Alphanumeric designations of gas pipelines. Alphanumeric designations of gas pipelines Combustible materials of group g1 g4

There are several popular types of polystyrene-based foam, these are foamed polystyrene foam PSB-S and PSB, as well as extruded polystyrene foam EPS. They have almost identical properties, but there are some differences. PSB-S foam plastic is produced from foaming polystyrene, which contains fire retardants - these are substances that slow down the processes of ignition and combustion. Polystyrene foam with fire retardants does not support the combustion process and does not spread fire. The self-burning time is no more than 4 seconds and when the fire source is removed, the PSB-S foam plastic stops burning - it goes out, which is why it is called self-extinguishing and is designated by the letter “C”. It has a flammability group of G1.

PSB foam cannot be distinguished from PSB-S foam; it has the same appearance, color and characteristics, but does not contain fire retardants; this is reflected in its flammability group - G3 or G4. This foam supports combustion and does not go out within 4 seconds. Extruded polystyrene EPS foam has the same flammability group, which during the combustion process forms melt drops that continue to burn.

It is also worth noting that not all products are made from mineral wool non-flammable, there are a number of mineral wool products that have flammability groups G1 and G2, this is due to the fact that the connecting elements between the mineral wool fibers are flammable polymer materials, which support the combustion process.

Construction materials according to DBN V.1.1-7-2002 “Fire safety of construction projects” are divided into non-flammable (NG) and flammable (G1-G4). The flammability group is determined according to DSTU B V.2.7-19-95 “Building materials. Combustibility testing methods" and there are four groups:

• G1 (low flammability);
• G2 (moderate flammability);
• G3 (medium flammability);
• G4 (high flammability).

To determine the flammability group, tests are carried out in the laboratory. A fire flame produced using gas burner, act on the sample for 10 minutes. The temperature of the flue gases, the degree of damage to the sample along its length and weight, and the duration of independent combustion are measured. Depending on the obtained indicators, the material is assigned to one or another flammability group.

For materials of flammability group G1-G3, the formation of melt drops that will burn during testing is not allowed.

The flammability of polystyrene foam depends on the source raw material and is marked according to DSTU B.V.2.7-8-94 “Polystyrene foam boards. TU", like PSB or PSB-S. In the first case, foam plastic marked PSB does not contain a fire retardant and will belong to the group of increased flammability (G3 and G4). This type of material is used mainly in the production of packaging, this is packaging household appliances and food products, and is called “packaging”. PSB foam plastic without the addition of a fire retardant cannot be used as a building material!!!

In the second case, foam plastic marked PSB-S (self-extinguishing) belongs to the groups of low, moderate or medium flammability. This type of material is used in construction as thermal insulation, production decorative elements or structural parts (sandwich panels, permanent formwork and so on). When using PSB-S foam in the system " wet facade"(according to DSTU B.V.2.6-36-2008 “Structures of external walls with facade thermal insulation and cladding with plasters”), the slabs must belong to flammability groups G1 or G2, polystyrene materials with other flammability cannot be used in this system!!! It is also impossible to use PSB-S slabs in the “ventilated facade” system, since according to the requirements of DSTU B.V.2.6-35-2008 “Structures of external walls with facade thermal insulation and cladding with industrial elements with a ventilated air gap” in this system there must be non-flammable thermal insulation.

Often on the thermal insulation market you can find PSB foam without fire retardant additives, which is passed off as construction PSB-S. “Packaging foam,” as you know, is strictly forbidden to be used in construction. Why is it on the market? The answer is simple, it is more accessible and costs less than high-quality polystyrene foam. There is only one way out of this situation, to purchase polystyrene foam from trusted manufacturers who value the quality and loyalty of their customers, such as the manufacturer PE Eurobud, which constantly monitors the quality of its products. The products of the PE Eurobud company belong to the flammability group - G1 and are confirmed by the protocol of the Fire Safety Research Center.

Conclusion: Polystyrene foam that can be used in construction should be labeled as PSB-S and belong to the flammability group G1 or G2. Such foam plastic is allowed to be used in construction by both Ukrainian and European standards, in different systems thermal insulation. It should also be noted that the EU fire safety policy is based on the “end use” conditions of the insulating material or structure. That is, the necessary fire safety characteristics are determined for everything structural element building. In this connection, it is always recommended to cover polystyrene foam with a protective or sealed coating, which cannot be ignored during proper construction. Based on this, we can conclude that products made of polystyrene foam with flammability type (G1, G2) do not pose a fire hazard if they are installed in accordance with building codes and depending on their purpose.

