Pressure in the heating system. Working pressure in the heating system

Normal pressure in a closed heating system is very important. First, it is a warm room in the winter, and secondly, the normal operation of all components of the boiler. But not always the shooter is in the right range, and the reasons for this may be mass. Increased and reduced pressure in the heating system leads to the blocking of the pump and the lack of warm batteries. Let's talk in more detail about how many atmospheres should be in our pipes and how to fix typical problems.

Some general information

At the design stage of the heating system , manometers are installed in different places. This is necessary in order to control the pressure. When the device detects a deviation from the norm, it is necessary to take any action, a little later we will talk about what to do in a specific situation. If you do not take any measures, then the heating efficiency falls, and the life of the same boiler is reduced. Many know that the most detrimental impact on closed systems is hydraulic shock, for the damping of which expansion tanks are provided. So, before each heating season it is desirable to check the system for weaknesses. This is done quite simply. It is necessary to create excess pressure and see where it will manifest itself.

Low and high pressure in the system

Often the pressure drop in the heating system is due to several factors. Firstly, it is the leakage of the coolant, which is the most common cause of lowering the number of atmospheres. Leakage is most often located at the junction of parts. If there is not, then, most likely, the problem is in the pump. The scale in the heat exchanger is another reason for lowering the pressure in the system. The same applies to the physical wear of the heating element. But the increase in pressure happens due to the formation of an airlock. Also, the cause may be impeded movement of the carrier through the pipes due to obstruction in the filter or sump. Sometimes due to failures of the automatic system, excessive system make-up occurs, in this case the pressure also rises.

How to fix the situation at the edge?

It's all very simple. First, you need to look at the manometer, which has several characteristic zones. If the arrow is in the green, then everything is fine, and if it is noticed that the pressure in the heating system is falling, the indicator will be in the white zone. There is still red, it signals a rise. In most cases, you can manage on their own. First you need to find two valves. One of them serves for injection, the second - bleeding the carrier from the system. Then everything is simple and understandable. If there is a lack of media in the system, it is necessary to open the discharge valve and follow the gauge installed on the boiler. When the arrow reaches the required value, close the valve. In the event that a bleed is needed, everything is done in a similar way with the only difference being that you need to take a vessel with you to where the water from the system will merge. When the gauge needle shows the norm, twist the valve. Often this is the "treatment" of the pressure drop in the heating system. And now let's go further.

What should be the working pressure in the heating system?

But to answer this question in a few words is quite simple. Much depends on which house you live in. For example, for the autonomous heating of a private house or apartment is often considered normal 0.7-1.5 atm. But again, these are approximate figures, since one boiler is designed to work in a wider range, for example, 0.5-2.0 Atm, and the other in smaller. It is necessary to look at the passport of your boiler. If there is none, stick to the golden mean - 1.5 Atm. The situation is completely different in those houses that are connected to central heating. In this case, you need to be guided by the floor. In 9-floors, ideal pressure is 5-7 Atm, and in high-rise buildings - 7-10 Atm. As for the pressure, under which the carrier is fed into buildings, it is most often 12 Atm. Lower the head can be with the help of pressure regulators, and increase - by setting the circulation pump. The latter option is extremely relevant for the upper floors of high-rise buildings.

How does carrier temperature affect pressure?

After a closed water supply system has been installed, a certain amount of coolant is pumped in. As a rule, the pressure in the system should be minimal. This is due to the fact that the water is still cold. When the carrier is heated, its expansion will occur and, as a consequence, the pressure inside the system will increase somewhat. In principle, it is quite reasonable to regulate the number of atmospheres by regulating the water temperature. At present, expansion tanks are used, they are also hydroaccumulators that accumulate energy inside themselves and do not allow for an increase in pressure. The principle of the system is extremely simple. When the working pressure in the heating system reaches 2 Atm, an expansion tank is activated. The accumulator takes away excess heat carrier, thereby maintaining the pressure at the required level. But it happens that the expansion tank is full, there is now no surplus of water, in this case a critical overpressure (more than 3 Atm.) Can appear in the system. To save the system from destruction, a safety valve is activated , which removes excess water.

Static and dynamic pressure

If we simply explain the role of static pressure in a closed heating system, we can put it like this: this is the effort with which the liquid presses the radiator and the pipeline, depending on the height. So, for every 10 meters there is +1 Atm. But this only applies to natural circulation. There is also a dynamic pressure, which is characterized by pressure on the pipeline and radiators while driving. It should be noted that when installing a closed heating system with a circulation pump, static and dynamic pressure are padded, taking into account the peculiarities of the equipment. Thus, the cast-iron battery is designed for operation at 0.6 MPa.

Diameter of pipes, and also degree of their deterioration

It must be remembered that you need to consider the size of the pipe. Often tenants set the diameter they need, which is almost always somewhat larger than the standard sizes. This leads to the fact that the pressure in the system is somewhat reduced, which is due to the large amount of coolant that will fit into the system. Do not forget that in the corner rooms the head in the pipes is always smaller, since this is the most remote point of the pipeline. The pressure of the pipes and radiators influences the pressure in the house heating system. As practice shows, the older the battery, the worse. Of course, every 5-10 years can be changed by everyone, and it is inappropriate to do this, but from time to time it is not a problem to conduct preventive maintenance. If you are moving to a new place of residence and you know that the heating system is old there, then it is better to change it immediately so you will avoid many troubles.

About Leak Testing

It is mandatory to check the system for leaks. This is done so that the heating work is efficient and has no malfunction. In multi-storey buildings with central heating, cold water is often used. In this case, if the water pressure in the heating system falls by more than 0.06 MPa in 30 minutes or 120.02 minutes is lost, it is necessary to look for gust sites. If the indicators do not go beyond the norm, then you can start the system and start the heating season. Checking with hot water is carried out immediately before the heating season. In this case, the carrier is supplied under pressure, which is the maximum for the equipment.

Conclusion

As you can see, it's quite easy to understand this question. If you use autonomous heating, the working pressure in the system should be approximately 0.7-1.5 Atm. In other cases, much depends on the number of storeys of the building, as well as the degree of wear of batteries and radiators. In all cases, it is necessary to take care of installing an expansion tank, which eliminates the occurrence of water hammers and, if necessary, lowers the pressure. Remember that it is desirable at least once in 2-3 years before the heating season to clean the pipes of scale and other decomposition products.