How to bleed air from the heating system

The hot water heating system is able to work correctly only if there is no air in it. It periodically enters the circuit and, gradually accumulating, creates difficulties for the circulation of the coolant. It is impossible to prevent gas from getting inside, but you can remove it in time. For this, an air collector is used for the heating system.

Design and Functional Features

When the heated water flow begins to slow down its speed of movement, a volatile mass begins to stand out from the liquid. At this time, it is convenient to remove air from the heating system. Therefore, all collection units are in the form of a container in which as much of this substance can fit.

The second condition is that the design and installation position of the device are chosen so that the flow inside the device slows down its speed. As a rule, the most suitable installation point is at the highest point of the heating line.

Types of devices with different operating principles

After separation and accumulation in the container, the gas must be driven out. For this, one air trap is not enough; removal devices are needed. Such elements are understood as special plumbing mechanisms - air vents. They are mounted directly on the body of the device.

There are two types of such devices: some work in manual mode, others automatically release gas.

Automatic bleeding mechanisms

At the points of the greatest probability of gas accumulation in the pipes, automatic elements are installed to remove it. Usually, such places can be sharp bends of pipes, changing the direction of movement of the coolant from top to bottom or any other upper points. There is also an automatic air vent for the radiator.

Manual gas removal from a warm circuit

All heating radiators are supplied with manual valves. It is more expedient to do this due to the relative cheapness of such elements and the absence of the risk of stopping the operation of the entire boiler room if one of the convectors is airy and stops functioning.

With the help of manual air vents, it is possible to bleed air from the heating radiator immediately after starting the boiler equipment or restarting during repairs.

Types of air collectors

Based on the principle of installing the air collector in the system, there are:

• flowing devices;
• non-flow type devices.

Both those and others have the form of a cylinder with smooth or elliptical ends with a diameter greater than the diameter of the pipe into which they are directly cut. In terms of their internal structure, they may differ slightly, but the principle of operation is the same.

Flowing

Such elements are directly installed in the cut of the supply and return pipes of the boiler house. Liquid is constantly forced through the structure by a pump. The air, gradually evolving from the water, leaves through the vent.The advantage of the system is that the entire volume of the coolant passes through the trap, so a large percentage of the gas can be removed. The second plus is that the unit is protected from freezing due to continuous movement inside it. The air collector can be installed indoors without heating.

Impervious

Non-flowing units are free-standing elements that are cut into the line with only one end, usually located at the top. Bubbles rush into them through the pipe. In this case, there is a likelihood of a poorer purification from oxygen if the speed of the coolant is high enough and not all bubbles can separate from the total mass in time and enter the air receiver. Another inconvenient point is the risk of such a container freezing in winter, so its installation must be carried out in a heated room.

The principle of separation of the gaseous mass from the coolant

Air is dissolved in water when it is cold. As the circuit heats up, oxygen begins to evolve, combining into bubbles. They are located in the heating medium flow and occupy the upper space due to their lighter weight. At the moment of transition from a thin tube to a thick one, the fluid velocity drops, giving the bubbles the opportunity to press against the upper wall of the channel. On this principle, the separation of matter takes place.

Separator of vertical design

This cylinder looks like an expansion tank. Such a separator is used in a two-pipe system, where there is a vertical riser. At the highest point of the pipe with a minimum speed of movement of the coolant, this flow-through device is installed. The inlet and outlet goes from the bottom end, there is also a threaded tube for the drain. The separator is equipped with a drain cock or an automatic gas vent.

If a manual valve is installed to remove oxygen, the separator should be checked periodically to ensure that it does not completely fill up with volatile matter and itself cause an air lock.

Separator horizontal design

The horizontal unit is more often used for single-pipe circuits. They cut it in succession to the radiators before or after the boiler. This cylinder has a larger diameter than the supply pipe. Due to its size, the liquid slows down movement. A manual or automatic air vent is also installed in the upper part of the element, the inlet and outlet are located at both ends of the cylinder. For such a mechanism, it is not important that its location is at the highest point.

Automatic valve

The mechanism has a small internal container that contains the float, lever and nipple valve. All these elements are interconnected. If there is water in the chamber, the float is lifted up and the lever keeps the nipple valve closed. As soon as the gases get inside through the connecting pipe, the float descends and, under its own weight, pulls the lever down - the valve releases air.

Mayevsky's manual crane

This element helps to release air from the battery. It is installed mainly at the top of the radiators. Reset occurs when the needle valve is unscrewed. You need to use the device every time after restarting the system, or when the convector is cold for some reason.

Water-folding taps

Conventional ball valves are sometimes used to vent air. They are easy to use, reliable, but you need to be careful when opening such a tap - the large diameter of the passage channel contributes to the rapid release and the same quick splashing of hot water under pressure.