Airing the heating system circuits is a natural operational factor that cannot be completely ruled out. Gases are introduced into the pipeline and heater structures together with the coolant, which reduces the efficiency of the system, and in some cases can lead to breakdowns. To reduce such risks, an automatic air vent will help - this is a simple device that requires minimal maintenance effort, but at the same time performs a very important function.
Air vent design
The device is small and resembles the constituent elements of valves. The metal case is provided with a pipe for connection with the target equipment, and the working internal part is represented by a camera with a float and a valve. The standard inlet size of the automatic air vent is 1/2 inch, although 1/4 inch models are also found. This value should correspond to the length of the pipe or outlet of the equipment from which it is planned to release air.
To ensure the tightness of the device, a cover with a sealant and a plastic cap is also provided. In addition, the device of the automatic air vent of the heating system provides for a lever for pressure on the valve and a spring. The main materials for the manufacture of this design are metal and plastic. The body is made of brass, the spring and lever are made of stainless steel, and the remaining functional elements are made of polypropylene, nitrile and various composite alloys. This allows the device to withstand temperature loads up to 120 ° C at a pressure of about 10-15 bar. The average life of the brass mechanism is 30-40 years.
The principle of operation of an automatic air vent
In conditions of increasing temperature, air in a liquid medium begins to concentrate and rise upward. This process is especially noticeable with a decrease in pressure, when the solubility of gases decreases. Ultimately, air accumulates at the top of the system, which contributes to the formation of plugs. It is in these places that it is recommended to install devices for venting air. Previously, a Mayevsky crane was used for such purposes, but manual control made it unattractive - especially against the background of the appearance of an automatic air vent. The principle of operation of this device is based on the complete autonomy of the valves and float mechanism. When an air plug forms under the device, the float in the chamber begins to move upward. He presses on the rod, allowing access to the atmosphere through the device. In other words, the coolant gas outlet opens automatically through the exhaust valve system at the moment when sufficient force is generated under it from the pressure of the air plug.
Varieties of air vent
According to the structural device, the following types of automatic air vent can be distinguished:
- Straight. The most popular design that can be used for almost any heating equipment with a suitable input duct diameter. Most often, an automatic air valve with a straight pipe is placed at the highest point of the vertical riser. It is technically impossible to use manually operated valves in this area, and the simple design of an autonomous diverter in operation is just the optimal solution.
- Angular. Side models that are attached to equipment with a horizontal nozzle or pipes that run horizontally.
- Radiator. Special version of automatic air vent for water radiator heaters. Actually, the main feature of this device is not so much the structural design as the possibility of safe contact with aggressive liquid media in heating circuits. For example, some radiator models can be used in systems operating with low-freezing coolants.
Combination with shut-off valve
Before buying an air vent, you should consider one important operational nuance. On the connection pipe, the valve can be installed with or without a transitional protective link. This element is called a shut-off valve and serves as a kind of locking blocker that closes the circuit. That is, if it is necessary to remove the automatic air valve, then in a system with a shut-off unit, this can be done without blocking the water on the branch. The design of this element is designed so that when the outlet is connected, its valve automatically opens - and on the contrary, when the device is removed, the pipe closes. This device does not affect the deaeration process in any way, but it facilitates the dismantling of the air release system. In addition, the shut-off valve can be used as a phytin adapter when switching from one diameter to another, although this is not its main function.
Installation of an automatic air vent
Before installation, a comprehensive check of the device is performed. The housing must be free from dirt, rust and scale, if any. Next, you must perform the following steps:
- The most convenient area for placing an air vent is calculated. It is advisable to think it over at the design stage of the heating system. The mounting point should be as high as possible, should collect air and gases from all circuits and at the same time be accessible for maintenance.
- Using a shut-off channel or other connecting fittings (if necessary), screw the valve of the automatic air vent so that the sealing material ensures tightness of the joint. If an angle or radiator device is used, then the working part of the housing with the camera and the float must be turned upwards for unhindered air discharge.
- The air vent is drawn only with an open-end wrench - lever is not recommended.
- The tightness of the connection is checked, and then the cap in the upper part of the device housing is turned away. Next, you can fill the branch with coolant.
User's manual
An automatic air vent practically does not require human participation in the work process. The maximum that may be needed is tracking the correctness of its functioning. But how to bleed the battery if the device fails? In this case, it is necessary to control the process of bleeding gases from the heating circuit through the side plug. It is present in the simplest batteries, and the radiator panels are equipped with more modern mechanical valves. It is enough for the user to turn the valve or plug, after which the accumulated air will leave under the action of gravity.
