Types of air vents and their installation locations
Air vents are manual and automatic. Manual air vents or Mayevsky taps are small. They are usually installed on the end of the heating radiator. Mayevsky's crane is adjusted with a wrench, screwdriver or even manually. Since the tap is small, its performance is also small, so it is used only for local elimination of air locks in the heating system.
There are two types of air vents for the heating system: manual (Mayevsky tap) and automatic (work without human intervention).
The second type of air vents - automatic - work without human intervention. They are installed both vertically and horizontally. They have high performance, but they are quite sensitive to contaminants in the water, so they are mounted together with filters on both supply and return pipelines.
Automatic air vents are installed in closed-type heating systems along the pipeline line at different points. Then air is discharged from each group of devices separately. A multi-stage deaeration system is considered the most effective. With proper laying and proper installation of pipes (under the required slope), it will be easy and hassle-free to remove air through the air vents. The removal of air from heating pipes is associated with an increase in the flow rate of the coolant, as well as with an increase in pressure in them. A drop in water pressure indicates a violation of the tightness of the system, and temperature drops indicate the presence of air in the heating radiators.
What is dangerous air lock in the radiator
If there is air in the battery, nothing good will come of it. Excess air is an obstacle to the normal functioning of the system. And it can also cause corrosion on the walls of the radiator.
If a circulation pump is installed in the circuit. an air lock can disrupt its operation. When the system is functioning correctly, the plain bearings on the shaft of the pump unit are constantly in the water. And in the presence of air, the effect of "dry friction" occurs, which negatively affects the sliding rings, and can damage the shaft
Therefore, it is important to know how to expel air from the heating system at home. Measures taken in time will help prevent damage to the heating network
Air bleed through the plug
If there are no taps on the heating devices, such a problem as an air lock in the heating system of the house becomes much more complicated. You will need to unscrew one of the plugs.
For these purposes, you should prepare a large adjustable wrench. Place a container under the cap.
Next, the plug is captured with a key and rotated very carefully.
It is unacceptable to completely unscrew the plug, since there may be high pressure in the heating system, the coolant will go straight into the room with high pressure, and it will be problematic to cope with this situation
That is why the plug should be turned with extreme caution.
It is advisable to first turn off all available equipment in the room, close window and door openings tightly. In the process of turning the plug, you must listen
If a slight hiss appears, the plug should not be turned further.
At this point, you need to stop and put the key aside. Now you should wait until the excess air from the heater gradually but completely leaves the system. It is very simple to determine that the plug in the heating system has come out - liquid will begin to leak from under the plug.
Then, using a large adjustable wrench, it is necessary to smoothly and carefully return the plug to its original position.
Types of air vents
Valves for removal of air jams are automatic and manual. Mayevsky cranes belong to the second type of air vents. They are used not only to remove air, but also to start it in order to drain the coolant from the system.
Mayevsky crane
This device is made of brass, has a simple but reliable design. The main parts of the Mayevsky crane are the body and the screw. All parts of the valve are located as tightly as possible to each other, so that the coolant cannot escape. Open the tap with a special key, screwdriver or hand.
Before removing air from the heating system, it is necessary to prepare a container for the coolant and tools. Step-by-step instructions for removing air congestion using a Mayevsky crane:
- If the heating system is operated by means of a circulation pump, then it should be switched off for the time of air discharge.
- With a key, screwdriver or hand, the valve is turned 1 turn counterclockwise. Immediately, a hiss of air coming out of the radiator will be heard.
- As soon as the coolant began to flow out, it means that the air plug is removed, the Mayevsky tap is closed back.
Automatic air vent
Automatic air vent VALTEC VT.502
This device independently removes air from the heating system. Mounted either vertically or horizontally. Consisting of brass body, float, exhaust valve and articulated arm. To prevent the coolant from flowing through it, the air vent is equipped with a protective cap.
Note! Automatic devices are sensitive to impurities contained in water. For their long-term operation, cleaning filters are additionally installed in the heating system.
The principle of operation is as follows: if there is no air in the chamber, then the exhaust valve is closed. As it enters the float goes down. As soon as the chamber is completely filled, the outlet valve opens and the air is expelled to the outside. The float then closes the outlet valve again.
Air separator
This device consists of a metal case, an air vent, a drain cock and a tube with a mesh. Unlike conventional air vents, the separator itself takes air out of the water. Passing through the grid, the coolant swirls, due to which air bubbles are formed. As a result, they rise up, and the gases are removed through the air vent. In addition to air, the separator separates sand, rust and other impurities. The sludge is removed through a drain cock located on the outside at the bottom of the housing.