Flammability group materials are determined according to GOST 30244-94 "Building materials. Combustibility test methods", which corresponds to the International Standard ISO 1182-80 "Fire tests - Building materials - Non-combastibility test". Materials, depending on the values ​​of flammability parameters determined according to this GOST, are divided into non-flammable (NG) and flammable (G).

Materials include to non-flammable at the following values ​​of flammability parameters:

1. temperature increase in the furnace is no more than 50°C;
2. sample weight loss no more than 50%;
3. Duration of stable flame combustion is no more than 10 seconds.

Materials that do not satisfy at least one of the specified parameter values ​​are classified as flammable.

Combustible materials, depending on the values ​​of flammability parameters, are divided into four flammability groups in accordance with Table 1.

Table 1. Flammability groups of materials.

Material flammability group determined according to GOST 30402-96 "Building materials. Flammability test method", which corresponds international standard ISO 5657-86.

In this test, the surface of the sample is exposed to radiant heat flux and flame from an ignition source. In this case, the surface heat flux density (SHFD) is measured, that is, the amount of radiant heat flux affecting a unit surface area of ​​the sample. Ultimately, the Critical Surface Heat Flux Density (CSHDD) is determined - minimum value surface heat flux density (SDHD), at which stable flame combustion of a sample occurs after exposure to a flame.

Depending on the KPPTP values, materials are divided into three flammability groups indicated in Table 2.

Table 2. Flammability groups of materials.

To classify materials according to smoke generation abilities use the value of the smoke generation coefficient, which is determined according to GOST 12.1.044.

Smoke generation coefficient is an indicator characterizing the optical density of smoke generated during flaming combustion or thermal-oxidative destruction (smoldering) of a certain amount of solid substance (material) under special test conditions.

Depending on the relative smoke density, materials are divided into three groups:
D1- with low smoke-generating ability - smoke generation coefficient up to 50 m²/kg inclusive;
D 2- with moderate smoke-generating ability - smoke generation coefficient from 50 to 500 m²/kg inclusive;
D3- with high smoke-forming ability - smoke generation coefficient over 500 m²/kg.

Toxicity Group combustion products building materials determined according to GOST 12.1.044. The combustion products of the material sample are sent to a special chamber where experimental animals (mice) are located. Depending on the condition of the experimental animals after exposure to combustion products (including death), the materials are divided into four groups:
T1- little dangerous;
T2- moderately dangerous;
T3- highly dangerous;
T4- extremely dangerous.

The fire safety of construction projects directly depends on the type of materials used. During the construction of structures, the latter are tested for flammability and behavior under conditions of occurrence. emergency situations, in particular, fire. The intensity, nature of the flow and the immediate outcome of the incident are determined by the totality of the properties of the raw materials that were used in the construction of the building. According to DBN V 1.1-7.2016 of Ukraine, materials are conventionally divided into flammable substances and non-flammable substances, this and a more detailed classification will be discussed further.

The main test method: how is the flammability of a material determined?

To understand the process of testing substances, it is necessary to understand the terminology. There are the following classes of flammability of materials:

• non-flammable;
• difficult to burn;
• flammable.

To determine which of them a substance belongs to, testing is carried out using a single method in the laboratory. All types of materials are subject to inspection: facing, finishing and others (including liquids, paint coatings). The process looks like this: samples in the amount of 12 pieces for each unit of the test substance are kept for three days in a room at room temperature. During this period, potentially combustible and non-combustible materials are weighed until they reach a constant mass. By “room” we mean a structure consisting of three parts: a chamber, air supply and exhaust systems.

Flammability classes of building materials: explanation of terminology

So, we have figured out how the flammability of building materials is checked; all that remains is to give a clear definition of the classification. Let's take a closer look:

• Flammable. It is obvious that such substances actively burn on their own under certain conditions. environment and continue to blaze with and/or without a flame source. It is this class that is divided into 4 groups of flammability of building materials, which we will consider in more detail below.
• Difficult to burn. This category includes compounds that can actively burn only if there is a supply of oxygen and ignition occurs at outdoors. That is, in the absence of a fire source, the material will stop burning.
• Non-combustible building materials. Do not ignite in air, however, they can enter into chemical reactions with each other, oxidizing agents, water. Based on this, individual materials pose a potential fire hazard. According to state rules and regulations, the flammability group of NG substances is determined by two types of studies, based on the results of which a number is assigned (1 or 2).

