Airing the circuits of the heating system is a natural operational factor that cannot be completely eliminated. Gases are brought into the pipeline and heater structures along with the coolant, which reduces the efficiency of the system, and in some cases can lead to breakdowns. An automatic air vent will help reduce such risks - this is a simple device that requires minimal maintenance, but at the same time performs a very responsible function.
Design of the air vent
The device is small and resembles the components of valves. The metal case is provided with a branch pipe for connection with the target equipment, and the working inner part is represented by a chamber with a float and a valve. The standard size of the automatic air vent inlet is 1/2inches, although 1/4-inch models are also found. This value will have to correspond to the piece of pipe or outlet pipe of the equipment from which it is planned to release air.
To ensure the tightness of the device, a cover with a seal and a polyethylene cap is also provided. In addition, the device of the automatic air vent of the heating system provides for the presence of 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 rest of the 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 service life of a brass movement is 30-40 years.
The principle of the automatic air vent
As the temperature rises, the air in the liquid medium begins to concentrate and rise up. This process is especially noticeable when the pressure decreases, when the solubility of gases decreases. Ultimately, air accumulates at the upper points of the system, which contributes to the formation of traffic jams. It is in these places that it is recommended to install devices for air discharge. Previously, a Mayevsky crane was used for such purposes, but manual control made it unattractive - especially against the backdrop of the appearance of an automatic air vent. The principle of operation of this deviceis based on the complete autonomy of the valves and the float mechanism. When an air lock is formed under the device, the float in the chamber begins its upward movement. It presses on the stem, opening access to the atmosphere through the device. In other words, the outlet for the release of coolant gases opens automatically through the vent valve system at the moment when sufficient force is formed 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 inlet diameter. Most often, an automatic air valve with a straight pipe is placed at the highest point of a vertical riser. It is technically impossible to use manually operated valves in this area, and the simple design of a self-contained trap is just the best solution.
- Angular. Side models that attach to equipment with a horizontal nozzle or pipes that run horizontally.
- Radiator. Special version of the automatic air vent for water radiator heaters. Actually, the main feature of this device is not so much the design, but the possibility of safe contact with aggressive liquid media in heating circuits. For example,some radiator models can be used in systems working with low-freezing coolants.
Combination with shut-off valve
Before buying an air vent, one important operational nuance should be considered. On the branch pipe of the connection, 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 shut-off 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 block, this can be done without shutting off the water on the branch. The design of this element is designed so that when the trap is connected, its valve automatically opens - and vice versa, 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 descent system. In addition, the shut-off valve can be used as a fitting adapter when changing from one diameter to another, although this is not its main function.
Installation of automatic air vent
Comprehensive testing of the device is performed before installation. The housing must be free from dirt, rust and scale, if any. Next, you need to do the following:
- The most convenient area for placing the air vent is calculated. It is advisable to think it over at the design stage of the heating system. Mounting point should be as high as possible, should collect airand gases from all circuits and still be accessible for maintenance.
- Using a shut-off channel or other connection fittings (if necessary), screw in the automatic air vent valve so that the sealing material ensures the tightness of the joint. If a corner or radiator device is used, then the working part of the body with the chamber and the float must be turned upwards for unhindered air release.
- The air vent is tightened only with an open-end wrench - it is undesirable to use lever wrenches.
- The tightness of the connection is checked, after which the cap is turned off in the upper part of the device case. Then you can fill the branch with coolant.
Operating instructions
Automatic air vent practically does not require human intervention in the process. The maximum that may be needed is to monitor the correctness of its functioning. But how to bleed the battery if the device is out of order? In this case, it will be necessary to control the process of bleeding gases from the heating circuit through the side plug. It is present in the simplest batteries, and radiator panels are equipped with more modern mechanical valves. The user only needs to turn the valve or plug, after which the accumulated air will leave by gravity.
When performing a manual bleed, there are a few technical considerations to keep in mind. First, at this point it should be turned offheating - boiler, boiler or other source of heating. Secondly, already after bleeding, when tightening the valve or plug, the valve must be sealed. How to bleed the air from the battery without leaving a leak after that? At the junction, plumbing fum tape or other sealant should be wound, which will eliminate the possibility of maintaining gaps. The same is done with regard to the installation of automatic air vents, which also suffer from leaks if they are not mounted correctly.
Air vent maintenance
Although the device has a fairly 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 conditions of use of the air vent, its design can become clogged with dirt and dust, which will ultimately affect the work process. If foreign particles enter 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 heating equipment, so both the air vent and other valves that provide entry to the pipeline must be cleaned regularly.
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 tightness). If in the nipple of the brass automaticIf the air vent valve detects a leak, the battery is immediately shut off, after which the water in the collector is drained. Heating equipment with pumps by this time should be turned off 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. It will not be superfluous to 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 efficient solution for venting pipeline gases, which can be used in both private houses and city apartments - including on the upper floors. Compared to manual valves, an automatic air vent will also benefit from a more aesthetic appearance that does not spoil the design of a modern radiator. As for efficiency, as operation practice shows, battery performance is noticeably increased - 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 constantly, not the most pleasant smell may regularly be present in the room. For comparison, one can prepare for a one-time volumetric discharge of gases from batteries through a manual valveand ventilate the room once after the operation.
- Do not leave the device in operation for a long time without supervision. This is a safety measure that prevents the risk of flooding.
- Organization of automatic discharge of air from a heating system with hard and unfiltered water has its own risks. They are connected with the sensitivity of the working filling in the trap chamber. The same float with a shut-off system for regulating the bleeding process in the valve with regular maintenance of low-quality coolant can fail.
How to choose an automatic air vent?
It is worth starting the selection with the type of construction, 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 aquatic environment and the 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. The Danfoss Airvent series automatic air vent can be considered as a basic solution. 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 withmultiple gas outlets, it is better to pre-purchase devices in manifold kits.
Conclusion
Device for bleeding air from pipes is recommended for use in all hydraulic systems that somehow work with plumbing infrastructure. This is not just a means of increasing safety, but also an economically viable solution that maintains the heat output at the proper level. What equipment for heating systems should be supplemented with an air vent? Theoretically, these can be batteries with radiators, and waste pipes from the pipeline. The main thing is that we are talking about the place where the air plug is collected, otherwise there will be little use from the valve. But is there a risk of over-airing in every case? As already mentioned, air is present in different volumes in any heating network. We 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 reasons for this phenomenon.
