Types of gas masks
The main purpose of most types of gas masks is to protect the respiratory tract. According to the methods of protection and types of structures, two types of gas masks are distinguished: filtering and insulating.
Filtering gas mask GP
It is used with a filter box and is designed to protect the respiratory system using mechanical filters or chemical reactions. Those who put on such a gas mask continue to inhale the surrounding air mixture in a purified form.
Such masks provide protection only for a limited time and only against a specified type of harmful elements. This is because the filter box is not universal and, moreover, will require replacement after its resource has expired. Filter life may vary. Their action can last for a few minutes, or even a day, and depends on the degree of damage to the habitat.
Isolating gas mask (IP)
This unit is equipped with a compressor box. An insulating gas mask is designed to protect the respiratory organs in an oxygen deficiency environment. A distinctive feature of an insulating gas mask from a filtering one is that its owner can receive a respiratory mixture not from the external environment.
This type of gas mask is divided into two types depending on the source of the breathing mixture. The first type is a self-contained breathing apparatus, the owner of which has its own compressor box with a compressed air cylinder. The second type is a hose-type gas mask (respirator) that receives airflow from an external source, for example, from a compressed air pipeline.
In addition, combined versions of insulating gas masks are often used. For example, when the main air flow comes through the hose, but in case of emergency there is also a self-contained air cylinder.
Composition and device
The design and use of a self-contained breathing bag self-contained gas mask is more complex than simpler filter devices.
Components of the device:
A rubber mask protects the skin, eyes, respiratory organs, and the head of a person from poisoning with poisons and other toxic substances.
- Survey unit made of plastic. Allows a person to see the environment in conditions of infection without damaging the mucous membrane of the eyes with poisons.
- A connecting tube conducts exhaled air into the cartridge for purification and restoration.
- The regenerative cartridge purifies the exhaled air, transforming it into breathable air.
- The start unit is used to supply the first doses of oxygen and start the air regeneration process.
- The breathing bag is used as a storage for purified and enriched air.
- Frame supporting the air-converting cartridge.
- The negotiation device allows you to talk without the threat of infection in an emergency.
Device and characteristics
The main nuances are determined by GOST 2014. It should be noted that firefighters (including those intended for evacuation), medical, aviation, industrial and children's breathing devices are covered by different standards. GOST 2014 says that a civilian gas mask must provide protection against:
- chemical warfare agents;
- industrial emissions;
- radionuclides;
- hazardous substances produced in large quantities;
- dangerous biological factors.
Operating temperatures range from –40 to +40 degrees Celsius. Operation with air humidity over 98% will be abnormal.And also it is not required to ensure normal vital activity when the oxygen concentration drops below 17%. Civilian gas masks are divided into a face block and a combined filter, which must have a full connection. If parts are connected using a thread, a unified standard size in accordance with GOST 8762 should be used.
If a particular model is designed for increased protection against a particular substance or class of substances, additional functional cartridges can be developed for it. Standardized:
- time spent in toxic environments of a certain concentration (minimum);
- the level of resistance to air flow;
- the degree of speech intelligibility (must be at least 80%);
- total weight;
- pressure fluctuations under masks when testing in a rarefied atmosphere;
- suction coefficients of standardized oil mist;
- transparency of the optical system;
- viewing angle;
- field of view area;
- open flame resistance.
In an advanced version, the design includes:
- mask;
- a box for filtering air with the absorption of toxins;
- spectacle block;
- interphone and drinking apparatus;
- inhalation and exhalation nodes;
- fastening system;
- films for the prevention of fogging.
