Air insulating apparatus for firefighters AIR-98MI and PTS "PROFI" are designed for individual protection of the respiratory system and human eyes from the harmful effects of unsuitable for breathing toxic and smoky gas environment when extinguishing fires in buildings, structures and industrial facilities for various purposesv temperature rangeenvironment from minus 40 to60 ° C and stay in an environment with a temperature of 200 ° C for 60 s.

BREATHING APPARATUS FOR FIRE AIR-98MI

The main technical characteristics of the AIR-98MI apparatus and its modifications are given in table.

The apparatus is made according to an open circuit with an exhalation into the atmosphere.

When the valve (s) 1 is opened, high-pressure air flows from the cylinder (s) 2 into the manifold 3 (if any) and the filter 4 of the reducer 5, into the high-pressure cavity A and after reduction into the reduced-pressure cavity B. The reducer maintains a constant reduced pressure. pressure in cavity B regardless of the change in inlet pressure. In the event of a malfunction of the reducer and an increase in the reduced pressure, the safety valve 6 is triggered. From the cavity B of the reducer, air flows through the hose 7 into the lung demand valve 11 or into the adapter 8 (if available) and then through the hose 10 into the lung demand valve 11. It is connected through valve 9 rescue device.

The lung demand valve maintains a predetermined excess pressure in cavity D. When inhaling, air from cavity D of the lung demand valve is supplied to cavity B of mask 13, air blowing over glass 14, prevents it from fogging. Further, through the inhalation valves 15, air enters the cavity D for breathing.

Schematic diagram of the breathing apparatus AIR-98 MI

To control the air supply in the cylinder, air from the high-pressure cavity A flows through the high-pressure capillary tube 18 to the manometer 19, and from the low-pressure cavity B through the hose 20 to the whistle 21 of the signaling device 22.

When the working supply of air in the cylinder is exhausted, a whistle is turned on, warning with an audible signal that an immediate exit to a safe area is required.

RESPIRATORY APPARATUS PTS "PROFI"

The devices are produced in various versions, differing in the following features:

A complete set of various types and number of cylinders;

Complete set with various types of front parts;

Possibility of completing with a rescue device.

The apparatus is an insulating reservoir breathing apparatus with compressed air with a working pressure of 29.4 MPa and overpressure under the face. The device is equipped with a panoramic mask PTS "Obzor" TU 4854-019-38996367-2002 or "Panorama Nova Standart" No. R54450.

The device operates in an open breathing pattern with exhalation into the atmosphere and works as follows: when the valve (s) 1 is opened, high pressure air flows from the cylinder (s) 2 into the manifold 3 (if any) and the filter 4 of the reducer 5, into the high pressure A and after reduction into the cavity of the reduced pressure B. The reducer maintains a constant reduced pressure in the cavity B, regardless of the pressure change at the inlet.

In the event of a reducer malfunction and an increase in the reduced pressure, the safety valve 6 is triggered.

From cavity B of the reducer, air flows through the hose 7 into the lung machine 11 and into the adapter 8 and then through the hose 10 into the lung machine 11. A rescue device is connected through the valve 9.

The lung demand valve maintains a predetermined overpressure in cavity D. When inhaling, air from cavity D of the lung demand valve is supplied to the cavity B of the front part 13. