The operation of the heating system is a balanced process, which must be monitored automatically. In addition to maintaining the optimal temperature of the water in the pipes, safety measures should be taken in the event of emergency situations. First of all, this is a sharp jump in pressure in the line. For this, a safety group is installed in the heating circuit.

During the operation of the heating boiler, the coolant is exposed to temperature effects. This leads to its expansion and increase in pressure in the pipes. There are optimal parameters that should be considered when designing a heating system:

• Temperature - from 65 ° С to 95 ° С.
• Pressure - up to 3 atm.

To a large extent, these parameters also depend on their physical characteristics.

V open systems heating compensation takes place at the expense of an expansion tank. But if the system closed type, then you cannot do without observing security measures.

Most gas boilers and some solid fuel models are equipped with a pressure and temperature control system. But there is always the possibility of its failure. It is for such unforeseen situations that you need to install a security group.

Structurally, it consists of the following elements:

Pressure gauge

Indicates the current pressure in the system. In addition, additional scales for maximum and minimum pressure indicators are provided in the device for visual control.

Air vent

With a sharp increase in water temperature, steam is released in the system. For quick stabilization, it is necessary to quickly remove the excess air, which is what the air vent does. Additional functions are protection of heating elements from rapid corrosion, reduction of the noise level during the operation of the system.

Safety valve

Heating of the coolant is also accompanied by its expansion. The excess is removed by means of a safety valve, which is triggered when a certain pressure is reached. Usually it is adjusted to a maximum value of 2.5-3 atm.

This is the basic configuration of the security group. In addition to the above elements, it may include additional temperature sensors.

Mounting

The correct functioning of the security team depends largely on the professional attitude. During the design of heating, they always provide for the installation of shut-off valves, which cut off the flow of the coolant when carrying out renovation works, or replacements individual elements... At the same time, they often make the mistake of installing a ball valve in front of a security system.

This is a gross violation of the installation rules, since when overlapped, the security system will not be able to perform its functions. It is best to consider a similar situation with a specific example.

Suppose there was a pipe breakdown - a leakage caused by water leakage. It is not possible to quickly extinguish a solid fuel boiler. It will generate heat for some time. If shut-off valves is installed according to the above scheme, then its overlap cuts off the safety group from the boiler operation system. At this time, the coolant heats up, the pressure rises, but the mechanism for stabilizing it remains out of operation. And for obvious reasons, either a breakdown of the heating equipment occurs, or a rupture of the pipeline.

To avoid this situation, the installation should be carried out according to the following diagram:

Guided by this principle of installation, you can safely carry out any repair and maintenance work without worrying about the safety of highways and heater... After installation, the device is activated by opening the cap on the automatic air vent. In no case should you remove it completely. Also, a visual inspection of the valve is carried out at least once a month. If it does not work for a long time, then a layer of dirt appears between the seat and the device plate. In the future, this can lead to the occurrence of leaks. To flush it without dismantling, it is enough to turn the structure according to the arrow indicated on it.

Price

The cost of security groups is largely determined by the manufacturer, device parameters and additional functions... The main criterion is the power of the heater. Based on this, the choice of one or another model is made.

Users individual systems heating systems are obliged to independently ensure that the heating equipment functions as safely as possible. For this purpose, a safety group must be installed in the heating system, since it will prevent excessive pressure and minimize the risk of air bubbles, so that all devices will be fully functional. Such a group is a set of devices that ensure trouble-free operation of the network and control the pressure of the working fluid.

More details about what a security group is, what elements it consists of and how it is installed, and will be discussed in today's article.

Popular manufacturer, prices

For the convenience of users, information on manufacturers is given in the form of a small table.

