How to select and install an air valve for heating. Application of air vents for heating systems Automatic air vent operating principle

Content

1. Air in the heating system - why is it bad?
2. Design and principle of operation of an automatic air vent
3. Types and markings, popular models
4. Installation in a heating system

Introduction

The presence of air in the heating system is extremely undesirable. However, he gets there one way or another. This has a very detrimental effect on the quality of operation of the heating system as a whole and reduces the service life of its individual components. In order to remove accumulated air, an automatic air vent is needed.

In this article we will talk in detail about this device, the principle of its operation, marking features and popular models, as well as how to properly install it in the heating system.

Air in the heating system - why is it bad?

It would seem that the heating system is closed, completely filled with coolant, where does the air come from? There are several ways for it to appear inside, among them there are several main ones:

• While filling with coolant

  While you fill the heating system with water or other coolant, it mixes with air. It is almost impossible to avoid this, so you have to take it for granted.

• Through poor connections

  Poor installation of a heating system or other heating device, poor quality, defective or broken shut-off valves or other elements - all this leads to air penetration inside.

• Chemical reactions

  In addition to air, other gases can accumulate inside. For example, if you use a coolant with high acidity and aluminum radiators, hydrogen will be released as a result of a chemical reaction.

Photo 1: Automatic air vent for heating systems

As you can see, there are many reasons for this phenomenon. But why is this so bad? The first thing this leads to is cavitation. It significantly accelerates the wear of equipment and leads to noise during its operation. The second reason is corrosion. It destroys the elements of the heating system and carries their particles with the coolant flow to other devices, clogging and interfering with their normal functioning. Thirdly, the presence of air reduces the actual heat transfer of heating devices and leads to disruption of the pumps. It can even cause a rupture of the boiler casing.

To eliminate all these problems, an automatic air vent is used. Let's figure out how it works in the heating system and what components it consists of.

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Design and principle of operation of an automatic air vent

The design of this small device is very simple. Inside the brass body there is a polypropylene float which is connected via a rocker arm to the spool. As the body fills with air, the float moves down and opens the exhaust valve. The freed space is filled with water and the rising float closes the spool. To prevent various debris, dust and dirt, from getting inside the spool, its outlet hole is closed with a plastic cap.

Photo 2: Design of an automatic float-type air vent

There are models with a slightly different implementation of this process, but in general it is always the same: when the float is down, the valve is open and releases air; if it is raised, the spool closes and the device accumulates gas again. This cycle is repeated again and again automatically.

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Types and markings, popular models

There are several types of automatic air vents. All of them are divided into two large types: automatic and.

Depending on the diameter of the threaded connection, they are of two types: 1/2 and 3/4 inches. The first is better known by Russian markings as an automatic air vent valve Du 15, the second - Du 20.

According to the method of fastening, they are divided into classic straight and lateral. For air vents of the second type, the threaded connection is rotated 90 degrees. The air release valve may also be located on the top or side. Various modifications are produced by the manufacturer to facilitate installation in difficult places in the heating system or for mounting on the side of radiators.

Photo 3: Automatic air vent DN15 “Valtec” VT 502 with shut-off valve

Two manufacturers are best known on the domestic market: Valtec and Danfoss. The Valtec company supplies the Russian market with an automatic air vent VT.502 with a mounting diameter of 1/2 (DN15). The model has proven itself well and is very popular among installers of autonomous heating systems in private homes. It has a brass body coated with a layer of nickel, which is designed for a maximum pressure of 10 bar and a temperature of 110 °C. The average price at which you can currently buy this model is 280 rubles.

Photo 4: Automatic air vents 1/2 "Danfoss" series "Eagle" and "Wind"

Danfoss takes second place. It produces automatic air vents in two series: “Eagle” and “Wind”. Despite the general technical characteristics, they differ only slightly in appearance. The models are made in brass cases and are designed for a maximum pressure of 10 bar and a temperature of 120 °C. In addition to the standard mounting thread DN15 (1/2), Danfoss also produces automatic air vents with fastening 3/8 (DN10). Prices for these devices are also within 300 rubles.

The main problem of living in city apartments is the heating system. Heating is a rather complicated scheme for heating various industrial buildings and residential premises, which is based on regularly maintaining a microclimate that is comfortable for living.

Before the start of the heating season, utility services warn every year that the air needs to be vented. In some cases, the cause of air is the release of hydrogen from water due to peculiar chemical effects. But this problem can be avoided if you install 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 initially filling the system with water;
• due to poor quality or worn sealing elements;
• due to water recharge;
• corrosion inside pipes;
• violation of installation rules during installation and system, etc.

