Security group is designed to provide and control the required pressure in the heating or hot water supply system and reset it when it goes beyond the maximum limit.
The security group consists of: safety valve, which dumps part of the water (coolant) with its excess, an air vent, and a pressure gauge. All these elements can be installed in the system both separately and assembled in one housing.
Safety valve (valve overpressure) - is a valve in which the closing stem is pressed by a spring. The spring stiffness is selected at the factory by setting the valve to a certain pressure (1.5, 3, 6 bar, etc.). Safety valves must be installed in all systems where expansion of water (heat carrier) due to heating is possible. In the house, such systems are - heating and hot water supply system (boiler indirect heating or water heater). If the pressure in the system rises higher than the rating of the safety valve - the valve spring will no longer be able to hold water, it will compress and open the valve - the pressure will be released, but simply the "excess" coolant will be discharged into the side outlet of the valve.
In order not to get burned when the valve is suddenly opened or not to spoil the repair in the room, a drain pipe is screwed to the side outlet and sent to the sewer or drainage tank.
Do not think that when triggered, the overpressure valve releases a lot of water - in ordinary private houses, in order for the pressure to drop from 3 to 1 bar, it is necessary to release about one glass of water, and sometimes less.
In order for the safety group to bleed air from the system, it must be installed in the upper part of the pipes suitable for the boiler or boiler, that is, the air vent protects the boiler or boiler from airing. Protection of radiators or other high points of the system is provided by other auto air vents or Mayevsky cranes.
Shut-off valves must not be installed between the boiler and the safety group!
When choosing a boiler safety group, it is necessary to clarify what power it is designed for. For powerful boilers - safety valves with a large flow area (3/4 or 1 inch thread) are used in the safety group.
Safety valves are selected based on the nominal working pressure in the system. Consider the nominal pressures of the main engineering systems and the necessary safety valves for them.
1 bar \u003d 1.0197 kgf / cm2 \u003d 0.98692 atm.
In most cases, the boiler safety group is not set correctly, which leads to the removal of the boiler from the guarantee.
First, let's explain what a security group is, why it is needed and what it consists of. The safety group consists of a pressure gauge, an air vent and a safety valve. Now let's explain the purpose of each element of the group:
From all of the above, it follows that the safety group protects the heating system from excessive pressure and airing.
During the installation of a closed heating system, it is necessary to make sure that in the event of failure of any element, it can be replaced without any special difficulties, or repair work, without draining the entire system and without doing laborious procedures. Therefore, for these purposes, Ball Valves(cut-off). Let's say your radiator is leaking. We simply turn off the two shut-off valves that are installed before and after it, and remove the radiator, while the entire system continues to function, which is not unimportant when the temperature outside is below zero degrees. Therefore, if there were no these taps and bypass (in this case the bypass will be a branch from the main line to the radiator), then the entire system would have to be drained, and this would take a lot of time and labor. And most importantly, during the repair work, the heating system will not work, and this is fraught. Therefore, shut-off valves are placed on any heating element to avoid these difficulties. That is, if we install a radiator, we install shut-off valves; put circulation pump- we put shut-off cranes; put membrane tank- put shut-off valves, and so on.
It is set to supply. Due to ignorance or illiteracy, many, when installing a safety group, put a shut-off valve between the boiler and the safety group (Fig. 1),
or directly to the security group (Fig. 2),
arguing that in the event of a boiler failure, it will be possible to replace it or carry out repair work. In both cases, the installation was not carried out correctly and, in the event of a boiler failure, service centres they will refuse you warranty repairs, arguing that the boiler is not installed correctly: such an arrangement of the valve makes it possible for the system to overheat and the boiler to fail if the shut-off valve is blocked by workers, third parties or children.
It is necessary to install the boiler safety group so that the shut-off valve is behind it (Fig. 3)
This arrangement is absolutely correct and indicates that the installation was carried out by qualified specialists. In this case, no one will be able to refuse you a warranty repair.
Users of individual heating systems are obliged to independently ensure that heating equipment functioned as safely as possible. For this purpose, a safety group must be installed in the heating system, as it will prevent excessive pressure and minimize the risk of airing, so that all appliances will be fully operational. Such a group is a set of devices that ensure trouble-free operation of the network and control of the pressure of the working fluid.
More details about what a security group is, what elements it consists of and how it is installed, will be discussed in today's article.
For the convenience of users, information about manufacturers is given in the form of a small table.
Table 1. Manufacturer of safety groups for heating
|
Name |
Available Models |
Description |
Average market value, in rubles |
|
|
They are produced in two modifications - Professional (I have round shape) Standart (can be of two types - square and brass). |
All models are designed to protect heating system closed type, and also to install an expansion tank. |
From 1308 to 1422 |
|
|
It is produced in only one modification, namely Fado-1. |
Brass safety group in the heating system, which can be used with a heat generator, a tank or a "warm floor" 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. |
Connection of the lower type, the nominal pressure indicator 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) |
|
|
These groups are available in five versions, but all of them are designed to protect the heating boiler. There are such models of Watts blocks on the market: |
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 case). Installed above the heat generator, in a vertical position. |
From 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
Any security group is metal body containing the following devices:
We will deal with the structure and purpose of each of the elements.
