Begins to malfunction. Winter came, the boiler was turned on, but the radiators are not heating up.
It turns out that air has accumulated in the pipes, and plugs have formed that prevent the free circulation of the coolant. The problem can be solved simply if, when designing the circuit, air vents were provided in it, which make it easy to remove gases from the pipes.
There are several reasons why air can enter the heating circuit:
- When filling pipes with water, all cavities are not completely filled.
- Oxygen particles get in when replenishing the coolant during system operation.
- It can be sucked in during the operation of the circuit, if mistakes were made in its design.
- The water contains oxygen in adsorbed form. Over time, it is released, rises up and accumulates at the highest points.
A properly designed circuit ensures stable operation and tight filling during initial pressurized water filling.
The liquid is fed from the bottom up until the required indicators in the system are achieved. At the same time, air from pipes and equipment is gradually displaced.
In an open circuit, it is immediately released into the atmosphere, and in a closed circuit it accumulates in special sedimentation tanks. The oxygen stored in the liquid is usually released within two to three days and also rises up. If no mistakes are made in the project, gases will not linger anywhere, except for the points designated for this, at which air vents are installed.
To some extent, the problem can be mitigated by preliminary deaeration of the water, which will help reduce the oxygen content in it from 30 to 1 gram per ton. It is impossible to determine in advance how gassed the liquid is. Therefore, in any case, even from deaerated water, it is necessary to remove gases. When a liquid is heated, the gases adsorbed in it begin to be released faster, while an increase in pressure inhibits this process.
Why remove oxygen from the water in the heating circuit?
It is already clear that the formation of traffic jams significantly reduces the performance of heating. But there are a few more problems that can be encountered due to the presence of gases in pipes.
Metal in the presence of oxygen tends to oxidize. This process is activated much more strongly if the air dissolved in water acts on the pipe walls, in which the concentration of gases is much higher.
Rust forms in steel devices, due to which the inner diameter decreases, which reduces the rate of circulation of the coolant. With prolonged destructive action, corrosion can lead to damage to the integrity and leakage of pipes.
Therefore, it is very important to monitor the formation of airiness in the batteries and eliminate it in a timely manner. There are practically no such problems.
Methods for dealing with the airiness of the system
To remove the air accumulated in the heating pipes, special devices - air vents. They must be installed on each, including steel, at the outlet of the heating devices or at the highest points of the circuit, where the released oxygen is concentrated.
On the market you can find various modifications of such fittings, the most common are devices made in Italy and Germany. With the same purpose, two fundamentally different types are distinguished.
Handheld devices
Mayevsky's cranes, or manual air vents, are used to discharge the air accumulated in the circuit. They have enough simple design and consists of a screw that covers the needle hole in the brass body.
All parts of the device fit snugly and, when closed, do not let the coolant pass through. The gases are vented through a hole in the side of the housing. Recently, fittings with metric threads have become more popular, which greatly simplifies their manufacture. In various designs, adjustment can be made in several ways:
- unscrew with a screwdriver;
- open using a special square ICMA key;
- turn away with your hands.
Most often, manual taps are installed on radiators by screwing into the upper hole. Such fittings are selected depending on the diameter.
Often these devices are installed on other devices as well. They are attached to heated towel rails using a tee. In two-story houses with top feed, all appliances on the top floor must be equipped with Mayevsky taps.
After filling the system or before the heating season, it is necessary to bleed the accumulated air. To do this, turn the hand valve counterclockwise, and oxygen leaves the device.
Usually one turn is enough, but if a large volume of gases has accumulated, you can tighten the valve another half turn. You need to close it when water begins to come out instead of gases. In systems with forced circulation, the pump is pre-switched off, and after a few minutes the accumulated gases are released. When the pump is running, it is impossible to collect all the air in the place where the tap is attached and the plug will not be removed.
Sometimes manual air vents are found not with a needle stem, but with a metal ball that closes the hole for venting oxygen. The design of the body may also differ, allowing the installation of the crane both straight and at an angle.
Automatic valve
The operation of air vents, which work automatically, is based on the float-valve principle. A float is installed in a brass body, connected by a lever with exhaust valve... The float is constantly floating in the water, while the valve is closed. In case of accumulation of air, the float is lowered and opens the valve. Gas exits to atmosphere through a narrow opening between the float and the body.
Then the reverse process takes place. As the air escapes, the body is filled with a coolant, and the float rises, closing the valve. If the air vent breaks down, liquid does not leak due to the presence of shut-off caps in the structure. An automatic air vent is installed in the system through a special shut-off valve that closes when the device is removed. This makes it possible to produce renovation work without draining water and relieving pressure.