Table 1. Manufacturer of heating safety groups

Name	Available Models	Description	Average market value, in rubles
ARS	They are produced in two modifications - Professional (have a round shape) Standart (can be of two types - square and brass).	All models are designed to protect a closed heating system, as well as to install an expansion tank.	1308 to 1422
Fado	It is produced in just one modification, namely Fado-1.	Brass safety panel in the heating system, which can be used with a heat generator, tank or underfloor heating system. Weighs 550 grams.
	It is produced in two modifications - for the protection of the heating boiler and for the protection of the expansion tank.	The connection is of the lower type, the nominal pressure is 10 atmospheres. The temperature of the working fluid should not exceed 110 degrees. Another feature of the models is the internal thread.	From 2965 to 3320 (depending on modification)
Watts	These groups are available in five modifications, but all of them are intended to protect the heating boiler. The following Watts block models are available on the market: - KSG-30; - KSG-30 N; - KSG-30 / 20M-ICO; - KSG-30 / 25M-ІСО	All these modifications are made on a steel console (the only exception is the KSG-30 N, in which all the elements are inside the brass body). Installed above the heat generator, in a vertical position.	2625 to 5650

As you can see, the choice is quite large, but for quality - in fact, as elsewhere - you will have to pay more.

The main causes of water hammer in the water supply system

Earlier we talked about why it occurs and how to prevent water hammer in the heating system, in addition to this article, we advise you to read this information

Structural elements of the device

Any security group is a metal case that contains the following devices:

1. safety valve;
2. pressure gauge;
3. air vent.

Let's figure out the structure and purpose of each of the elements.

Element number 1. Safety valve

Such a valve is designed to protect the heating system from excessive high pressure... There is a certain pressure indicator for which this device is designed, and as soon as it (indicator) is exceeded, it is triggered and all unnecessary is dumped. In principle, in heating, the pressure is compensated with the help of an expansion tank: when the liquid heats up, its surplus enters the tank, due to which the pressure in the network remains constant, and the system itself does not suffer from this. Typically, the total volumes of the working fluid remain the same.

But in some cases, the tank does not work. And it is for this kind of cases that a safety valve is required that will dump excess fluid from the network. To prevent water from leaking onto the floor, a hose must be connected to the thread, which is led out into the sewer. And one more conclusion can be drawn from this: there must be a sewage system in the boiler room.

Note! In this case, in no case should it be poured into sewerage system antifreeze (if used as a coolant).

At the top of the valve there is a handle (often red), through which the functionality of the device is checked. To do this, you just need to turn the handle in the direction where the arrow points, after which water should flow; if it stops flowing after the handle is already released, then the valve is operating normally. If the flow of water continues, then you need to open / close the valve several more times - usually after that everything returns to normal.

If the water does not want to stay in the valve, it should be replaced as soon as possible. More fluid can leak out if the valve is not tight enough in the seat. It should be noted that fuses are manufactured with the expectation of various indicators pressure, and when choosing one or another option, you should be based on the pressure for which your heat generator is designed. For a private house, for example, a 3 atmosphere valve is required.

But what if the heating safety group with the required fuse is not available for sale? In such cases, it is better to purchase all the devices separately, and assemble the group at home with your own hands (more on this later).

Element number 2. Pressure gauge

The main purpose of the pressure gauge is to adjust the pressure in the line. They, as well as the fuses described above, can be designed for different pressure ratings in order to maximize operating comfort. To find out the readings of a particular device, you just need to carefully examine its case (usually this is quite enough).

Due to the fact that in private houses the pressure is mainly 2 or 3 atmospheres, then the device should also be designed for a maximum of 4 atmospheres.

There are two arrows on the device itself - black (it is also working) and red (necessary for control). The second arrow must be manually set to the required mark (as a rule, to 2 atmospheres, for heat generators floor mounting more is not needed; although a specific indicator is indicated in technical documentation). And if the black arrow "went" further than the red one during operation, it means that the pressure has increased too much.

Element number 3. Automatic air vent

The safety group must be installed in the upper part just because of the air vent - the fact is that it must be located at the highest point where air bubbles are directed. In fact, this is another type of Mayevsky crane that can function automatically. It is not necessary to twist or unscrew it, since the air is removed in automatic mode. When emergency this device is truly irreplaceable. For example, the temperature controller can suddenly stop working, which can cause the process fluid in the heat generator to boil. And at this time, air can be released, which, with an absolute guarantee, will violate the integrity of the entire system.

And with the help of an air vent, this element of the safety group in the heating system, it - air - removal will be carried out.

