and the coolant will stop moving in the network. The boiler may explode if such a situation arises.

Features of installation work

If you are thinking about how to choose a circulation pump for heating systems, you can read the information presented above. Whereas if you are at the stage of installation, it is important to follow a number of rules, among them, it should be emphasized that the equipment can work in both horizontal and vertical position. At installation it is necessary to observe a direction of a stream of the heat-transfer medium which is specified on the case. When installing the equipment, the master must take into account the orientation of the pump in space. It must be installed in such a way that its rotor is located in a horizontal position.

You must consider during installation that the pump can be removed for repair and maintenance after installation. Calculation of the circulation pump for the heating system is presented above, whereas the installation work is an easier task. The unit must be mounted on the bypass line, but the crane is installed directly. When it is turned off, the system will continue to function without forced circulation. If the installation is conducted in an open system, then a strainer, also called a sump, is preferable to install on the bypass, but it must be done after the screen. If it is a question of a pressure network, the mudman is located in front of the bypass. When tying the solid fuel boiler, it must be mounted before the three-way valve.

Tips of the master

When the selection of the circulation pump for the heating system has been completed, installation work can begin. The unit should not be installed in such a way that the terminal horizontal box is facing down. If there are no other options, then you must turn off the four screws to fix the case, and then turn the equipment 180 degrees along with the box. After that, the screws are installed into place.

Additional nuances of installation

Calculation of the circulation pump for the heating system can be made according to the above recommendations. During installation work, it is important to observe one more delicate moment. It lies in the question of the version of the scheme. If in it forced circulation of water is conceived from the beginning, then there is no sense in setting the bypass. This is because the coolant without a pump will not flow anyway, since there is no corresponding bias. In this case, the unit can be installed in the return pipeline between the boiler and the expansion tank. A circulating pump for heating systems, the installation of which must be carried out according to the presented technology, should assume the presence of a bypass line only in the case when the system assumes samotec. In some cases, instead of a ball valve on a straight line, a check valve of the petal variety is installed. During the operation of the pump, the pressure will be supported by the petal, and the straight line will be closed. After the power failure, the pump will stop, the pressure will drop, while the valve will be open. This will automatically translate the system into free circulation.