Such devices are installed at the highest points of the system and are located vertically. Most often they are mounted in such critical places:
- on a heating boiler;
- at the top of the riser;
- on collectors;
- on air separators.
More widespread use is hindered by low quality technical water. Small particles floating in the liquid will clog the air vent and the equipment will stop working. A fundamental design change has been made in AFRISO fittings:
- increased hole size;
- the outlet channel is located in the middle of the float.
This design allows the air vent to work more efficiently and regardless of the quality of the coolant, besides, its maintenance and cleaning is much easier.
Which air vent to install
In most cases, when designing a heating system, the owner of the house plans the autonomous operation of the equipment. In this case, it is logical to assume that automatic air release valves are preferable.
But given the problems with the quality of the coolant and the placement of equipment, it is sometimes easier and cheaper to use the manual type. Oxygen from radiators must be vented after filling or topping up pipes with water. In both cases, the work is carried out under the supervision of a person who easily opens the tap to make sure that air congestion no.
Often, both types of air vents are used in the same circuit at the same time. Mayevsky taps are installed on the radiators, and where airiness may appear during operation, on the riser and, - automatic valves. When correct selection the equipment will be provided with autonomous heating operation throughout the entire heating period.
Air vent - a device for bleeding air from the pipeline system. It is based on the principle of a float. The float floats, pressing the needle or plug against the outlet. The air from the heating or water supply system rises up, the float drops, opening the outlet. As soon as the air was out, the float floated up again and blocked the exit. From this, these products are called automatic air vents or air valves. True, there are also air valves in the sewer system, but they perform a different function there.
What is an air vent for? The fact is that air is often an insurmountable obstacle to the passage of water in the water supply, and even more so in heating. Air can defrost radiators or entire radiator heating circuits. Water does not go where there is an airlock, it follows the path of least resistance, that is, through other radiators, other circuits, leaving the air-conditioned heating devices to freeze. Even if half of the radiator is filled with air, then only that part of it through which the coolant passes will heat. If there is air in the boiler, then the uncooled part of the boiler heat exchanger will overheat, which can damage it. The air in the heating system is destructive. It expands much faster and more water, creating a sharp increase in pressure. He creates a lot of troubles. The most dangerous areas of air accumulation are the tops of radiators, other heating devices, the upper sections of pipelines that form loops. It is in these areas that air vents need to be installed. Each radiator, collector, boiler, hydraulic arrow must have its own air vent at the highest point. Manual or automatic air valve is another matter, the most important thing is its availability and regular maintenance.
Many people want to buy a high-quality air vent so that it will last for a long time. Yes, quality plays a big role, but not the main one. The fact is that no matter what the quality air vent, it remains consumable... For their quick replacement, there are even special mounting valves for air vents, so that one can be easily unscrewed and another screwed in its place. The main thing is regular performance monitoring. The plug can stick, stick, get stuck in the vent hole and prevent air release in time. And if you overlook this moment, you can be left without warmth in the house.
For heating radiators, manual air vents or Mayevsky taps are usually used. In rare cases, automatic radiator products are used, but this is extremely rare. Usually, before the start of the heating season, they bleed air from all radiators and forgot about them until spring. Automatic air vents are another matter. They are usually placed where there is a lot of air, where it constantly accumulates and it is rather difficult to manually bleed the air every day. And this is at boilers, on collectors and at the highest points of the heating circuits.
An automatic air vent is always included in the boiler safety group kit along with a pressure gauge and a safety valve. It should always only be in an upright position, the outlet should not be obstructed. If the hole for it is in a horizontal position, then there are products with a horizontal connection.
The most popular air vents are Itap, Emmeti, Far, Oventrop in ascending order of their price and, at the same time, decreasing popularity. Oventrop and Far are of excellent quality, but their price is several times higher than cheap counterparts. They serve several times longer. How lucky here. But several pieces of cheap analogs can last longer than one expensive one.
The air in the heating system is not even bad, it is critical and negatively affects the efficiency of heating the house. And the most unpleasant thing about it is that it is constantly formed in pipes. Therefore, removing it is a never-ending process. That is, a person has to either constantly bleed him manually by means of the Mayevsky crane, or automatically, which is much more attractive. It is for this that such a device as an automatic air vent was created, which is the topic of this article - together with the website stroisovety.org we will understand its design, get acquainted with the varieties and principle of operation, and also tell you about how and where it is installed ...