What are air vents and what are they for?
Many owners of radiator systems have encountered a situation where, with hot pipes, some parts of the radiator do not heat well or they are generally cold, similar problems arise with warming with water floors. The main reason for this phenomenon is the presence of air in the pipes, which rises and prevents the movement of the heat carrier.
If in an open circuit air bubbles are sent to an unclosed expansion tank located on high floors of a building or an attic, and bleed is not so important, then in a closed system an air vent of the heating system is vital on all circuits and individual heat exchangers.
When plugs interfere with the system, manual or automatic heating bleed valves are used to remove accumulated air. One of the simplest devices is a conventional valve installed at the top of heating radiators. To release air from the batteries, the valve is opened and they wait for the moment when the jet stops flowing jerkily along with air - in radiators without air, the water flow will be uniform.
In individual heating lines of private houses, instead of ordinary valves, special locks are installed on radiators, which operate automatically or are manually adjusted. With their help, not only air is removed from devices in which gas formation occurs, but also, when necessary, oxygen from water, which causes accelerated corrosion of metal fittings.
Rice. 2 Air vent for venting air from the heating system - design
Causes and consequences of air locks in a closed heating system with forced circulation
The reasons are the same as for an open system, plus:
- A loose impeller of the circulation pump can “grab” air during operation;
- If hot water is supplied to the expansion tank from above, then air can enter the system through cracks or ruptures in the tank membrane.
An air lock in a closed circuit will increase the pressure in the system and actuate the safety valve. The valve will bleed water over and over again until the boiler burns out or breaks the heating pipes. Therefore, the security requirements for closed systems are much stricter. In particular, for air release, a closed circuit is equipped not only with Mayevsky manual cranes, but also with automatic air vents. One of these automatic valves is included in the safety group. The group is placed on the water supply, immediately after the boiler.
Important! A leaky piping or radiator cannot cause an airlock. A working system, whether closed or open, is under pressure
Air will never go in the direction of higher pressure - this is contrary to all the laws of physics.
Air removal methods
There are heating systems with forced and natural circulation of the coolant. In the first case, the liquid flows with the help of a circulation pump, and in the second, due to a certain slope of the pipes and the pressure in them.
Natural circulation systems
An expansion tank is used to remove air from this type of system. It is installed at its highest point. Most of the air is independently discharged through it when the coolant is heated. If air pockets still remained, then many experts recommend increasing the amount of fluid in the system, while opening the air vents. Thus, the coolant itself will displace air from the network by movement and pressure.
Forced circulation systems
In systems with a circulating pump, pipes and radiators are located evenly and without slope. Air vents are used to remove air from them. They are always mounted at the bends and at its highest points, since it is there that the accumulation of gases occurs.
Note! If it is not possible to expel air from the system with the help of air vents, then it is necessary to drain all the coolant and refill it. It is necessary to fill the coolant into the system slowly, as air bubbles form due to rapid filling.
At the same time, it is necessary to remove air from radiators and other elements. The longer the system, the longer it is filled with coolant. If a warm floor is connected to the heating network, then the installation of air vents is mandatory, since pipes are often located at different heights. You also need to constantly monitor the amount of coolant in the system to exclude the possibility of air entering it.
It is necessary to fill the coolant into the system slowly, as air bubbles form due to rapid filling. At the same time, it is necessary to remove air from radiators and other elements. The longer the system, the longer it is filled with coolant. If a warm floor is connected to the heating network, then the installation of air vents is mandatory, since pipes are often located at different heights.You also need to constantly monitor the amount of coolant in the system to exclude the possibility of air entering it.
Why does air appear in the heating system
Many of our compatriots are familiar with the concept of "air congestion". This phenomenon is remembered at the beginning of the heating season, when heat is let into the houses, and in the apartments of the upper floors often the batteries do not heat up or heat up only in the lower part, and in the upper part they are absolutely cold. Where does air come from in pipes? There can be several reasons for airing:
- carrying out repair work (assembly, disassembly of the pipeline), during which the appearance of air is inevitable;
- non-observance during installation of the magnitude and direction of the slope of pipelines;
- low pressure in the water supply. the water level drops, and the resulting voids are filled with air;
- when water is heated, the air bubbles contained in it are released and rise to the upper part of the pipeline, creating air pockets there;
- the heating system is filled incorrectly: after a summer downtime, the pipes should be filled with water not quickly, but slowly, while simultaneously bleeding air from the heating system;
- unsatisfactorily sealed joints of pipelines through which the coolant leaks. The leak in these places is hardly noticeable, since hot water immediately evaporates. It is through loose seams that air is sucked into the system;
- malfunction of air intake devices;
- connection of a water "warm floor" to the heating system, the pipes of which are located at different heights during installation.