Let's take a closer look at the last type of substances - non-flammable, as well as the tests that are carried out on them. In 1 case we are talking about studies in which the temperature in a special furnace increases by no more than 50 degrees, and the mass of the sample is reduced to a maximum of 50%, heat is released - up to 2.0 MJ / kg. There is no combustion process. The second group includes materials with similar indicators, with the exception of the heat generated (here it is no more than 3 MJ/kg), but there is still a flame, and it burns for up to 20 seconds.

Combustibility groups of materials according to DBN V.1.1-7-2016: main criteria

To classify raw materials used in the construction of buildings and various structures, the following characteristics are analyzed:

• the temperature of the gases that are released along with the smoke;
• reduction in material mass;
• degree of volume reduction;
• duration of flame preservation without a combustion source.

The flammability groups of materials and substances are obviously designated by the letter G. They are in turn divided into four classes. Let's look at each of them in more detail:

1. G1 flammability is characteristic of substances and materials that cannot burn without a flame source. However, under the right conditions, they are capable of releasing gases that form smoke. The temperature of the latter is no more than 135 degrees. In this case, the damage along the length caused by the flame does not exceed 65%, and complete destruction - a maximum of 20% of the total volume.
2. Group G2 includes building materials that, after eliminating the source of flame, continue to burn for no more than 30 seconds. The maximum temperature of the flue gases is 235 degrees, damage along the length is up to 85%, and weight loss is up to half of the total.
3. Flammability group G3 is assigned to those materials that are capable of maintaining the combustion process for five minutes after the flame source is eliminated. The temperature of the gases that are released can reach 450 degrees Celsius. Length and weight are reduced in the same way as in the case of raw materials from the G2 class.
4. Highly flammable materials are classified as group G4. In all respects they are identical to substances from the previous group, but with one caveat: flue gases are released at temperatures of 450 degrees, or even more.

Confirming the flammability class: specifics of the process

Non-combustible and combustible materials are examined separately in laboratory conditions and in open space. Since samples can consist of several layers, each of them is tested.

First, researchers/laboratory technicians check and calibrate the equipment, warm it up, and then secure the test objects in special holders. The latter are located inside the oven, which, in turn, is equipped with recorders. The sample is kept in the heating chamber until it reaches a balanced temperature. That is, when the range of fluctuations stabilizes at around 2 degrees Celsius.

To obtain the correct result and assign the material flammability class G1/2/3/4, it is necessary to cool the sample in a desiccator and then measure its mass and length. According to the data obtained, the test substance is classified into the current group.

Raw materials of different aggregate states in the context of flammability should be considered separately:

1. Liquids. They are considered flammable if they can ignite at a certain temperature. If external source there is no fire, and the liquid is not able to support the process, then it is considered low-flammability. Non-flammable substances under normal conditions with a full supply of oxygen, they do not ignite at all. Those that flare up even with a slight increase in air temperature are considered especially dangerous. For example, ether and acetone ignite already at 28 degrees Celsius.
2. Solid. In the construction industry, materials cannot be used on site without testing. The safest are those that belong to the non-flammable group or group G1.
3. Gaseous. The maximum concentration of gas contained in a mixture with air is estimated, at which from the point of ignition the flame can spread as far as desired. long distance. If such a value cannot be derived, the gaseous material is classified as non-flammable.

Why is it necessary to determine the flammability group of a material?

When assessing fire hazard, not only the flammability group G1/G2/G3/G4 is taken into account, but also a number of other properties of materials. Namely:

1. Flammability (difficult, moderate and flammable).
2. Speed ​​of fire spread (non-spreading, weakly, moderately and strongly spreading).
3. Smoke generation intensity (low, moderate and high).
4. The degree of toxicity of gases released during combustion (low-, moderate- and high-hazardous, extremely dangerous).

Based on the analysis of the totality of all five properties, a class is formed fire danger the buildings. The scope of use of a particular material is determined by its flammability and its group. Properly selected raw materials and compliance technological processes do not only finished design safe for operation, but also minimizes the risk of emergency situations at a construction site.

Summing up: when is testing of the flammability of building materials carried out?

For most buildings, construction by definition includes obtaining various permits, as well as restoration, expansion, technical re-equipment of the building, repairs and other activities. Also, sometimes a fire inspection is required for a certain type of building, this question regulated by law. The latter includes the assessment of building materials for flammability, combustibility, etc. That is, a change functional purpose design is also a sufficient reason to examine the raw materials, and, if necessary, assign the structure a different fire hazard class.