Note! A prerequisite for the normal functioning of a security group is its competent installation. The slightest mistake during editing deprives the use of the group of any meaning and it may simply not work in the event of a critical situation.

Video - Security group and heating system

The principle of operation of such a group

Now imagine that for some reason, the expansion tank - purely hypothetically - suddenly did not compensate for the thermal expansion of the coolant, which is so important in the operation of the entire heating system. In this case, the pressure in the line will begin to rise. Then the safety valve is triggered: the spring in it is no longer able to hold the working fluid, it is compressed, which opens the valve and the pressure is finally released.

How does all this happen?

1. Phase one. Excess air is discharged through an air vent.
2. Phase two. Excess working fluid is drained through a special outlet in the safety valve.

Note! In order to avoid accidental burns in the event of a sudden actuation of the valve and the discharge of excess working fluid, a special hose or tube is connected to the outlet, which must be removed to the sewer system.

The main types of heating safety groups

The configuration of safety blocks, as noted above, can be very diverse. There is, for example, this option.

Or here's another option, in which all the elements are enclosed in a single body.

A few more options.

Many other options for performing a security group are on sale, but external indicators in this case do not matter, since the principle of operation is the same for all of them. To choose one or another model should, we repeat, according to the pressure indicator for which the pressure gauge and the safety valve are designed.

Now, having dealt with the main types of groups, let's get acquainted with popular manufacturers and approximate cost such products.

Where to install the safety box?

In the case of a wall-mounted heating boiler, you do not have to worry about anything at all, since the manufacturer has already taken care of everything: the safety group is already on the back wall or inside the device itself.

But for boilers floor type units must be purchased separately and installed by yourself. Where exactly? On the supply pipe, in the maximum proximity to the heat generator (that is, no further than 100-150 centimeters from it). As for the pressure gauge, it must be installed so that all of its readings are clearly visible. You also need to clearly see the working fluid that flows out of the safety valve, which you should also be aware of before starting installation work.

Installation features

First, you need to briefly talk about shut-off ball valves (later you will find out why exactly). When arranging the heating system, care must be taken that if any of the elements breaks down, it can be easily replaced or, alternatively, repaired, and without draining the coolant from the entire system. It is for this purpose that ball valves are installed.

Let's say the battery has leaked. In this case, you just need to close the shut-off valves - before and after the battery - and then remove the battery itself. The heating system will then continue to function, which is extremely important if it is cold enough outside. In the absence of such taps, you will have to drain all the working fluid from the line. This will take a lot of effort and time, and, more importantly, the system will not work at this time.

And now we have a security group directly in the heating system. Below is the short instruction, from which you will learn in which order the unit should be installed.

Step 1. The safety group should be placed on the supply pipe, no more than 100-150 centimeters from the heating boiler.

Step 2. Without the required knowledge, many, when installing this device, put cut-off taps between it and the heat generator, or, alternatively, directly on the group itself. Their explanation looks like this: if the boiler fails, then it can be easily fixed or replaced. Below are two options for improper installation of isolation valves.

In each of the examples, the taps are installed incorrectly, and if the heat generator fails, then the seller will refuse you a guarantee, since the device was not installed as needed. With this kind of valve arrangement, the risk of overheating the system increases, which can lead to boiler breakdown.

Step 3. At competent installation cranes should be located behind the safety group. This is correct, and in this case, no one will refuse you a guarantee.

Video - How to connect a security group

Making a security group at home

Many people are interested in whether it is possible to make such a group with their own hands? It is possible, but for this you need to separately purchase each of the elements, and then connect them through adapters, tees, and so on. The body of the block can be welded from pieces of fittings and pipes made of polypropylene - it will cost much less than the “store” version made of brass.

At the same time, do not forget that the polypropylene safety group can be installed only in those lines where the temperature of the working fluid is low (for example, in the "warm floor" system), but in no case in the batteries! This is because if the liquid heats up to 95 degrees, it will lead to the destruction of polypropylene, and the consequences of this can be the most unpredictable.

Video - Security Group

Good day, my dear reader! In this article, I will briefly tell you why you need a security group in the heating system, and also tell you about the rules for installing it. So let's start with the definition.

What is a security group?