Heating air vent
Design, principle of operation of the air vent
But in addition to radiators, situations often arise when it is necessary to expel an air lock from the heating system in the pipes. To do this, it is necessary to install air vents in certain sections of the highway. Their design is in many ways similar to the described Mayevsky automatic cranes. However, there are significant differences - they are designed for the largest volume of exhaust air and are not installed horizontally, but vertically.
In order to remove the resulting air lock from the heating system, you first need to install air vents in the right places:
- At the highest point on the highway. For an open system, this is only possible if a sealed expansion tank is installed on the return pipe;
- In collector heating - on each comb;
- For tee wiring - in front of each trunk branching node.
After installation, it is necessary to correctly set the pressure value at which the air vent will work. To remove an airlock from the heating system, a coolant is injected into the pipes until the air vent on the return line works.
Removing the air lock in autonomous heating, you need to reduce the temperature of the coolant to a minimum. This will reduce the volume of water and help you troubleshoot more effectively.
In combination with the functional qualities of Mayevsky taps, this makes it possible to effectively break through any plug in the heating
It is important that the response parameters of the devices do not exceed the critical pressure value. Otherwise, the security of the system may be compromised.
The video shows an example of airing a heating radiator:
Why are there taps on radiators?
Each heater is a separate element of the system that needs adjustment and periodic maintenance. If, however, the flow of coolant through the batteries is controlled depending on the need for heat, then good results can be achieved in terms of energy savings. That is, radiator valves and taps for heating are designed to solve such problems:
- Complete isolation of the heating device from the system.
- Restriction of the coolant flow through the battery.
- Change in coolant flow depending on external conditions.
- Bleeding air from the radiator and piping network.
There are many situations in which it is difficult to do without disconnecting the battery. For example, a properly functioning central heating in the middle of spring, when it is already warm outside, and the apartment is just hot. Another case is the need to remove the heater in order to replace, flush or repair. In the absence of shut-off valves, it becomes problematic to carry out any action with the radiator.
Valves put on batteries in retro style
Restriction of the flowing coolant is carried out in order to balance individual heating in a private house or apartment
No matter what type of heating system you have, without balancing with valves, the first batteries will always receive more water than the last ones. To limit the coolant flow at the beginning of the network and thereby equalize all the devices with each other is the task of the control radiator fittings
Automatic control of the flow of the incoming coolant is a way to save energy used to heat the house. If each faucet on the heating battery maintains the set air temperature in the room, controlling the flow of water through the radiator, then in general the system will consume only the required amount of heat, no more. And that's a big savings.
Well, the problem of air release when filling the system or during operation is also solved by special air valves installed on all modern radiators. Below is a list of varieties of shut-off and control valves, listed in the same order as the tasks it solves:
- Semi-turn ball valves in straight and angle versions. They are made of brass, bronze or polypropylene with a metal insert.
- Balancing valves for radiators - straight and angled.
- Adjusting valves with thermal heads (thermostatic valves).
- Drain valves - automatic and manual.
For reference. Some home craftsmen use three-way mixing valves to connect heaters. But such a solution is unreasonably expensive and rarely used in practice.
Now we should consider in detail which taps are best placed on radiators in various conditions and circumstances. Some options are clearly shown in the video:
Automatic air vent valve from the heating system
A fluid heating system uses a number of specialized components to ensure its reliability and efficiency. These include an air valve (separator) for heating. A device for venting air from a heating system makes it possible to remove gases accumulated in the pipeline and radiators.
When an air lock forms in the pipeline, it tends to the highest point of the radiator or the heating circuit as a whole. If an automatic air release valve is installed in this place, the coolant from its inner chamber is displaced by gases.
When the liquid is displaced, the float goes down and opens the valve, as a result of which gases are bled from the heating pipeline, and the chamber is again filled with coolant.
The valve for automatically venting air from the heating system becomes silted over time, overgrown with scale. This leads to jamming of the mechanism, loss of tightness of the valve - moisture begins to seep through it. Such a device requires replacement - automatic air vents cannot be repaired.
The number of automatic air vents depends on the characteristics of the heating system.
