The effectiveness of heating depends on a combination of several factors. But even with a powerful boiler, good radiators and well-organized communication, the efficiency of the entire system can be reduced. The reason for this is the air that appears in the pipes. It creates air jams and interferes with the circulation of the coolant. All this, in turn, leads to an excessive consumption of fuel. Therefore, all closed- type heating systems are equipped with so-called air valves.
How air appears in the heating system
Both open and closed heating systems are subject to the process of air formation inside. This is inevitable, and the reasons for this are as follows:
- The release of air from the water. The standard air content in water is over 30 grams per ton. Under the influence of temperature processes, part of this air is released into a free state.
- Leaks in the system. If the heating is leaking, then you constantly have to replenish it with water, creating the necessary pressure. The pump also supplies air bubbles with water, as a cavitation process occurs.
- Miscalculations in the design of heating, leading to boiling of the system or cavitation processes at the suction inlet of the circulation pump. Improper slope prevents air from advancing to the air outlets. Lack of sufficient air valves or improper installation.
Also, during the initial injection of water into the hollow pipes, the air in the heating system may not be completely removed.
In addition to the fact that air interferes with heat transfer, the oxygen contained in it contributes to the corrosion process of metal parts of the system.
Air valve: what is it
A plumbing device designed to remove air formations from a closed heating system by diverting them to the outside is called an air vent, or, scientifically, an air valve. There are two types: air valve for manual heating and automatic.
Such devices are installed in places of alleged air accumulation to prevent the formation of air jams. All heating radiators are equipped with air ducts, and each circuit line must have an automatic air vent for heating.
For greater efficiency, air vent valves are installed with an air trap system. Plungers are made of materials resistant to corrosion and the formation of salt deposits. And they work at elevated pressure and temperature.
Air valve device for heating system
The standard vent valve has:
- A housing that is screwed to a rubber gasket at a specific point in the heating system.
- Exhaust valve. An element that works in automatic mode or is driven by an adjusting screwdriver. It has a rubber gasket or cone covering the exhaust channel.
Typically, valve material is brass and heat-resistant plastic.
Manual valve
Or the air valve for heating Majewski is a device for removing air in manual mode. The element is designed for installation on radiators of the heating system at the top point. The design assumes the presence of an exhaust valve on a thread with a flat slot for a screwdriver. The installation of the element in the system can be both in vertical and horizontal position with the outlet channel up.
Each time a new start-up of the system, after repair work or frequent pumping of water, this plunger is used. Gently unscrew the exhaust bolt with a screwdriver until a characteristic hiss of air appears through the drain hole. At the time of the appearance of water in it, the bolt is screwed back fully. Such an operation is carried out with all radiators.
Automatic valve
This mechanism is an essential element in the safety group of the boiler. It has an automatic valve, organized on the basis of a float mechanism.
In the initial state, when there is no air at the installation point of the plunger, the float is held by water pressure. The exhaust valve is closed. As soon as air begins to accumulate inside the float chamber, there comes a moment when the pressure drops and the float drops. An exhaust valve bleeds air. After that, the system returns to its original state.
An automatic air valve for heating is installed vertically in the system vertically. In addition to automatic operation, there is a mechanism for manual air release and forced shutoff of the air vent. The scope of the device is not limited only to heating systems, it can also be installed in:
- Pipelines.
- Air separators.
- Hot water systems - valve for water heater.
It is strictly forbidden to use the device in the field of application of oils and liquids on a mineral basis.
Rules for installing an air vent in the system
To effectively ventilate the system, the valves must be installed in areas with the greatest accumulation of air. These places are:
- The highest points of the system. This is due to the fact that air always tends to rise.
- Radiators This is especially true for aluminum-based heaters, as they chemically stimulate the process of decomposition of water into gaseous components.
- Risers, combs, separators.
- In collector-type heating, on each supply line in the collector.
- In the "warm floor" system - its highest points.
- An automatic air vent for heating is also installed in the boiler itself, in the heat exchanger.
It must be remembered that free access to the installation sites of the air vent valves should be provided, and the installation itself should be convenient for maintenance, repair and replacement.
Maintenance
Water contains salt solutions. In heating under the influence of temperature, these salts are deposited on the elements of the system, dirt can also penetrate and clog the channels. Therefore, a periodic check and implementation of preventive measures in all the most critical nodes is required. This is especially true for air and safety valves.
The first condition for the reliable operation of an automatic air plunger is to be under constant water pressure. The pressure must not fall below the 0.030 bar mark. This condition is ensured by embedding an expansion tank into the system. It has a rubber bulb under pressure.
In order not to become clogged and jam the vent valve of the air vent, the mechanism is periodically disassembled and subjected to cleaning. Also, the system cannot be operated without coarse filters. They also need to be inspected periodically.
When water seeps through the air valve for heating, and this cannot be eliminated by cleaning, it is more advisable to replace the device.
Conclusion
If during operation of the heating system the radiators, pipes began to make incomprehensible gurgling and gurgling sounds, if the system is unevenly heated or some of its elements do not heat up at all, pressure often drops, which means that it needs maintenance and airing.