Categorization of premises for explosive and fire hazard: TKP. Categories of premises for explosion and fire hazard: examples

In modern production, a large volume of combustible and explosive materials is processed and used. Existing production lines are focused on high speed operations. An increase in productivity leads to an increase to critical limits of parameters such as temperature, pressure, and the ratio of oxidizing agent to combustible components. In this regard, the potential threat of explosions and fires is increasing, the destructive force of which causes enormous material damage, leading to injuries and death of employees of enterprises. As the analysis of major accidents shows, their consequences extend not only to the facilities of the enterprises themselves, but also to nearby housing estates. Assessing the cause-effect relationships of technical disasters allows you to take the necessary preventive measures not only during the operation of production systems, but also in the development of terms of reference for designing, drawing up diagrams and plans, as well as during construction. As part of this activity, the categorization of premises according to explosion and fire hazard is applied. Consider this classification in detail.

General information

Calculation of the category of explosion and fire hazard of the premises allows you to objectively establish the conditional level of the threat of a technical catastrophe. Based on the obtained parameters, the development and justification of organizational and technical solutions are carried out. They, in turn, ensure optimal exploitation of the areas within the limits of acceptable risk.

Normative base

To preserve the life, health of people, property of legal entities, the municipality and the state from fires, Federal Law No. 123 was approved. Its provisions determine the key areas of technical regulation in this area. The regulatory act establishes the basic safety requirements for facilities, including constructions, structures, premises, buildings, fire-technical and general-purpose products. Specifies the provisions of the specified Federal Law. In accordance with it, the premises are categorized by explosive and fire hazard. SP 12. 13130. 2009 formulates a methodology for classifying areas. It depends on the amount of materials and substances that are or are used within them. Specialists also take into account the features of technological processes. The Code of Practice defines the category of explosive and fire hazard of storage facilities and industries. Other areas cannot be divided.

Classification criteria

Categories of premises for explosive and fire hazard are determined in accordance with the type of combustible materials and substances contained in them, their quantity and properties. In addition, space-planning decisions of areas and characteristics of technological processes that are carried out within them are taken into account. The properties of materials and substances are established on the basis of the results obtained during testing, or calculations by standard methods, taking into account state indicators (temperature, pressure and others). It is allowed to use reference, officially published information on the properties of materials and substances. It is also allowed to apply indicators for mixtures of materials and substances for the most dangerous component.

Separation principles

Categories of premises for explosive and fire hazard are established taking into account accident factors, properties of the final and initial product, equipment characteristics, etc. The following principles are the basis of the existing separation technique:

1. Recognition of the possibility of a normative (specific) power of an accident.
2. Accounting for the amount of materials and substances that contribute to the formation of dust or vapor-air mixtures that create a threat.
3. Taking into account the properties of raw materials used in production.

When categorizing premises according to explosive and fire hazard, specialists should take the most unfavorable variant of the disaster or the period of normal activity of the technological system and the elements that make up it. These principles formed the basis of the requirements that must be observed during the classification.

Categorization of premises for explosion and fire hazard: SP

To assess and compare the level of threat and degree of protection, five groups and three classes are defined. The table shows their characteristics.

In accordance with the indicated groups, the premises are categorized by explosive and fire hazard. The labels presented in the article indicate the software class of the object. They are an integral requirement of current regulatory documents.

Note

As a quantitative measure for dusty and vapor-air mixtures, an excess pressure of 5 kPa is used. This indicator does not threaten the life of staff. Categories of premises for explosive and fire hazard B1-B4 are determined using the energy parameter. It is expressed in unit load (MJ / m2).

Categorization of premises for explosive and fire hazard (GOST)

When classifying, it is necessary to take into account the physicochemical characteristics of materials and substances and their parameters:

1. Combustibility group.
2. The maximum pressure during the explosion and its rate of rise.
3. Conditions for spontaneous combustion (thermal).
4. Concentration levels of fire spread.
5. Burnout rate.
6. Auto-ignition temperature.
7. Oxygen index.
8. Flash point.
9. Ignition energy (minimum).
10. Temperature limit for flame spread.
11. The ability to burn and explode on contact with other compounds, oxygen, water.
12. Flame temperature.
13. Smoke coefficient.
14. The toxicity parameters of products formed during the combustion of polymeric substances and materials.
15. Standard rate of spread of fire.
16. Minimum explosive oxygen concentration.
17. Fire Spread Index.
18. Flash point
19. Phlegmatizing minimum concentration of phlegmatizer.

At the same time, the number of parameters sufficient and necessary to characterize the explosion and fire hazard of materials and substances in the conditions of their processing, production, storage and transportation is set by the developer of technical specifications and GOST. This function can also be performed by the designer of the security system at the facility.

Classification of substances

The categorization of premises for explosive and fire hazard is carried out taking into account the following separation:

1. Gases are substances in which the absolute vapor pressure at temp. 25 deg. equal to or greater than 101.3 kPa.
2. Solid materials have an incandescent (melting) temperature of more than 50 degrees. and not having her at all.
3. Liquids are substances in which the saturated vapor pressure at a temp. 25 deg. and a pressure of 101.3 kPa less than 101.3 kPa.
4. Dusts are dispersed solid materials with a particle size of less than 850 microns.
   