A security group is a node that combines several devices. Standard set security group devices will be as follows:

• A pressure gauge is a device that shows the pressure in the heating system.
• Automatic air vent - serves to remove from the system air congestion.
• The safety valve is the main part of the group that relieves pressure if it is exceeded.

The standard security group includes safety valve, designed for a pressure of 3 atmospheres.

How does a safety valve work?

Let's take a closer look at the safety valve. Consider it internal organization and the principle of work:

Safety valve device

It can be seen from the top figure that the operating principle of the valve is very simple. Inside it is a piston, which is pressed against the valve seat by means of a spring. As soon as the pressure becomes large enough to raise the piston, the coolant is dumped into some container or even on the floor.

In the standard safety group, there is a valve designed to discharge at a pressure of more than 3 atmospheres. It must be remembered that the boiler is the weakest point in the heating system (by pressure), therefore the safety group is selected according to the pressure for which it is designed.

Security group installation rules.

During the installation of the boiler safety group, the following rules must be observed:

• the pressure gauge, air vent and safety valve must be screwed onto the console and all connections must be checked for leaks.
• The safety group must be installed above the boiler level. Or for a special seat, which should be on top of the boiler, or on the supply pipe. In the second option, the group should be up to the first taps.
• For proper operation of the air vent, the group must be positioned vertically.
• For drainage, you can use a pipe no more than 2 meters long. The number of tube bends should not exceed 2. If you need to increase the length of the tube or the number of bends, then you need to increase its inner diameter. For example, if a standard valve has a 0.5-inch thread, then in the case of a short tube (less than 2 meters long), you can take metal-plastic pipe with a diameter of 16 mm, and if the drainage is longer or has more than two bends, then you will have to use a metal-plastic pipe with a diameter of 20 mm.

The safety group is installed above the boiler.

Summary of the article.

A security group is essential! The heating system can fail without it. Moreover, the most expensive part of the system - the heating boiler - will fail. Therefore, do not skimp on this node! Now there are many shops on the shelves different options groups, but personally I advise you to focus on models European manufacturers... They are made of better quality materials and work more stably. That's all, write your questions in the comments, use the buttons of social networks!

In the past few years, a closed heating system has become more and more popular. heating equipment becomes more and more expensive, and I want it to last longer. In closed-type systems, the possibility of free oxygen getting inside is practically excluded, which prolongs the life of the equipment.

Closed heat supply system - what is it

As you know, in any heating system of a private house there is an expansion tank. This is a container that contains some weaning of the coolant. This tank is required to compensate for thermal expansion under various operating conditions. By design, expansion tanks are open and closed, respectively, and heating systems are called open and closed.

V last years becomes more and more popular namely closed circuit heating. First, it is automated and works without human intervention for a long time. Secondly, any type of coolant can be used in it, including antifreeze (it evaporates from open tanks). Thirdly, the pressure is kept constant, which makes it possible to use any household appliances... There are a few more pluses that relate to wiring and operation:

• There is no direct contact of the coolant with air, therefore, there is no (or almost no) incoherent oxygen, which is a powerful oxidizing agent. This means that the heating elements will not oxidize, which will increase their service life.
• The closed-type expansion tank is placed anywhere, usually not far from the boiler (wall-mounted gas boilers come immediately with expansion tanks). Tank open type should stand in the attic, and these are additional pipes, as well as insulation measures so that heat does not "leak" through the roof.
• In a closed system, there are automatic air vents, so there is no airing.

In general, a closed heating system is considered more convenient. Its main drawback is volatility. The movement of the coolant is provided by a circulation pump (forced circulation), and it does not work without electricity. Natural circulation in closed systems can be organized, but it is difficult - flow regulation is required using the thickness of the pipes. This is a rather complicated calculation, because it is often believed that a closed heating system works only with a pump.

To reduce volatility and increase the reliability of heating, they put blocks uninterruptible power supply with batteries and / or small generators that will provide emergency power.