- Device required for installation:
- as part of the safety group of the boiler unit at the outlet pipe of the water jacket, where the coolant is heated to the maximum temperature;
- at the highest point of the vertical risers - it is there that gaseous substances rise and accumulate;
- on the distribution manifolds of underfloor heating, so that air can be bled from the circuits;
- on U-shaped loops made of polymer pipes, which are equipped to compensate for the thermal expansion of the pipeline.
Selection principles
Air valves for the heating system can be part of a safety group or a collector kit for underfloor heating, supplied with heating devices.
The air vent is selected taking into account its operating parameters (maximum allowable temperature and pressure), they must correspond to the characteristics of the heating system. By execution, they are divided into straight and corner devices, horizontal and vertical.
- Mayevsky cranes differ in the way the working screw is unscrewed:
- with a stem head for a special key (the inconvenience is that the key may not be at hand at the right time);
- with a non-removable handle (cannot be used in places accessible to young children to eliminate the risk of burns from heated coolant;
- with a slot for a flat screwdriver (the most convenient and safe option).
In order to equip the heating system with a reliable air release valve, it is recommended to choose products of well-known brands. Cheap products made of brittle silumin imitating brass should be avoided.
What is dangerous air in the heating system
The air dissolved in the coolant gradually disables steel pipes and radiators, elements of the boiler unit. The corrosive activity of air, which was first dissolved in water and then released during heating, significantly exceeds that of atmospheric air due to the increased oxygen content.
The gases accumulated in the pipeline not only provoke or accelerate the corrosion of metal elements, but also form air pockets that prevent the heating system from fully functioning:
Due to gas plugs, the circulation of the coolant worsens; in serious cases, the movement of fluid through the pipes can be completely blocked. In such a situation, the heating devices cool down quickly.
Air locks work as a heat insulator, and if gases have accumulated in the upper part of the battery, it warms up worse and gives off less thermal energy to the room.
In the presence of air pockets, the movement of the coolant along the heating circuit is accompanied by loud gurgling sounds and murmuring, which violates the acoustic comfort in the house.
Circulation pumps are not designed for pumping gases; when working with air coolant, the bearing and impeller of the pump unit wear out much faster.
Special air vents allow you to solve the problems associated with airing the heating system
It is important to choose the right valves for bleeding air and correctly determine the location of these elements.
https://youtube.com/watch?v=Q4LOLnuFOoc
balancing valve
The valve for adjusting heating differs in design from a conventional ball valve in that it can smoothly close the flow area in a few turns. Moreover, after balancing, the position of the valve can be fixed so that no one accidentally violates the settings. This type of control valves is placed at the outlet of the radiator, as shown in the diagram:
Shown here is the connection to a two-pipe horizontal system, the most common in private houses and apartments with individual heating. By the way, the principle of mounting fittings with a single-pipe scheme remains the same. An ordinary ball valve is placed on the supply line, and an adjusting valve is placed on the return line.In the case when a system with vertical risers takes place in a two-story house, then the installation diagram of the associated fittings looks like this:
The principle of product selection is the same as in the previous section.
Direct or angular execution is accepted depending on the layout of equipment and pipelines, it is also important to use American women when assembling
Pay special attention to the quality of the casting and the thickness of the brass walls of the reinforcement. If you have networks of polypropylene pipes, do not rush to buy PPR taps, it is better to put adapters and reliable metal products
Advice. Balancing valves are placed on all radiators, except for the last one, which is at the dead end of the branch. On the connections to it, it is enough to put simple ball valves.
How to remove an air lock
Ideally, gases rise to the highest points of the circuit, where air vents are installed, and are vented from there by valves operating in manual or automatic mode. In practice, errors in the design or installation of the pipeline lead to the formation of air pockets in hard-to-reach places.
To remove such a plug, you need to find its location - by the murmur of the coolant flowing through the airy section, by the relatively low temperature of the pipe or radiator, by the ringing sound when pipes are tapped.
An increase in the temperature of the coolant and / or pressure in the system will help to expel the plug from the autonomous heating system. To apply pressure, it is necessary to open the make-up valve and the drain valve closest to the air lock (in the direction of flow). The water entering the system increases the pressure and forces the plug to advance. After making sure that the plug has exited through the valve (it stops hissing), the system is returned to normal operating mode.
Removing an airlock from the heating system
In more complex cases, not only pressure is applied, but also temperature. The coolant must not be heated above the maximum allowable values, so as not to disable the heating system.
Important! The regular formation of a cork in the same place indicates miscalculations in the project or incorrect installation. It is recommended to install an air vent in a problematic place by cutting a tee into the pipeline
