A fire in a multi-storey building is always an extremely dangerous incident, due to which hundreds and even thousands of people can lose their lives. After all, with large areas of ignition and high smoke content of a high-rise building, it becomes very difficult to extinguish a fire. In addition, if there are a large number of people in the room, there may be serious problems with evacuation and, as a result, a large number of human casu alties. Based on the above reasons, the smoke exhaust system is one of the most important communications in modern multi-storey buildings. This system copes with its task due to the fact that it contains fire-retarding valves. We will talk about how they are arranged, what their types are, and what their principle of operation is in this article.
How the smoke exhaust system works
Smoke removal occurs thanks to specially mounted system channels, which are placed in the middle of the ventilation structure. The smoke removal process consists of several stages. The first is the weathering of the smoky stream. And the second is pumping clean air intothe middle of the building. This makes it possible to safely and quickly evacuate people during a fire. Fire retardant valves help to cope with this task. They will be discussed further.
What are fire dampers
The fire-retardant "bug" valve is a metal box made of high-alloy or galvanized metal, equipped with a special sensor and mechanism. It is installed in air ducts and openings that cross fire barriers and walls. A fire damper drive is located in the immediate vicinity. These valves are able to prevent the spread of fires through ventilation systems. They are highly fire resistant.
Types of valves that delay the spread of fire
Fire-retardant valves are divided into several types. Among them, valves of normally open type (NO), normally closed (NC) can be distinguished.
Normally open dampers are designed for duct installation. They are constantly open. As soon as a fire signal is received, the valve closes automatically. Thus, a smoke screen is established, and the fire can no longer freely spread through the ventilation channels. After the fire has been completely extinguished, the fire dampers will open and fresh air will begin to enter the room. Thus, it happensventilation of the room after the elimination of the source of ignition.
Normally closed fire dampers are installed directly in the ventilation lines. Their task is to prevent the spread of smoke flow. Every day they are closed and open only on a signal from the fire station. Such valves are designed to vent smoke from a burning room.
Installation of fire dampers is always carried out exclusively by specialists. Incorrect connection can lead to the destruction of the entire system.
The purpose of the valves to delay the fire
Fire dampers can be used for different needs, so they have slightly different designs. By type of execution, three main ones can be distinguished.
1. General industrial valves are the most common type. They are installed in residential areas, shops, offices, shopping centers and enterprises that do not have an increased risk of explosions.
2. Explosion-proof valves are distinguished by the fact that they are able to withstand explosions. They are distinguished by the presence of "non-sparking pairs of materials." Such dampers are designed for installation in rooms where explosive mixtures of all groups and categories are available. They also differ from other types by the presence of an additional flameproof shell of the valve actuator. They are not equipped with electromagnets and thermal locking devices that have a redundant effect.
3. valves,intended for use in nuclear power plants. They have a number of differences in their structure. They are not used in everyday life and industry.
Fire damper kit
The fire-retardant "bug" valve is completed with the following components:
- electric drive, which has a built-in return spring;
- electric drive type "closed/open";
- an electromagnet with a return spring;
- an electromagnet with a return spring, having a fusible insert (oriented to a temperature of 72 ° C).
How to operate fire dampers
Fire dampers are generally controlled in two ways.
The first one is the manual mode. In this case, the command by which the valve closes or, on the contrary, opens, is given from the fire department. This type is good in that it does not require complex and expensive automatic equipment. But in terms of security, it is noticeably inferior to the following.
The second type is the automatic mode. This method eliminates the impact of the human factor, and therefore is considered more reliable. The valve only starts when it receives a signal from the automatic control system.
Importance of a fire suppression system
The presence of high-quality and correctly installed fire dampers in the room is a mandatory requirement that applies to the fire safety system of anycivil or industrial facility. It is also a guarantee of people's safety. Fire dampers are just one of the components of a complete fire extinguishing system, which must be completed and installed in accordance with all norms and requirements for fire safety in premises.
In addition to a competent and high-quality installation, the system must undergo regular technical inspections. According to their results, all breakdowns should be immediately eliminated. Human lives depend on it.