When performing manual bleeding, it is important to consider several technical nuances. Firstly, at this moment the heating should be turned off - a boiler, boiler or other source of heating. Secondly, after bleeding when tightening the valve or plug, the valve must be sealed. How to bleed the battery without leaving a leak after that? At the junction, a sanitary fum tape or other sealant should be wound, which eliminates the possibility of maintaining gaps. The same is done in relation to the installation of automatic air vents, which also leak with a leak if they are not mounted correctly.
Air vent maintenance
Although the device has a rather simple design, the quality of its work will largely depend on the maintenance measures on the part of the owner. Depending on the place and application conditions of the air vent, its design may become clogged with dirt and dust, which will ultimately affect the work process. If foreign particles get into the circuit before it is filled with water, for example, then the likelihood of clogging of the valves will increase. Mechanical particles adversely affect the operation of equipment for heating systems; therefore, both the air vent and other valves providing entry to the piping line must be regularly cleaned.
A comprehensive check of the device with a revision of its design should be carried out before the heating season. For example, to save time and organizational resources, this measure should be combined with pressure testing (checking the pipeline for leaks). If a leak is detected in the nipple of the brass automatic air vent, the battery immediately closes, after which the water in the collector is drained. Heating equipment with pumps should be turned off by this moment and the channels with the coolant blocked to the location of the collector. After that, the air vent is removed, and the channel is cleaned with a plastic fishing line. Rinse the nipple with a 10% solution of oxalic or acetic acid.
Pros and cons of an automatic air vent
The main advantages of the device are its autonomy. It is an easy-to-use and effective solution for bleeding pipeline gases, which can be used both in private houses and in urban apartments - including on the upper floors. Compared with manual valves, the automatic air vent will benefit from a more aesthetic appearance, which does not spoil the design of a modern radiator. With regard to efficiency, as operating practice shows, the performance of batteries increases markedly - the difference depends on the nature of the airing of the heating circuits in a particular case.
When operating an automatic air vent, you will also have to face negative factors. These include the following:
- Since the process of air discharge will occur uncontrollably and continuously, not the most pleasant smell may be regularly present in the room. For comparison, one can prepare for a single volumetric discharge of gases from the batteries through the manual valve and after the operation ventilate the room once.
- Do not leave the device in working condition for a long time without supervision. This is a safety measure that prevents the risk of flooding.
- The organization of automatic air discharge from a heating system with hard and unfiltered water has its risks. They are associated with the sensitivity of the working filling in the chamber of the retractor. The same float with a locking system for regulating the process of bleeding in the valve with regular maintenance of low-quality coolant may fail.
How to choose an automatic air vent?
The selection begins with the type of structure, which is determined by the position of the outlet pipe of the target equipment. Further, operating parameters should be taken into account - including the temperature of the aqueous medium and pressure limits. Some models also have sensitivity limits in relation to the humidity coefficient - it is desirable that it does not exceed 80%. If we talk about manufacturers, then plumbers recommend focusing on Russian, Turkish and Italian brands. For example, quality products are supplied by VALTEC. Its model VT.501 has a wide range of operating parameters, is versatile and reliable. As a basic solution, the Danfoss Airvent Series automatic air vent can be considered. This version is suitable for pipelines, ventilation units, water collectors and air conditioners. The cost of this air vent is only 400 rubles. By the way, if it is necessary to comprehensively provide a large-scale heating system with several gas outlets, it is better to pre-purchase devices in sets for collector groups.
Conclusion
Devices for bleeding air from pipes are recommended to be used in all hydraulic systems that somehow work with plumbing infrastructure. This is not just a means of improving safety, but also an economically viable solution that maintains the heat output capacity at the proper level. What equipment for heating systems needs to be supplemented with an air vent? Theoretically, this could be batteries with radiators, and waste pipes from the pipeline line. The main thing is that it was just about the place of collection of the air plug, otherwise there will be little benefit from the valve. But in each case, in principle, is there a risk of excessive airing? As already mentioned, in different volumes of air is present in any heating network. You can talk about critical indicators when characteristic signs of airing are observed - small vibrations and noise of the pipeline. But in such situations, it is desirable to find out the causes of this phenomenon.