Automatic air vents in the heating system photo
Automatic air vent: working principle
You will probably be very surprised if I say that Mayevsky's automatic faucet works on almost the same principle as a toilet cistern - in both devices, the float does the main work. In the case of the toilet, the movement of the float closes and opens the needle valve through which the liquid passes, and in the case of automatic air discharge through the needle valve, gas is removed from the heating system. In fact, in such a system, there are only two valve operating positions - the float at the top and the float at the bottom.
Everything is fine, everything works and the air is removed in automatic mode - you no longer need to control this process manually. There is really one "but" - this whole system works only with the vertical position of the float, that is, the automatic air valve itself, which is not always possible to achieve in the heating system. In principle, this is not a problem, since, having comprehended this situation, manufacturers of such devices quickly found a way out, and as a result of these searches, alternative designs appeared - so to speak, varieties.
Types of automatic air vent
In total, there are three types of these devices - despite this, the operation of the automatic air vent, or rather its principle, remains unchanged. In all cases, the same needle valve and the same float that opens and closes it are used - the only difference is in the position of the body relative to the connecting pipe, i.e. threaded connection.
This and all the varieties that an automatic air valve for heating systems can boast of. In principle, more is not needed, since regardless of the various installation conditions, one of them will still work.
Which is better: an automatic machine or a manual Mayevsky crane
No matter how attractive the operation of an automatic air relief valve looks, no matter what advantages it promises, there are still some circumstances that speak not in its favor. Or at least talking about the economic inexpediency of installing the machine. Such circumstances are few, but nevertheless they occur.
Why are there such distinctions, ask? Everything is quite simple - an automatic air vent costs at least 10 times more than a Mayevsky crane. So if you don't really need it, you can refrain from unnecessary expenses. By the way, I completely forgot to say - any automatic air vent can be used in manual mode. To do this, it is additionally equipped with a spool - you just have to press a match or something else thin on its inner pin, and the air will come off. Alternatively, if it is not there, some water will go.
The main problem of living in city apartments is the heating system. Heating is a rather complicated heating scheme for various industrial buildings and residential premises, which is based on the regular maintenance of a comfortable microclimate for living.
Before the start of the heating season, utilities warn every year that the air needs to be vented. In some cases, the cause of air is the release of hydrogen from the water due to peculiar chemical effects.But this problem can be avoided by installing air vents for heating systems. What are these devices, how do they work and why are they needed? This will be discussed further.
Why does air appear in the system?
Air can enter the heating system for a variety of reasons.
The most common among them are:
- when the system is initially filled with water;
- due to poor quality or worn out sealing elements;
- due to water replenishment;
- corrosion inside pipes;
- violation of installation rules when conducting and connecting heating system etc.
When water enters the heating system, it contains a large amount of oxygen, which expands when heated and forms air locks. They, in turn, reduce the pressure in the system and reduce the rate of water circulation. Thus, if air vents for heating systems are not installed in your apartment, then you must manually release the air. If this is not done, then the room will warm up poorly and unevenly, which, in turn, will negatively affect the comfort of living.
Views
There are two types of air vents:
- manual;
- automatic.
Automatic air vents in the heating system are more practical and convenient to use, since they do not require any human action. However, their cost will be higher than manual counterparts. Their installation should be carried out in places where the probability of air congestion is highest. Manual installation is performed on heating radiators.
How do they work?
The principle of operation of the air vent in the heating system depends on the design features of these devices.
Manual air vents (as it is not difficult to guess from the name) require human intervention, while equipment with automatic control you can simply install and forget about it forever, since it will release air on its own as the need arises.
What problems can airing the heating system lead to?
Before talking about how the installation of an air vent in a heating system is performed, let's first understand the main problems that air in heating pipes and radiators can lead to. Air makes it difficult for water to circulate through the system, as a result of which the heating efficiency of the room is significantly reduced. In addition, airing will cause vibrations, which, over time, can lead to physical damage to the heating system at the welding points of individual elements.
The accumulation of air in the pipes will contribute to their rusting and reduce the service life. But the worst problem is the defrosting of the system, which can leave you without heat during the winter.
Design features
Manual and automatic air vents have similar design featuresexcept for some differences.
Both types of devices consist of a channel and a valve, which is responsible for removing air from the heating system. To choose which type of equipment to install in your home, you need to understand how a manual and automatic air vent works.
How does an automatic fixture work?