Please note that the CP for a structure is determined initially, and only then building materials are selected for it. But there are pitfalls here too: the same, for example, composite cassettes cannot be used for cladding different buildings- shopping center (possible), schools or medical institution- it is forbidden. In addition, it is prohibited to decorate evacuation passages and many other public areas with materials of flammability groups 3 and 4, while in private low-rise construction they are used everywhere (MDF panels, etc., created on the basis of organic raw materials). These and other subtleties are prescribed in Ukrainian legislation; you just need to study them or entrust this matter to specialists.

Penolex - a variety thermal insulation materials, which is extruded polystyrene foam.
Most people, when choosing suitable insulation for their home, are guided by the various characteristics of the material. Many are interested in low price, some prefer ease of installation, and only a small part think about environmental safety and fire resistance. What characteristics does penoplex have? Is it combustible or absolutely non-flammable? It’s strange, but there are a lot of opinions about this indicator, so it’s worth taking a closer look at the fire safety of penoplex.

What flammability class does penoplex belong to?

When studying the flammable properties of extruded polystyrene foam, it is necessary to take into account the fact that manufacturers produce different brands of this material. They all have different characteristics, which is why there are different opinions about their flammability.

All building materials are divided into several groups according to flammability:

• G1 – materials are slightly flammable.
• G2 – moderately flammable materials.
• G3 – materials with normal flammability.
• G4 – materials with highly flammable properties.
• NG are absolutely non-flammable materials.

Most sellers prefer to remain silent about the vapor barrier properties of polystyrene foam, since their main task is to sell it in any way. Some even claim that only they can buy non-flammable extruded polystyrene foam. As soon as you hear such statements, leave immediately. Today, there is simply no non-flammable penoplex, but it can be classified as a slightly flammable building material.

Is penoplex dangerous in a fire?

We need to figure out whether extruded polystyrene foam poses a fire hazard. Previously, all types of penoplex belonged to the group of materials with normal flammability or highly flammable properties. Such materials, in addition to their flammability, emitted dangerous gases, which made penoplex especially dangerous in case of fire. But recently, manufacturers switched to the production technology of G1 class penoplex, that is, low flammability. The insulation obtained such properties thanks to the addition of a fire retardant, a substance that can increase the resistance of building materials to open fire. According to experts, the new penoplex does not emit harmful substances, like wood, it emits only carbon dioxide and carbon dioxide.
But even with such statements from manufacturers, buyers are not inclined to believe them. This is due to the fact that, according to government regulations, extruded polystyrene foam cannot be slightly flammable. And all its types belong to group G3 or G4.

Is penoplex flammable or not?

Official manufacturers do not provide any information about absolute non-flammability. There is only mention of an independent study, according to which penoplex began to be classified as class G1. But there are no such records in official government documents. This is what causes controversy; some consumers are sure that the independent examination was interested in the result, so the statement that penoplex does not emit harmful substances is simply absurd.
But based on the statements of both sides, we can conclude that opponents of the non-flammability of polystyrene are simply unfamiliar with the properties of the fire retardant. Of course, such substances will not be able to prevent fire, but will not allow the material to burn out. How to explain this? It's simple. Under the direct influence of a flame, penoplex will light up, but as soon as the fire stops affecting it, it immediately goes out. It is based on these characteristics that polystyrene foam is called non-flammable, since in itself it can cause a fire.
If we evaluate the statements that penoplex emits no more harmful substances than wood, it looks controversial. Since extruded polystyrene foam is a synthetic material, in addition to carbon monoxide, it emits other chemical compounds, which can cause pulmonary edema, severe poisoning and even suffocation in humans.

Can penoplex be called non-flammable?

To summarize the above information, is penoplex non-flammable and is it safe in case of fire?

• Classic extruded polystyrene foam belongs to the groups of highly and normally flammable materials.
• Only by adding fire retardants does penoplex become slightly flammable.
• It cannot be called non-flammable, since even despite its high fire resistance, it can still be ignited under the direct influence of fire.
• Substances that are released during the combustion of penoplex are dangerous to humans.

Considering all the characteristics, experts advise buying low-flammable penoplex. It differs significantly in price, but its performance characteristics are worth it. The main difference is the density of the insulation blocks; treated with anti-friction, penoplex is denser. The building materials market offers insulation from various manufacturers, which makes it possible to choose the best option.

How to choose the right penoplex?