Components and their purpose

In general, a closed heating system consists of a specific set of elements:

• Boiler with safety group. There are two options here. First, the safety group is built into the boiler (gas wall-mounted boilers, pellet and some solid fuel gas generators). The second - there is no safety group in the boiler, then it is installed at the outlet in the supply pipeline.
• Pipes, radiators, convectors.
• Circulation pump. Provides the movement of the coolant. It is installed mainly on the return pipeline (here the temperature is lower and there is less possibility of overheating).
• Expansion tank. Compensates for changes in the volume of the coolant, maintaining a stable pressure.

Now more about each element.

Boiler - which one to choose

Since the closed heating system of a private house can work in autonomous mode, it makes sense to install a heating boiler with automation. In this case, having adjusted the parameters, you do not need to return to this. All modes are supported without human intervention.

The most convenient gas boilers in this regard. They have the ability to connect room thermostat... The temperature set on it is maintained with an accuracy of one degree. She fell by a degree, the boiler turned on, heating the house. As soon as the thermostat is triggered (temperature reached), operation stops. Comfortable, convenient, economical.

Some models have the ability to connect weather-dependent automation - these are external sensors. According to their readings, the boiler adjusts the power of the burners. Gas boilers in closed heating systems are good equipment that can provide comfort. The only pity is that gas is not available everywhere.

No less automation can be provided by electric boilers... In addition to traditional units, induction and electrode units have recently appeared on heating elements. They are compact in size and low inertia. Many believe that they are more economical than boilers with heating elements. But even this kind of heating units can not be used everywhere, since power outages in winter time- a frequent occurrence in many regions of our country. And to provide power to the boiler. 8-12 kW from a generator is a very difficult matter.

More versatile and independent in this regard are boilers on solid or liquid fuel. An important point: for the installation of a liquid fuel boiler, a separate room is required - this is a requirement of the fire department. Solid fuel boilers can stand in the house, but this is inconvenient, since a lot of debris falls from the fuel during the heating.

Modern solid fuel boilers, although they remain intermittent equipment (they heat up during the furnace, cool off when the bookmark burns out), but they also have automation that allows you to maintain a given temperature in the system by adjusting the intensity of combustion. Although the degree of automation is not as high as that of gas or electric boilers, it is there.

Pellet boilers are not very common in our camp. In fact, this is also solid fuel, but boilers of this type operate continuously. Pellets are automatically fed into the firebox (until the stock in the burker is finished). At good quality fuel, ash cleaning is required once every few weeks, and all operating parameters are controlled by automation. The distribution of this equipment is held back only by its high price: manufacturers are mainly European, and their prices are corresponding.

A little about calculating the boiler power for closed-type heating systems. It is determined by general principle: 10 sq. meters of area with normal insulation take 1 kW of boiler power. Only take "back to back" is not advised. First, there are abnormally cold periods in which you may not have enough design capacity. Secondly, operation at the power limit leads to rapid equipment wear. Therefore, it is advisable to take the boiler power for the system with a margin of 30-50%.

Security group

A safety group is installed on the supply pipeline at the outlet of the boiler. She must control his work and system parameters. Consists of a pressure gauge, an automatic air vent and a safety valve.

The pressure gauge makes it possible to monitor the pressure in the system. According to the recommendations, it should be in the range of 1.5-3 Bar (in one-story houses this is 1.5-2 Bar, in two-storey ones - up to 3 Bar). In case of deviation from these parameters, appropriate measures must be taken. If the pressure has dropped below normal, it is necessary to check whether there is a leak anywhere, and then add a certain amount of coolant to the system. At high blood pressure everything is somewhat more complicated: it is necessary to check in what mode the boiler is operating, whether it has overheated the coolant. The work is also checked circulation pump, correct operation of the pressure gauge and safety valve. It is he who must dump the excess coolant when the pressure threshold is exceeded. A pipe / hose is connected to the free branch pipe of the safety valve, which is discharged into the sewer or drainage system... Here it is better to do so that it is possible to control whether the valve is triggered - with frequent water discharge, it is necessary to look for the causes and eliminate them.

The third element of the group is an automatic air vent. Through it, the air that has entered the system is removed. Highly convenient device, which allows you to get rid of the problem of air congestion in the system.

Security groups are sold assembled (pictured above), or you can buy all the devices separately and connect them using the same pipes that made the system wiring.