When water enters the heating system, it contains a large amount of oxygen, which expands when heated and forms air pockets. They, in turn, reduce the pressure in the system and reduce the rate of water circulation. Thus, if your apartment does not have air vents installed for heating systems, then you must manually bleed the air. If this is not done, the room will heat up poorly and unevenly, which, in turn, will negatively affect the comfort of living.

Kinds

There are two types of air vents:

• manual;
• automatic.

Heating systems are more practical and convenient to use, since they do not require any human action. However, their cost will be higher than their manual counterparts. Their installation should be carried out in places where the likelihood of air pockets is highest. Installation of manual ones is carried out on heating radiators.

How do they work?

The operating principle of an air vent in a heating system depends on the design features of these devices.

Manual air vents (as the name suggests) require human intervention, while automatic equipment can simply be installed and forgotten about forever, since it will bleed air on its own as the need arises.

What problems can air in the heating system cause?

Before we talk about how to install an air vent in a heating system, let's first understand the main problems that can result from the appearance of air in heating pipes and radiators. The air impedes the circulation of water through the system, as a result of which the efficiency of heating 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 places where individual elements are welded.

The accumulation of air in the pipes will contribute to their rusting and reduced service life. But the worst problem is defrosting the system, which can leave you without heat in the winter.

Design features

Manual and automatic air vents have similar design features, with the exception of 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 what type of equipment to install in your home, you need to understand the operating principle of a manual and automatic air vent.

How does an automatic control device work?

So, how does an air vent work in a controlled heating system? If there is no air in the pipes, the float is raised and the needle valve is in the closed position. When an air lock forms, the float lowers, as a result of which the rocker arm opens the valve and air is released. When all the air is completely released, the float returns to its original position, closing the valve.

Operating principle of the handheld device

Manual air vents for heating systems (the price of which is lower than automatic ones and starts from 200 rubles) have a simpler design, but the operating principle remains the same. When the regulator rotates, the valve opens, releasing accumulated air from the pipes. Rotation in the opposite direction brings the valve to the closed position.

If your apartment has an open heating system, then air is vented from it through the expansion tank. Difficulties may arise if the heating system has a pump that forcibly circulates water through the pipes. In this case, it is recommended to install a device for manual or automatic air release. But where to install the air vent in the heating system?

If you bought a manual device, then it should be installed directly on the radiators. At the same time, installation is recommended on all radiators, since it is in them that airing most often occurs. When using automatic appliances, the best installation location is the highest point in the heating system. This is due to the fact that the resulting air will rise upward, where it will be removed from the system through the air vent.

Design

There are quite a few types of air vents, which differ in their design.

They can be straight, angular, vertical or horizontal in shape. Based on the principle of operation, this equipment is divided into ball and needle.

Some people who want to save money when heating their homes do not install air vents for heating systems, but install regular taps. With their help, you can not only release the air accumulated in the pipes, but also drain stagnant water. But taps can be found very rarely these days, since most people prefer to install air vents, which have already become an integral part of the heating system, which in its importance is not inferior to heating elements and radiators. It is the air vents that are responsible for maintaining the heating system in working condition.

Installation of automatic devices

The efficiency of home heating and operational reliability depend on the correct installation of diverters.

This work is not difficult, so anyone can cope with it, even if they have never done anything like this before. But here it is important to have an idea of ​​the installation procedure. So how is an automatic air vent installed in a heating system?

As mentioned earlier, for their installation you should choose those places where the likelihood of air pockets is the highest. These places include the highest points of heating equipment, collectors and heating system circuits. There is one important nuance here: air vents must be mounted strictly in a vertical position. If for some reason this is not possible, then you will have to purchase additional parts with a horizontal outlet.

So, we figured out how to properly install an air vent in a heating system with automatic drainage. Let's now talk about how to install a manual lifter.

Installation of the handheld device

For old radiators used in central heating systems, installing automatic air vents will not be 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 pockets form in them very often, so 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 manual heating system air vent? 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 the Mayevsky tap is screwed in. The whole process does not take much time and effort, so anyone can handle it. It is worth noting that an air vent should be installed on each radiator, where air pockets most often form, which must be removed from the system.

When choosing manual air vents, pay attention to their markings. If there are any in the heating system, then you need to buy the MS-140 or OMES models. They are able to withstand high temperatures, up to 150 degrees.

How to bleed air from the heating system?

We have already dealt with the consequences that the formation of air locks in pipes and radiators can lead to, and we also talked about how air vents for heating systems are installed. Now all that remains is to figure out how the air is released using vents.

The first step is to inspect the heating system for leaks. If any are found, they need to be eliminated. 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 the air.