Such a valve is intended 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 (the indicator) is exceeded, it trips and everything superfluous is reset. In principle, in heating, pressure is compensated using an expansion tank: when the liquid heats up, its excess enters the tank, so that the pressure in the network remains constant, and the system itself does not suffer because of this. Tellingly, the total volume of the working fluid remains 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 discharged into the sewer. And from this we can draw another conclusion: the boiler room must necessarily have a sewerage system.
Note! In this case, in no case should antifreeze be poured into the sewer system (if it is used as a coolant).
At the top of the valve there is a handle (often red), through which the device is checked for operation. 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 released, the valve is working properly. If the flow of water continues, then you need to open / close the valve a few more times - usually after that everything returns to normal.
If the water does not want to stay in the valve, it should be replaced, and as soon as possible. Fluid can also leak if the valve is not tight enough in the seat. It is worth noting that fuses are made with the expectation of various pressure indicators, 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, you need a valve for 3 atmospheres.
But what if the safety group in the heating system 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 already at home with your own hands (more on this later).
The main purpose of the pressure gauge is to regulate the pressure in the line. They, as well as the fuses written above, can be designed for different pressure indicators 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 be designed for a maximum of 4 atmospheres.
There are two arrows on the device itself - black (it is also working) and red (required for control). The second arrow must be set manually to the required mark (usually 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 during the operation "went" further than the red one, then the pressure has increased too much.
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 go. In fact, this is another kind of Mayevsky crane that can operate on the machine. It is not necessary to twist or unscrew it, because the air is vented automatically. When emergency This device is truly indispensable. For example, the temperature controller may suddenly stop working, causing the working fluid in the heat generator to boil. And at this time, air can be released, which, with a 100% 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 will be carried out - air - removal.
Note! A prerequisite the normal functioning of the security group is its competent installation. The slightest mistake during installation deprives the use of the group of any meaning, and it may simply not work in case of a critical situation.
How this group works
Now suppose that for some reason 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 increase. Then the safety valve works: the spring in it is no longer able to hold the working fluid, it is compressed, due to which the valve opens and the pressure is finally released.
How does all this happen?
Note! In order to avoid accidental burns in the event of a sudden operation of the valve and the discharge of excess working fluid, a special hose or tube is connected to the outlet, which must be brought into the sewer system.
The configuration of security blocks, as noted above, can be very diverse. There is, for example, such an option.
Or here is another option in which all the elements are enclosed in a single case.
A few more options.
There are many other options for performing a security group on sale, but external indicators in this case do not matter, since the principle of operation for all of them is the same. One or another model should be chosen, we repeat, according to the pressure indicator for which the pressure gauge and safety valve are designed.
Now, having dealt with the main types of groups, we will get acquainted with popular manufacturers and the approximate cost of such products.
In the case of a wall-mounted heating boiler, you can not 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 floor-standing boilers, blocks should be purchased separately and installed with your own hands. Where exactly? On the supply pipe, as close as possible 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 its readings are clearly visible. It is also necessary that the working fluid that flows out of the safety valve is clearly visible, which should also be known before the start of installation work.
First you need to briefly talk about shut-off ball valves (later you will learn 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 is leaking. 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, and this is extremely important if it is cold enough outside. In the absence of such valves, all the working fluid will have to be drained from the line. This will require 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 short instruction, from which you will know in what order the block should be installed.
Step 1. The safety group should be placed on the supply pipe, no further than 100-150 centimeters from the heating boiler.
Step 2 Not having the required knowledge, when installing this device, many people put shut-off valves between it and the heat generator, or, alternatively, directly on the group itself. Their explanation is as follows: if the boiler fails, it can be easily fixed or replaced. Below are two options incorrect installation shut-off valves.
In each of the examples, the taps were installed incorrectly, and if the heat generator fails, then its seller will refuse your guarantee, since the device was not installed as it should. With this kind of arrangement of taps, the risk of overheating of the system increases, which can lead to boiler failure.
Step 3 With proper installation, the 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
Many are interested in whether it is possible to make such a group with your own hands? It is possible, but for this you need to separately purchase each of the elements, and then connect them using adapters, tees, and so on. You can weld the body of the block from pieces of fittings and pipes made of polypropylene - this will cost much less than the "store" version made of brass.
At the same time, do not forget that the polypropylene safety group can only be installed in those lines where the temperature of the working fluid is low (for example, in "warm floor" systems), but in no case in batteries! This is because if the liquid is heated to 95 degrees, this will lead to the destruction of polypropylene, and the consequences of this can be the most unpredictable.
Video - Security Group
One more important device-, otherwise called the "security block".