Proper insulation should be aimed at maximizing heat retention inside the room, while at the same time not exposing it to fire hazard. In order to purchase the quality product you need, you need to contact only experienced manufacturers who have a good reputation in the building materials market.
After choosing a manufacturer, you need to familiarize yourself with all accompanying documents, where all state regulations and compliance with them will be indicated. You can also trust the conclusions of independent expert institutions, which are often available from manufacturers. Nowadays, you can find construction companies who can conduct a small experiment, after which you will be convinced of the fire resistance of the material.

Conclusion

The main thing you need to remember is that buying insulation treated with anti-flight does not guarantee complete fire safety. To preserve all its fire-fighting properties, you need to take into account necessary instructions on installation and processing. Most often, extruded polystyrene foam is used to insulate floors, basements and foundations. It is strictly prohibited to use it to insulate walls and facades. It is precisely because of the fire hazard that this insulation cannot be used in all areas of construction. Fortunately, manufacturers are constantly working to improve it, using various technologies production and treatment of insulation with protective substances. Soon, penoplex will have everything necessary qualities for widespread use in the field of insulation of residential and industrial premises.

The flammability group is a conditional characteristic of a certain material, reflecting its ability to burn. In relation to drywall, it is determined by conducting a special flammability test, the conditions of which are regulated by GOST 3024-94. This test is also carried out for other finishing materials, and based on the results of how the material behaves on test bench, it is assigned one of three flammability groups: G1, G2, G3 or G4.

Is drywall flammable or non-flammable?

All building materials are divided into two main groups: non-combustible (NG) and combustible (G). To qualify as non-combustible, the material must meet a number of requirements that are imposed on it during the testing process. A sheet of drywall is placed in an oven heated to a temperature of about 750 ° C and kept there for 30 minutes. During this time, the sample is monitored and a number of parameters are recorded. Non-combustible material must:

• increase the oven temperature by no more than 50 °C
• give a steady flame for no more than 10 s
• decrease in weight by no more than 50%

Plasterboard sheets do not meet these requirements and are therefore classified in group G (flammable).

Drywall flammability group

Combustible building materials also have their own classification and are divided into four flammability groups: G1, G2, G3 and G4. The table below illustrates the standards that a material must meet to receive one of the four groups.

The specified parameters refer to samples that have passed the test using Method II, according to GOST 3024-94. This method involves placing the sample in a combustion chamber, in which it is exposed to a flame on one side for 10 minutes so that the temperature in the furnace ranges from 100 to 350 ° C, depending on the distance from the bottom edge of the sample.

In this case, the following characteristics are measured:

• Flue gas temperature
• The time it takes for the flue gases to reach their highest temperature
• Weight of the test sample before and after the test
• Dimensions of damaged surface
• Does the flame spread to that part of the samples that is not heated?
• Duration of burning or smoldering both during heating and after completion of exposure
• Time it takes for the flame to spread to the entire surface
• Does the material burn through?
• Is the material melting?
• Visual change appearance sample

Having collected and analyzed all the above indicators obtained in laboratory conditions, the material is assigned to one or another flammability group. Based on the figures that were recorded when testing a gypsum board sheet with dimensions of 1000x190x12.5 mm according to Method ll described above, it was found that the flammability group of plasterboard is G1. According to this group, the temperature of its flue gases does not exceed 135 °C, the degree of damage along the length of the sample is no more than 65%, damage by weight is no more than 20%, and the self-combustion time is zero.

Video

Watch a visual process of testing drywall for flammability in the following video:

Fire hazard class

Standard partitions on a metal frame made of plasterboard sheets with an average density of 670 kg/m³ and a thickness of 12.5 mm according to GOST 30403-96 belong to fire hazard class K0 (45). This means that when an unloaded material was exposed to fire for 45 minutes, no vertical or horizontal damage was recorded in it, and there was no combustion or smoke formation.

At the same time, in practice, load bearing capacity of a single-layer plasterboard partition is lost after just 20 minutes of fire exposure to the surface of the material. In addition, it should be taken into account that Fire safety The specific plasterboard partition will depend on its design. Is it installed on metal carcass or on a wooden sheathing, whether there is a layer of insulation inside and whether it is flammable.

In addition to fire hazard and flammability, such characteristics as toxicity group of combustion products, smoke-generating ability group and flammability group are also applicable to plasterboard.

In terms of toxicity of combustion products, gypsum plasterboard sheets are classified as low-hazard (T1). The smoke-forming ability of a material characterizes it as having a low smoke-forming ability (D1) with a smoke generation coefficient of no more than 50 m²/kg (smoke optical density). For comparison, wood during smoldering has a value of this coefficient equal to 345 m²/kg. Flammability group for plasterboard B2 - moderately flammable materials.