This procedure is performed in the following sequence:

1. Electricity is cut off.
2. The heating device is switched off and the water supply to the heating system is cut off.
3. The air vent opens to the maximum, after which you will hear a characteristic hissing sound, which is accompanied by the release of air from the system.
4. Stagnant water is drained until it comes out clean and free of air bubbles.

After all the air has been released from the system, it is necessary to fill it with water. The water heater is filled first, and only then the radiators and pipes. It would be a good idea to add a special substance to the water that has anti-corrosion properties. This will significantly increase the service life of the heating system and save on its partial or complete replacement.

If during the work you find that the heating system is clogged, then it is necessary to clean it. To do this, it is better to use special chemicals that effectively deal with any blockages. You can purchase them at any store that specializes in selling related products.

Although it belongs to the category of auxiliary equipment for the heating system, this does not mean that it is completely unnecessary. Yes, in systems with natural coolant circulation, in which there is an open expansion tank, an air vent is useless. But in closed systems... there’s really no point.

Why do you need an automatic air vent?

The purpose of this device speaks for itself: to remove air from the heating system, and in automatic mode, without our participation.

The appearance of the air vent is as follows:

This is with a bronze body. And this is with a stainless steel case:

In the second photo, in addition to the air vent, there is also a shut-off valve; these two devices are often placed together.

Why is there a shut-off valve for an automatic air vent?

For convenience: first screw in such a valve, and then install an air vent into it; the valve has a plastic flag, which, when screwed in, the air vent presses on, thereby opening access to the heating system. If for some reason you need to disconnect the air vent, you do this, after which the valve will cover the remaining “hole”, preventing the coolant from leaking out. We repaired this air vent or bought a new one, screwed it in again - the valve opened...

How does an automatic air vent work?

The automatic air vent device can be seen in the following diagram:

It works like this. Air enters the air vent, opens the valve, through which it is released from the system. When the air has escaped, water enters the cavity under the float (3) - the float floats up, acting on the rod and closing the valve.

The following diagram shows an air vent of a different model, but they all work on the same principle:

How to repair an automatic air vent?

What problems can occur with automatic air vents?

Above the door - when the pipeline goes around the doorway:

(it happens, however, that the air vent starts to leak, and so does the appearance... but sometimes it doesn’t work out any other way)

If there is a hydraulic arrow in the system, on its body:

Attention! Before starting the heating system, you need to slightly open the cap on top of the air vent.

That's probably all I can tell you about the automatic air vent. I hope you had the patience to read this far? Then see you in the next articles.

automatic air vent

An automatic air vent in heating systems is a device that helps get rid of excess air. As a rule, it is made of bronze or stainless steel.

What does the device consist of?

An automatic air vent consists of a housing with a connecting size that is no more than 15-16 mm. This device can be easily screwed onto a radiator at the required location in the overall room heating system. You can also screw in the air vent together with the shut-off valve.

The automatic shut-off valve is screwed directly onto the radiator into the heating system, and the air vent itself is mounted on top of it, which as a result should press a special plastic flag and open access to the entire heating system.

An automatic valve is needed so that you can easily dismantle or replace the air vent in the event of a breakdown. When the air vent is unscrewed, the flag rises up. An internal spring cuts off the area where the leak occurred. If you screw on a new air vent, the valve will open again and the entire system will work.

Let's take a look at the diagram and understand the operating principle of automatic air vents. The coolant is installed directly into the cavity in which the plastic float is located. Due to a special flag, it creates pressure on the spring-loaded rod. As a result, access to the external environment is opened.

According to this scheme, the air leaves the heating system. If water fills the entire cavity, the float will begin to press on the rod and close the hole, and at the same time the air access. This operating principle applies to absolutely all air vents.

Air vent malfunctions

Heating depends on the quality of all elements. If the coolant is of poor quality, the needle begins to coke. As a result, substances are formed on it, which dissociate in water into metal cations and anions of acid residues. Due to the salts, the needle does not close completely and begins to leak.

In this case, it is advisable to unscrew the cap and thoroughly clean the needle from dirt. Don't forget to remove dirt from the rocker mechanisms. After cleaning all elements of the air vent, as a rule, the leakage stops.

Another problem that often occurs with air vents is the destruction of the sealing rings under the cover. With such a breakdown, coolant leakage is noticeable. If you notice that the O-rings have become unusable, it is better to replace them or wrap FUM tape on the threads of the device.

If the O-rings have become unusable, you can wind FUM tape onto the threads of the device

Types of car air vents

All air vents are usually divided into several groups:

1. Direct.
2. Angular.
3. Radiator.

The latter are convenient to use if your heating (the entire system) is not designed rationally, and you notice that air often accumulates in it.