Expansion vessel for a closed heating system

The expansion tank is designed to compensate for the change in the volume of the coolant depending on the temperature. In closed heating systems, this is a sealed container, divided into two parts by an elastic membrane. The upper part contains air or inert gas (in expensive models). While the temperature of the coolant is low, the tank remains empty, the membrane is straightened (in the figure, the picture on the right).

When heated, the coolant increases in volume, its surplus rises into the tank, pushing the membrane and squeezing the gas pumped into the upper part (in the picture on the left). On the pressure gauge, this is displayed as an increase in pressure and can serve as a signal to reduce the intensity of combustion. Some models have a safety valve that relieves excess air / gas when the pressure threshold is reached.

As the coolant cools down, the pressure in the upper part of the tank squeezes the coolant out of the tank into the system, the manometer readings return to normal. That's the whole principle of operation of a membrane-type expansion tank. By the way, there are two types of membranes - disc-shaped and pear-shaped. The shape of the membrane does not affect the principle of operation.

Volume calculation

According to generally accepted standards, the volume of the expansion tank should be 10% of the total volume of the coolant. This means that you have to calculate how much water will fit in the pipes and radiators of your system (it is in the technical data of the radiators, but the volume of the pipes can be calculated). 1/10 of this figure will be the volume of the required expansion tank. But this figure is valid only if the coolant is water. If an anti-freeze fluid is used, the tank size is increased by 50% of the calculated volume.

Here is an example of calculating the volume membrane tank for a closed heating system:

• the volume of the heating system is 28 liters;
• expansion tank size for a system filled with water 2.8 liters;
• the size of the membrane tank for the system with antifreeze liquid is 2.8 + 0.5 * 2.8 = 4.2 liters.

When buying, choose the nearest larger volume. Do not take the smaller one - it is better to have a small margin.

What to look for when buying

Stores have cisterns of red and of blue color... Red cisterns are suitable for heating. Blue are structurally the same, only they are intended for cold water and high temperatures do not tolerate.

What else should you pay attention to? There are two types of tanks - with a replaceable membrane (they are also called flanged) and with an irreplaceable one. The second option is cheaper, and significantly, but if the membrane is damaged, you will have to buy the whole thing. In flanged models, only the membrane is purchased.

Place for installation of a membrane-type expansion tank

Usually, an expansion tank is placed on the return pipe in front of the circulation pump (if viewed in the direction of movement of the coolant). A tee is installed in the pipeline, a small piece of pipe is connected to one part of it, and an expander is connected to it through fittings. It is better to place it at some distance from the pump so that pressure drops are not created. An important point is that the piping section of the membrane tank must be straight.

A ball valve is installed after the tee. It is necessary to be able to remove the tank without draining the coolant. It is more convenient to connect the container itself using an American (union nut). This again facilitates assembly / disassembly.

Please note that some boilers have an expansion vessel. If its volume is sufficient, the installation of the second is not required.

An empty device does not weigh much, but a filled with water has a solid mass. Therefore, it is necessary to provide for a method of fixing on the wall or additional supports.

Circulation pump

The circulation pump ensures the operability of the closed heating system. Its capacity depends on many factors: the material and diameter of the pipes, the number and type of radiators, the presence of shut-off and thermostatic valves, the length of the pipes, the operating mode of the equipment, etc. In order not to go into the intricacies of calculating power, the circulation pump can be selected from the table. Choose the nearest greater importance according to the heated area or the planned heat output of the system, in the corresponding line in the first columns find the required characteristics.

In the second column, we find the power (what volume of the coolant he is able to pump in an hour), in the third - the pressure (resistance of the system), which he is able to overcome.

When choosing a circulation pump in a store, it is advisable not to save money. The entire system depends on its performance. Therefore, it is better not to save money and choose a trusted manufacturer. If you decide to buy unknown equipment, you need to somehow check it for noise levels. This indicator is especially critical if the heating unit is installed in a residential area.

Strapping scheme

As mentioned earlier, circulation pumps are installed mainly in the return pipeline. Previously, this requirement was mandatory, today it is only a wish. The materials used in the production can withstand heating up to 90 ° C, but still it is better not to risk it.

