Mayevsky crane - principle of operation, types, device
The coolant provides us with heat during the cold season. However, there are often situations in which the battery does not warm up completely. They occur due to the accumulation of air in the far part of the radiator, which prevents the radiator from filling with hot water. Therefore, it must somehow be removed. For this purpose, a Mayevsky crane is used, the principle of operation of which is based on bleeding air pockets when the shut-off cone valve is loosened.
A Mayevsky crane is installed at the top of the heating radiator. It can be controlled automatically or manually. When the valve is opened only half a turn, the air in the system comes out of it, making room for the coolant. This device is used on any types of radiators, including the old model.
Air locks inside the heating system inevitably appear in the following cases:
- when a new heating system is being installed;
- in case of repair of the system and removal of water from it;
- when installing new radiators;
- when air is sucked into the system during its operation;
- when there is a gradual release of air bubbles from the water, which is a natural physical phenomenon;
- in the presence of corrosive processes, which are accompanied by the release of a certain amount of air. Aluminum radiators are especially susceptible to such processes in city apartments.
The device and operation of the Mayevsky crane
The classic Mayevsky faucet is made of brass alloys, which are resistant to corrosion. It is a body, inside of which there is a cone needle valve. This Mayevsky valve is controlled by a shut-off screw, adjustable from the outside. Being in the closed position, the valve is able to securely hold the coolant inside the radiator. When the screw is turned to the side, the passage opening of the valve opens, releasing the air inside the heater.
The outside of the metal body often has a white plastic casing, giving the faucet a more refined and modern look. The device of the product may vary in its individual modifications, but the principle of operation of the Mayevsky crane always remains the same. Devices different external thread diameters, thanks to which it is possible to easily choose the right option for any radiator. There are taps with a thread of 1 inch, ¾ or ½ inch.
To control the adjusting screw, a Mayevsky crane key or a regular screwdriver is used. The four-sided key is convenient in that it takes up little space, allowing you to control the adjusting screw even if the radiator is in a hard-to-reach place.
In some cases, the operation of the crane can be controlled without the use of tools at all. To do this, it is enough to turn the valve by hand, ensuring the beginning of air bleeding.
Varieties
There are three types of air vents, differing in principle of operation and design:
1. Mayevsky manual crane. This is the simplest device that is controlled manually. If uneven heating of the radiator is detected, the tap can be opened with a key or any screwdriver, and then, as air leaves the radiator, turn the tap in the opposite direction.
2. Automatic faucet. The difference between an automatic crane is the absence of manual control of its operation. Its design and principle of operation are somewhat different from the functioning of a manual crane. The automatic faucet is made of brass in the form of a cylinder, but the needle valve is not provided for in its design. Instead, a plastic float is used. How does an automatic Mayevsky crane work? A plastic float, depending on the presence of air in the system, moves inside the tap and controls the opening and closing of the valve. Everything happens without human intervention. 
The photo above demonstrates the principle of operation of the Mayevsky automatic crane visually.
All automatic faucets have the ability to manually control what can be used when the passage hole is clogged.
3. Crane with built-in safety device. In this type of Mayevsky crane, the principle of its operation is somewhat different from the usual air bleeding. The safety valve is able to control the pressure of the coolant in the system. If the coolant pressure exceeds the limit value, reaching 15 atmospheres, the valve will work and begin to forcibly bleed the coolant from the heating system. This prevents damage to individual elements of the system in the event of.
Particularly relevant is the installation of air vents with safety valves in heating systems made of polypropylene and metal-plastic pipes, which may not withstand increased pressure.
Features of choice
When choosing a device model, you should consider some features of radiators:
How to install a Mayevsky crane
The installation of the valve is carried out without fail in the upper part of the radiator device from the side opposite to the flow of the coolant, since it is in this place that air is collected. Consideration should be given to the characteristics of each system. If a vertical heating system is installed in the house, then Mayevsky's taps are installed on the radiators of the upper floor. In addition, air vents are installed on all heating devices that are brought to the riser below the upper connection axis.
When using a horizontal system, the taps are mounted on all heating devices without exception, on which they can be connected.
If the Mayevsky crane is installed on a floor radiator located horizontally and parallel to the floor surface, then it is placed at the top of the highest point of the radiator. The adjusting screw points upwards.
Many bathrooms have heated towel rails that are heated by the heat carrier circulating inside them. On such devices, a Mayevsky crane for a heated towel rail is installed. Installation has some features. If the heated towel rail has a bottom connection, then a place is already provided for it to screw in the tap. But for models with lateral connection, it is necessary to refine. A tee cuts into the supply pipe, into which a tap is screwed. The air outlet should be directed away from the wall. It is desirable to equip some models of heated towel rails even with two air vents.
The procedure for installing a tap on a radiator
1. Before starting the installation of the tap, it is necessary to drain the water from the system.
2. Unscrew the cap located at the top of the radiator.
3. Screw the tap into place of the plug. The faucet is supplied with a rubber gasket as standard to ensure the tightness of its installation. For more reliable sealing, it is recommended to screw FUM-tape or oiled flax fibers onto the tap thread.
If a crane is being installed on an old cast iron battery, which does not have a hole, then the following refinement is performed. A hole is drilled in the cast-iron plug, which has a slightly smaller diameter than that of the tap thread. Threading is performed inside the cast-iron plug. After that, fitting and screwing in the air vent valve is performed.
Operation features
Consider how to use the Mayevsky crane. To do this, it is advisable to substitute some kind of container under the battery and stock up on a dry rag. Using a wrench or screwdriver, the locking screw is turned counterclockwise a quarter or half a turn. Air will hiss out of the system. When it comes out completely, water will flow from the tap. It is necessary to wait until the water begins to flow continuously. After that, the locking screw can be tightened.
If the air was successfully bled, and the battery remained cold, then this is a sign of clogging. To clean a clogged battery, you will have to resort to the help of plumbers.
Tip: If the heating system incorporates pumps that carry out forced circulation of the coolant, they must be turned off 10 minutes before the air is bled. When the pumps are on, air will not accumulate at the top of the radiator, but will be carried through the system by a stream of water.
If the faucet hole is clogged, it can be cleaned with a needle or other sharp object.
If the valve has not been used for a long time, the rotation of the adjusting screw may be difficult due to the formation of corrosion on it. If this situation occurs, use WD-40 lubricant spray. Just a few minutes after applying it to the screw thread, it can be easily unscrewed. At the end of the heating season, it is advisable to lubricate the adjusting screw with silicone grease. In this case, the thread will not be destroyed by the effect of the coolant on it.
If it is necessary to replace the Mayevsky crane, use two adjustable wrenches. With one key, you need to hold the plug on the radiator, and with the second - unscrew the tap. If this is not done, then unscrewing the tap can loosen the plug and lead to loss of its tightness.
We have dismantled how to bleed the Mayevsky crane from the system on our own and how to operate the device with automatic control. If you provide the necessary care for this device, check and clean it in a timely manner, the device will last a long time without causing any problems to its owners.
The price of a Mayevsky crane depends on its type, material of manufacture, diameter, and starts from 30 rubles.
