The main rule for the effective operation of water heating with a gas, electric or solid fuel boiler is good circulation of the coolant and the absence of air in the system. This is explained by the fact that air creates plugs, and it itself does not have good thermal conductivity and heat capacity. Therefore, it must be removed using special devices - needle-type cranes.
What is a Mayevsky crane
A faucet for venting air is an element of shut-off valves, the design of which is designed in such a way that allows, without blocking the heating system, to remove air from it by manually unscrewing the screw with a tapered end.
The term "tap" does not quite fit the definition of a device, since it is not designed to block the passage of the fluid passage. Mayevsky’s crane is a valve and at the same time a sensor, with the help of which a person bleeds air. A device of this type works provided that there is pressure in the system.
The concept of the Mayevsky crane is found only in domestic non-specialized sources. Professional as well as foreign literature calls this device a needle-type air valve for radiators. They come in different shapes, but the internal structure does not differ fundamentally.
Application area
Each node of the heating system can accumulate air, especially it is delayed in places with sharp turns, drops in the pipeline from top to bottom, in the area of changing the cross section from larger to smaller, in radiators.
All these sections need to be airy, what is the direct purpose of the Mayevsky crane. But it’s not always convenient to mount it.
The main difficulty is that the crane must be serviced by a person, so it is customary to cut it into those places of heating, where it is easy to get to and where nothing interferes with working with a screwdriver. Key installation points:
- Heating radiators. The Mayevsky crane is suitable for cast-iron radiators, steel and duralumin.
- Home-made steel heating registers.
- Expansion tank sealed heating system.
- Heated water towel rail.
- The top point of heating, for example, risers dead ends, where air can accumulate.
In addition to the Mayevsky crane, the system must be equipped with automatic air vent valves. This is due to the use of circulation pumps, which forcefully distill the coolant. Together with them, air jams will drift along the contour, and it is simply unrealistic to catch them with a needle valve.
How is the crane
Mayevsky crane device is quite simple. It consists of:
The case (base) is made of brass or bronze. Outside, it has threads for connection to points in the heating system. The thread is usually half an inch or three quarters, but inch threads are sometimes found. Also on the crane, a hexagon is provided for an open-end wrench for installation and disassembly. A thread is cut inside the case, which ends with a smooth cone. There are also two openings: one gauge for air inlet from the system, the other drain.
The screw is made of stainless steel and has a fine pitch thread. It is equipped with a head usually with a slot for a flat screwdriver. Sometimes the head is made in such a way that it is convenient to rotate with your fingers. On the other side of the screw, where the thread ends, there is a cone. It is carefully polished so that, combined with a cone in the case, not to let water through.
Sometimes the housing can be supplemented with a plastic sleeve that rotates freely around it. In this case, the drain hole is located in the coupling. It is combined with the channel in the housing. This makes it possible to bleed air in any direction by turning the clutch. Thus, when airing the system, you can not splash the walls or valuable objects with water.
Operating principle
The principle of operation of the Mayevsky crane is based on the property of air to rise up due to its lower density. Water displaces air, and it accumulates in places such as various branches, dead ends, often making air jams here. These areas are primarily equipped with needle valves.
The gas is directly adjacent to the tap calibration inlet. On the other hand, the channel is closed by a cone of a locking screw. When the screw is unscrewed, there comes a moment when the channel of the calibration hole is connected to the channel of the drain hole, and air can be released.
Since modern heating systems operate under pressure, the pressure begins to flow water to the open channel of the Mayevsky crane. Water, accordingly, presses on the air and displaces it, after which it itself rushes out. Due to the small cross section, its losses in this case are minimal.
When water has gone through the drain hole, the screw is screwed back in, the channels are closed, and the system returns to its original state. With the subsequent formation of an air plug, the entire cycle is repeated.
Installation Rules
By its nature, air rises, which is also observed in heating pipes. And if he got into an enclosed space, that is, when there is an exit only through the lower position of the pipe or radiator, he will not go anywhere and forms an air congestion. Such a plug may simply occupy part of the radiator, and it will not heat up well.
Therefore, Mayevsky cranes are installed based on the following principles:
- For each radiator of the heating system in the upper extreme corner opposite the water supply point.
- At the top of the expansion tank.
- At the top of the heating system at end points or dead ends.
Mayevsky's cranes supply the heating system during the period of its installation. The locking screw in all valves must be fully tightened. The crane itself is installed by wrapping a gasket on the thread so that there is no leakage. The most important thing is that the crane should be installed in the place where it has free access to carry out work on the system airing.
How to use the Mayevsky crane
After the heating has been started and the circulation pumps have driven the coolant through the pipes, all the air that has not come out through the automatic air vent valves accumulates in bubbles around the entire perimeter of the circuit. Now you need to remove it.
Any system consists of branches or lines. Each of them has its own beginning, that which is closer to the boiler, and its end, where the last radiator is installed. By airing the system with a Maevsky crane, they always go from the first radiator to the last. This is justified by the fact that in this direction the pumps drive liquid, and the discharged air cannot again form here.
To work with the crane, the following tool is required:
- slotted screwdriver for locking screw;
- a piece of matter to eliminate leaks.
The procedure for the work is as follows:
- The outlet of the needle valve is turned away from objects that are undesirable to wet.
- A piece of matter is brought to the hole so that it can be covered at any time and prevent leakage.
- Using a screwdriver, slowly unscrew the locking screw until a characteristic hiss of air escapes.
- After the air came out and water began to leak out, tighten the screw, eliminating smudges.
After passing all the Mayevsky cranes on batteries of one line, go to the next, and so on to the end. Warming up the system, go through and try the uniformity of temperature on each battery. If there are poorly heated ones, air is removed from them repeatedly.
Product Advantages and Disadvantages
The needle valve is a fairly reliable device, it:
- easy to maintain for any user;
- has a simple design, the principle of operation of the Mayevsky crane is understandable;
- durable and practically not clogged;
- refers to cheap valves, despite its indispensability in any heating.
The most important drawback of the needle valve is the inability to completely remove air, especially one that continuously circulates through the system. Because of this, it is necessary to install automatic air vents in parallel.
Maintenance
The Mayevsky crane rarely fails, but sometimes this happens if the water in the system is quite aggressive and contains a lot of salts. In this case, valve maintenance is simply necessary. A Mayevsky faucet for cast-iron radiators unscrews the locking screw and cleans the channels. It is more convenient to do this when replacing the coolant.
Conclusion
It is important to remember that installing a heating system is a complex undertaking, which only qualified specialists can do. If you decide to do the work on your own, it is advisable to have a reliable consultant in this matter.