In systems that can work with natural circulation, during installation, it is necessary to provide for the ability to remove or replace the pump without the need to drain the coolant, as well as to be able to work without a pump. For this, a bypass is installed - a bypass path through which the coolant can flow if necessary. The installation diagram of the circulation pump in this case is in the photo below.

In closed systems with forced circulation a bypass is not needed - it is inoperative without a pump. But here are two ball valves on both sides and an inlet filter is needed. Ball valves make it possible, if necessary, to remove the device for maintenance, repair or replacement. A mud filter prevents clogging. Sometimes like additional element reliability, between the filter and the ball valve they put another check valve, which will prevent the movement of the coolant in the opposite direction.

Diagram of connection (piping) of a circulation pump to a closed-type heating system

How to fill a closed heating system

At the lowest point of the system, as a rule, on the return pipeline, an additional valve is installed to feed / drain the system. In the simplest case, this is a tee installed in the pipeline, to which through small area the pipe is connected to a ball valve.

In this case, when draining the system, it will be necessary to substitute a container or connect a hose. When filling the coolant to ball valve the hose is connected hand pump... This simple device can be rented from plumbing stores.

There is a second option - when the coolant is simple tap water... In this case, the water supply is connected either to a special input of the boiler (in wall gas boilers), or to a ball valve similarly installed on the return line. But in this case, another point is needed to drain the system. V two-pipe system this may be one of the last in the radiator branch, to the lower free inlet of which a drain ball valve is installed. Another option is shown in the following diagram. Shown here is a closed-type one-pipe heating system.

Closed circuit single pipe system heating with a power supply unit for the system

One more important device-, in another way called "safety unit".

What does the heating safety group consist of?

The safety group for the heating system consists of a housing on which three instruments are installed: a pressure gauge, a safety valve and an automatic air vent:

Safety group for heating: from left to right - safety valve, automatic air vent, pressure gauge

Let's consider these devices separately.

Safety valve

The purpose of the safety valve is to protect the heating system from too much pressure.

The safety valve is designed for a certain pressure and when this pressure is exceeded, it works, that is, it releases the excess.

In fact, to compensate for excess pressure in heating system the expansion tank responds: water expands when heated - its surplus is displaced into the expansion tank, which keeps the pressure in the system constant, and the system is intact. In this case, the total amount of heat carrier in the entire heating system remains the same.

But it happens that the expansion tank for some reason did not work. For such a nuisance, a safety valve is installed through which excess water is discharged from the system. So that the water does not flow out to the floor, we attach the tube to the thread on the side and bring this tube into the sewer.

Conclusion: sewage in the boiler room is very desirable.

Where to install the security group?

If the boiler is wall-mounted, then the manufacturers did their best for us: there is already a safety block inside or on the back wall of the boiler.

But for a floor-standing boiler, you need to buy a security group separately and embed it into the system with your own hands. Where? On the supply pipe, as close as possible to the boiler, but not further than 1 ... 1.5 m from the boiler.

The pressure gauge should be located so that its readings are visible without tension, at any visit to the boiler room. The coolant flowing out through the safety valve should also be easily noticeable, because you must be aware of such a phenomenon!

Important! NO valves are installed between the boiler and the safety group!

What are the heating safety groups?

Security blocks come in different configurations, for example, the following:

Safety group for heating

Or prisoners in one building:

Security group, enclosed in one building

Well, many different others can be found on sale, but appearance is not important, since all safety units work in the same way, but you need to choose, as mentioned above, according to the pressure for which the safety valve and pressure gauge are designed.

How to make a security group with your own hands?

Can you make a safety block yourself? Yes. Buy separately a pressure gauge, a safety valve and an air vent and connect them to each other using tees, adapters, squeegees, etc.

The housing for the safety group can even be soldered from scraps of polypropylene pipes and fittings, which is much cheaper than a factory product, which contains a lot of brass.

You just need to understand that a safety group made of polypropylene can only be installed in low temperature systems heating (warm floor, not radiators!). Why? If the coolant for some reason heats up above 95 degrees, then the polypropylene will collapse with all the ensuing (not only consequences, but also boiling water!)

This will make your life calm during the heating season.

safety group for heating, safety block