Recently, the Mayevsky crane has become very popular, although these devices are not automatic. It is customary to install the Mayevsky tap directly on the radiator. This faucet is very convenient to bleed off excess air - just slightly open the screw with a screwdriver.

Do not forget that in order to effectively remove air, you need to make a certain slope when installing the radiator. It must be made in such a way that the part with the Mayevsky tap is slightly higher.

In conclusion, we note that without air vents it is difficult to ensure high-quality heating. Don't forget that installing these devices is a complex process. They must be mounted at the highest points in the heating system.

This is due to the fact that air accumulation and the formation of air jams are most likely there. Also, do not forget that the nipple must point straight up, otherwise the air vent float will not work correctly and the heating will “go away.”

Air in the heating system is not even bad, it is critical and negatively affects the heating efficiency of the house. And the most unpleasant thing about it is that it constantly forms in the pipes. Therefore, its removal is a never-ending process. That is, a person has to either constantly release it manually using a Mayevsky crane, or automatically, which is much more attractive. It is for this purpose that a device such as an automatic air vent was created, which is the topic of this article - together with the site, we will understand its design, get acquainted with the varieties and principle of operation, and also talk about how and where it is installed.

Automatic air vents in the heating system photo

Automatic air vent: operating principle

You will probably be very surprised if I say that Mayevsky’s automatic crane works on almost the same principle as - in both devices, the main work is performed by the float. In the case of a toilet, the movement of the float closes and opens the needle valve through which the liquid passes, and in the case of an automatic vent, gas is removed through the needle valve. In fact, in such a system there are only two operating positions of the valve - float at the top and float at the bottom.

Everything is fine, everything works, and the air is removed automatically - there is no need to manually control this process anymore. There is really one “but” - this whole system only works when the float is in a vertical position, that is, the automatic air valve itself, which is not always possible to achieve in a 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 - varieties, so to speak.

Types of automatic air vents

There are three types of these devices in total - 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 are used to open and close it - the only difference is in the position of the body relative to the connecting pipe, i.e. threaded connection.

1. Direct automatic air valve for heating. The most common device for automatic air removal. It is intended only for vertical installation - in the sense that if you suddenly decide to use it for a battery, you will additionally need a 90-degree angle. The optimal area of ​​their application is pipelines, or rather their upper points, where, according to all the laws of physics, the air generated in the heating rushes. If it were not for such devices, it would be very inconvenient to vent air at the highest points of heating systems. In addition, some heating system equipment is also equipped with automatic vents with direct connecting pipes. For example, an automatic air valve is an integral element, which also includes a pressure gauge and an explosion valve. Other equipment is also equipped with air vents, at the top of which there is a possibility of air accumulations.

   

   Automatic air valve photo

2. Corner air vent. In short, corner air machines are used where it is not possible to install its direct counterpart - it may either not fit in the right place, or the equipment may have a side outlet with a thread. In general, there are many different situations, and it makes no sense to list them all, especially since the essence and principle of operation remain unchanged - only the location of the threaded outlet connection pipe changes and, as a result, the appearance of the automatic. A very important condition for the proper functioning of the corner air vent machine is the strictly vertical installation of its body. Horizontally and even at a slight angle, the machine will not be able to operate adequately - the float will get stuck and, as a result, air removal will be untimely or will not be removed at all.
3. Automatic air vent for . In essence, this is a type of angular machine for removing air, although you can’t tell from the outside - all these nuances are hidden inside the case. The outer part of the battery vent is created based on aesthetic considerations. In addition, these devices also differ in the diameter of the connecting pipe - on modern radiators they are installed directly into the battery, without the use of foot nuts. On old batteries they are mounted through a fitting with a threaded hole through it, and for steel convectors special machines with a half-inch pipe are used.

   

   Automatic air vent for radiators photo

These are all the varieties that the automatic air valve for. In principle, you don’t need more, since regardless of the different installation conditions, one of them will still work.

Which is better: automatic or manual Mayevsky crane

No matter how attractive the operation of an automatic air release valve may look, no matter what advantages it promises, there are still some circumstances that do not speak in its favor. Or at least talking about the economic inexpediency of installing an automatic machine. Such circumstances are rare, but nevertheless they occur.

Why such distinctions, you ask? Everything is quite simple - an automatic air vent costs at least 10 times more than a Mayevsky faucet. So if there is no special need for 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 valve - you just need to press a match or something else thin on its internal pin, and the air will come out. Alternatively, if you don’t have it, some water will do.