Key factors

The categorization of premises for explosive and fire hazard is carried out taking into account the following conditions:

1. The most adverse consequences of a failure of one device are taken into account.
2. All installation contents enter the room.
3. During the time required for shutdown, a simultaneous leakage of substances from the pressure and suction pipelines.
4. Estimated stop time with a probability of failure of the automatic system is not more than 10-6 per year or provides redundancy of elements. At a higher rate, the automatic shutdown period is 120 seconds, manual installation is 300 seconds.
5. Evaporation occurs from the surface of a spilled combustible liquid from apparatus and tanks with an open mirror and freshly painted planes. Its area is determined at the rate of 1 liter per 1 square. m room. In the absence of reference data on combustible mixtures, the indicator is calculated based on the fact that 1 liter of a liquid containing 70% or less solvents is poured into 0.5 square meters. m
6. The duration of evaporation is taken equal to the period of complete evaporation, but not more than 3600 sec.
7. In the event of a machine malfunction with dust, its mass of particles present in the installation is taken into account. In this case, dust accumulation is adopted in accordance with the conditions of the normal operating mode.
8. The free volume in the room is allowed to be equal to 80% of the full.

Determination methods

How exactly is the categorization of premises for explosive and fire hazard? TKP 474-2013 - Code of Practice, formulates a classification methodology. The distinction is made using deterministic and probabilistic approaches. With the help of the latter, the random nature of emergency situations is taken into account. The probabilistic method allows you to assess the actual level of danger in general and in particular cases. The deterministic approach is based on a quantitative analysis of the recovered potential energy release during technical disasters. It should be noted the peculiarity of the methods that are used in determining the category of premises for explosive and fire hazard. Practical examples indicate that the approaches used characterize the probability of an accident without taking into account the occurrence of the ignition source and the area of ​​consequences.

Technical Code

In accordance with its provisions, a general categorization of premises for explosive and fire hazard is carried out. TCH is not applied in relation to objects, classification of which is carried out according to special rules and norms. Separation carried out in accordance with the code must be used to formulate requirements for ensuring the protection of areas during planning, determining the number of storeys, sizes. compartments, the organization of evacuation of people, the installation of engineering equipment, the adoption of constructive decisions, etc. Requirements should be taken into account in projects for the construction, modernization, reconstruction, technical re-equipment, as well as in the adjustment of technological processes during the use of facilities.

Scope of application

In what cases are the categories of premises determined by explosion and fire hazard? Examples of activities in the framework of which it is necessary to carry out the classification in question can be given as follows:

1. Exploitation.
2. Design.
3. Replacement of equipment.
4. Technology change.
5. Reconstruction.
6. Substitution of production volume.

Stages

First of all, it should be said that not every organization can categorize premises according to explosion and fire hazard. License - the main document authorizing the production of such activities. The work consists of two stages. At the first stage, the necessary information is collected:

1. Dimensions and characteristics of objects.
2. Equipment layout (working drawings).
3. Technical certificate.
4. Technical regulations.
5. Parameters and scheme of the ventilation system.
6. The structure of automatic control of production parameters.
7. Fire extinguishing system diagram.
8. Other material data.

If the work is carried out at the design stage, then the necessary information is taken from technical documents. The second stage is, in fact, the calculation of categories.

Regulatory Features

After checking and establishing the category of premises, requirements are formulated. Protection of facilities is provided in accordance with Gosstandart. It, in particular, prescribes the existence of fire prevention systems (MTP) and fire protection (SDR). In addition, organizational and technical measures (OTM) are provided. Gosstandart also formulates requirements for ways to provide protection with BSC and SDR systems, which involve the categorization of premises for explosive and fire hazard. NPB 105.03 (regulatory rules) determine the requirements for the protection of AOP and AUPT (automatic ignition detection and extinguishing systems). These requirements are mandatory for organizations and enterprises, regardless of departmental affiliation and form of ownership, as well as individuals. Type AUPT, type of extinguishing agents, method of eliminating fire, type of equipment are installed in accordance with the technological features of the protected objects. In this case, the draft fire protection scheme and the requirements of regulatory documents are taken into account. Areas for engineering installations with powerful processes and other facilities in which combustible materials are not contained can be equipped with AUOP and AUPT. In rooms where there is a fire alarm, it is necessary to install a security system. With the area of ​​the facility subject to AUPT equipment of 40% or more of the total floor size, it is necessary to provide for the installation of this system as a whole throughout the structure. For a building belonging to category B1, S is reduced by 20%. Moreover, the area of ​​the facilities of group B3 is allowed to increase by the same amount.

Conclusion

As practice shows, quite often performers and specialists have problems categorizing buildings and premises. Meanwhile, competent and qualified establishment of an object group is crucial at the stage of design and construction of structures. If the categorization work is carried out correctly, then all technical issues that arise subsequently will be resolved correctly. In accordance with the provisions of the Federal Law No. 69, each leader is required to comply with the requirements of the PB. This means that the company should provide a set of organizational and preventive measures aimed at reducing the likelihood of threats to the safe operation of production facilities, the life and health of employees, and the safety of material and production values. Mistakes made in determining the necessary measures can lead to their redundancy or insufficiency. This, in turn, will lead to inefficiency of material costs for fire prevention measures.