The safety group for the heating system consists of a housing on which three devices 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 take a look at these devices one by one.
The task 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 dumps the excess.
In fact, the expansion tank is responsible for compensating for excess pressure in the heating system: water expands when heated - its excess is forced into the expansion tank, which keeps the pressure in the system constant, and the system intact. At the same time, the total amount of coolant 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 placed through which excess water will be dropped 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: sewerage in the boiler room is very desirable.
If the boiler is wall-mounted, then the manufacturers did their best for us: the safety unit is inside or on back wall boiler is already there.
But for a floor-standing boiler, you need to buy a security group separately and insert it into the system with your own hands. Where? On the supply pipe, as close as possible to the boiler, but no further than 1 ... 1.5 m from the boiler.
The pressure gauge should be located so that its readings can be seen without tension, during any visit to the boiler room. The coolant flowing through the safety valve should also be easily visible, because this phenomenon must be known!
Important! No valves are placed between the boiler and the safety group!
Security blocks come in different configurations, for example, these:
Safety group for heating
Or enclosed in one body:
Security group enclosed in one body
Well, many different others can be found on sale, but appearance is not important, because all safety blocks work 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.
Is it possible to 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, spurs, etc.
The body for the security group can even be soldered from scraps of polypropylene pipes and fittings, which will cost much less than a factory product, which has a lot of brass.
You just need to understand that a polypropylene safety group can only be placed in low temperature systems heating (warm floor, not radiators!). Why? If for some reason the coolant heats up above 95 degrees, then polypropylene will collapse with all the consequences (not only consequences, but also boiling water!)
This one will make your life calm in the heating season.
safety group for heating, safety block
The security group, or, as it is also called, the security unit for a water heating system, is very important element. If an emergency situation arises (for example, the expansion tank), then the heating system will sharp increase pressure, which may cause a pipe to burst or the boiler to break.
To prevent this, in such cases, the security group is included in the work. It automatically releases excess pressure, thereby preventing it from exceeding the established norm.
Any security group consists of four main parts:
Important!
Since the boiler is the most sensitive element of the system to pressure increase, the safety valve is purchased with the same response threshold, which is the maximum allowable during the operation of the boiler equipment itself (this figure is indicated in the boiler passport).
In addition, the membrane valve is mounted so that in the event of an emergency, it relieves exactly the pressure that has arisen inside the boiler.
Sometimes all these parts are mounted separately on the supply pipe, but always so that the safety valve is above the boiler equipment. However, more often, an integral safety group is still placed in the heating system. So much cheaper, faster and more convenient.
Note!
By appearance security blocks may vary, however, the principle of operation is the same for all.
Therefore, do not fall into confusion if you are offered a choice of devices that are not similar to those shown in the photographs given in the article.
Let's imagine this situation: for some reason, the expansion (membrane) tank did not balance those expansions that are necessary for the stable operation of the entire heating system. The pressure inside the system builds up.
And then the safety valve is sure to work: the valve spring can no longer hold the coolant, it contracts, opens the valve, and pressure is released.
How is the pressure released?
Advice!
In order to avoid burns during the sudden opening of the valve and the release of excess coolant, a drain pipe must be connected to its side outlet and directed to the sewer drain.
As a rule, in, such a group is already installed, and you do not have to purchase it additionally. But if you have a floor-standing boiler (especially for domestic models), then there is probably no security block in it. You have to embed it into the heating system with your own hands. How to do it?
First of all, let's discuss such a moment as shut-off ball valves (why we touched on this issue, you will understand a little later). During the installation of the heating system, it is necessary to make sure that in the event of a breakdown of any of its elements, it can be repaired or replaced without much difficulty, without draining. For this, shut-off ball valves are installed.
Suppose you have a leaky radiator in your house. You simply turn off the two shut-off valves located before and after the radiator, and remove the radiator itself. Thus, the entire heating system continues to work, and this is very important, especially if it is below zero outside the window.
But if there were no such taps, then all the coolant would have to be drained. It will take a lot of time, effort, and most importantly, while the repair work is going on, the heating system will not function.
Advice!
It is advisable to install shut-off valves on any element of the heating system: be it a radiator, a circulation pump, an expansion tank, and so on.
Now let's talk directly about the security group.
Here small instruction, telling about which block location will be correct:
However, in both cases, the installation was not carried out correctly, and if the boiler breaks down, service centers will refuse warranty repairs, referring to the fact that the equipment was not installed according to the rules. Such an arrangement of shut-off valves increases the likelihood of overheating of the system and, as a result, the breakdown of the boiler when they are closed.
Advice!
When choosing a security block, pay attention to Watts products.
Devices of this manufacturer are the most popular among Russian citizens, since they have optimal ratio price/quality/durability.
Equipment such as security groups allows you to live and sleep peacefully, without worrying about a sudden failure of the heating system. In the presented video in this article you will find Additional information on this topic.
