The article shows the types of automatic air vents, types of valves in the heating system and disassembled the principle of operation of the vent.
Types of automatic air vents
In total, there are three varieties of these devices - despite this, the operation of an automatic air vent, or rather its principle, remains unchanged. In all cases, the same needle valve is used and the same float opens and closes it - the difference is only in the position of the body relative to the connecting pipe, i.e. threaded connection.
direct automatic air valve for heating. The most common automatic air removal device. It is designed for vertical installation only - 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 for their application is pipelines, or rather their upper points, where, according to all the laws of physics, the air formed in heating rushes. If it were not for such devices, then it would be very inconvenient to discharge 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 part of the boiler safety group, which also includes a pressure gauge and an explosion valve. Air vents are also equipped with indirect heating boilers and other equipment, at the top of which there is a possibility of air accumulation.
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- Types of automatic air vents
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 threaded side outlet. 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 outlet connecting pipe with a thread changes and, as a result, the appearance of the Mayevsky automatic crane. A very important condition for the correct functioning of the corner air vent machine is the strictly vertical installation of its body. Horizontally and even at an inclination with a slight angle, the machine will not be able to work adequately - the float will get stuck and, as a result, air removal will be untimely or it will not be performed at all.
Automatic air vent for radiators. In fact, this is a kind of corner air vent machine, although you can’t tell it from the outside - all these nuances are hidden inside the case. The outer part of the battery air vent is created for aesthetic reasons. 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 futhor nuts. On old batteries, they are mounted through a futorka with a threaded through hole, and for steel convectors, special machines with a half-inch pipe are used.
This and all the varieties that an automatic air valve for heating systems can boast of. In principle, more is not needed, since despite the various installation conditions, one of them will still work.
Valve on the radiator for air release
Safety valve
In most models of modern boilers, manufacturers provide a security system, the “key figure” of which is safety fittings included directly in the boiler heat exchanger or in its piping.
The purpose of the safety valve in the heating system is to prevent an increase in pressure in the system above the permissible level, which can lead to: destruction of pipes and their connections; leaks; explosion of boiler equipment The design of this kind of fittings is simple and unpretentious.
The device consists of a brass body containing a spring-loaded locking membrane connected to a stem. The elasticity of the spring is the main factor that
keeps the membrane in the locked position. The adjusting knob adjusts the compression force of the spring.
When the pressure on the membrane is higher than the set one, the spring is compressed, it opens and the pressure is released through the side hole. When the pressure in the system cannot overcome the elasticity of the spring, the membrane will take its original position.
Tip: Get a safety device with pressure adjustment from 1.5 to 3.5 bar. Most models of solid fuel boiler equipment fall into this range.
Air vent
Air congestion. As a rule, they appear for several reasons:
- boiling of the coolant;
- high air content in the coolant, which is automatically added directly from the water supply;
- As a result of air leakage through leaky connections.
The result of air pockets is uneven heating of radiators and oxidation of the internal surfaces of the metal elements of CO. The air release valve from the heating system is designed to vent air from the system in automatic mode.
Structurally, the air vent is a hollow cylinder made of non-ferrous metal, in which a float is located, connected by a lever to a needle valve, which, in the open position, connects the vent chamber to the atmosphere.
In working condition, the internal chamber of the device is filled with coolant, the float is raised, and the needle valve is closed. When air enters, which rises to the upper point of the device, the coolant cannot rise in the chamber to the nominal level, and therefore, the float is lowered, the device operates in the outlet mode. After the air escapes, the coolant rises in the chamber of this type of fitting to the nominal level, and the float takes its regular place.
check valve
In a gravity-flowing CO, there are conditions under which the coolant can change the direction of movement. This threatens to damage the heat generator heat exchanger due to overheating. The same can happen in rather complex CO with forced movement of the coolant, when water, through the bypass pipe of the pump unit, enters the boiler back. The mechanism of action of the check valve in the heating system is quite simple: it allows the coolant to pass only in one direction, blocking it when moving back.
There are several types of this kind of fittings, which are classified according to the design of the locking device:
- poppet;
- ball;
- petal;
- bivalve.
As the name implies, in the first type, a steel spring-loaded disk (plate) connected to the stem acts as a locking device. In a ball valve, a plastic ball acts as a shutter. Moving "in the right" direction, the coolant pushes the ball through the channel in the body or under the cover of the device. As soon as the circulation of water stops or the direction of its movement changes, the ball, under the influence of gravity, takes its original position and blocks the movement of the coolant.
In the petal, the locking device is a spring-loaded cover, which falls when the direction of water in CO changes under the influence of natural gravity. The double-leaf element is installed (as a rule) on pipes of large diameter. The principle of their work does not differ from the petal. Structurally, in such fittings, instead of one petal spring-loaded from above, two spring-loaded flaps are installed. These devices are designed to adjust the temperature, pressure, as well as stabilize the operation of CO.
balancing valve
Any CO requires hydraulic adjustment, in other words, balancing. It is carried out in various ways: with correctly selected pipe diameters, washers, with different flow sections, etc. The most effective and at the same time simple element for setting up CO operation is considered to be a balancing valve for the heating system.
The purpose of this device is to supply the required volume of coolant and the amount of heat to each branch, circuit and radiator.
The valve is a conventional valve, but with two fittings installed in its brass body, which make it possible to connect measuring equipment (pressure gauges) or a capillary tube as part of an automatic pressure regulator.
Principle of operation balancing valve for the heating system is as follows: By turning the adjusting handle, it is necessary to achieve a strictly defined flow rate of the coolant. This is done by measuring the pressure at each fitting, after which, according to the diagram (usually attached by the manufacturer to the device), the number of turns of the adjusting knob is determined to achieve the desired water flow for each CO circuit. On circuits with up to 5 radiators, manual balancing regulators are installed. On branches with a large number of heating devices - automatic.
bypass valve
This is another CO element designed to equalize the pressure in the system. The principle of operation of the bypass valve of the heating system is similar to the safety valve, but there is one difference: if the safety element bleeds excess coolant from the system, then the bypass valve returns it to the return line past the heating circuit.
The design of this device is also identical to the safety elements: a spring with adjustable elasticity, a shut-off membrane with a stem in a bronze case. The flywheel adjusts the pressure at which this device operates, the membrane opens the passage for the coolant. When the pressure in CO is stabilized, the membrane returns to its original place.
Based on materials from sites: ventilationpro.ru, stroisovety.org