So how does an air vent in an automatic heating system work? If there is no air in the pipes, then the float is raised and the needle valve is in the closed position. When an air lock forms, the float drops, as a result of which the rocker arm opens the valve, air is released. When all the air is completely gone, the float returns to its original position, closing the valve.
How the manual fixture works
Manual air vents for heating systems (the price of which is lower than for automatic ones and starts from 200 rubles) have a simpler design, but the principle of operation remains the same. When the regulator turns, the valve opens, releasing accumulated air from the pipes. Rotation in back side brings the valve to the closed position.
If your apartment has an open heating system, then the air is released from it through expansion tank... Difficulties can arise if a pump is installed in the heating system that forcibly circulates water through the pipes. In this case, it is recommended to install a device for manual or automatic venting. But where to put the air vent in the heating system?
If you bought a manual device, then its installation should be done directly on the radiators. In this case, installation is recommended on all radiators, since it is in them that air is most often carried out. When using automatic devices the best place for the installation is the highest point in the heating system. This is due to the fact that the formed air will rise exactly upward, where it will be removed from the system through the air vent.
Structural performance
There are quite a few types of air vents, which differ from each other in their design.
They can be straight, angular, vertical or horizontal in shape. According to the principle of operation, this equipment is subdivided into ball and needle.
Some people who want to save money on heating in their home do not install air vents for heating systems, but ordinary taps. With their help, you can not only lower the air accumulated in the pipes, but also drain the stagnant water. But taps these days can be found very rarely, since most people prefer to install precisely air vents, which have already become an integral part of the heating system, which is not inferior in importance heating elements and radiators. It is the air vents that are responsible for maintaining the heating system in working order.
Installation of automatic devices
The efficiency of home heating and the reliability of operation depends on the correct installation of the drainage valves.
This work is not difficult, so everyone can cope with it, even if he has never done anything like this before. But here it is important to have an idea of \u200b\u200bthe installation procedure. So how is the installation of an automatic air vent in the heating system carried out?
As mentioned earlier, for their installation, you should choose those places in which the probability of airlock formation is the highest. These places include the highest points of heating equipment, collectors and heating circuits. There is one important nuance here: the air vents must be mounted strictly in a vertical position. If for some reason this is not possible, then you will have to purchase parts with a horizontal outlet.
So, we figured out how to properly install an air vent in a heating system with automatic descent. Let's now talk about how the manual diverter is installed.
Installing the handheld device
For old radiators used in central heating systems, installing automatic air vents will not be the best the best solution... This statement is true for at least two reasons. Firstly, such heating systems have been in operation for many years, during which they, as a rule, have never been cleaned.
Secondly, air locks are formed in them very often, therefore devices with automatic operation will wear out too quickly and fail. Thus, in apartments with old centralized heating, it is best to use manual devices.
How to install a heating system air vent with manual control? This is quite easy to do. First of all, a hole is drilled at the highest point of the radiator, in which a thread is then cut and a Mayevsky tap is screwed in. The whole process does not take much time and effort, so everyone can cope with it. It should be noted that the air vent should be installed on each radiator, where air locks are most often formed, which must be removed from the system.
When choosing manual air vents, pay attention to their markings. If they are in the heating system, then it is necessary to buy models MC-140 or OMES. They are able to withstand high temperatures, up to 150 degrees.
How to bleed air from the heating system?
We have already figured out the consequences that the formation of air jams in pipes and radiators can lead to, and also talked about how air vents are installed for heating systems. Now all that remains is to figure out how the air is released with the help of vents.
The first step is to inspect the heating system for leaks. If any are found, then you need to eliminate them. If the system uses forced circulation, it is necessary to check the serviceability of the water pump and take preventive measures. If everything is in order, then you can start bleeding.
This procedure is performed in the following sequence:
- Electricity is de-energized.
- The heater is switched off and the water supply to the heating system is shut off.
- The air vent opens to maximum, after which you will hear the characteristic hiss, which accompanies the release of air from the system.
- Stagnant water is drained until it runs clean and free of air bubbles.
After all the air has been released from the system, it must be filled with water. The first step is to fill the water heater, and only then the radiators and pipes. It will not be superfluous to add a special substance with anti-corrosion properties to the water. This will significantly increase the service life of the heating system and save on its partial or complete replacement.
If in the process of performing work you find that the heating system is clogged, then it is necessary to clean it. For this, it is better to use special chemicals that effectively deal with any blockages. You can buy them at any store specializing in the sale of heating equipment and related products.
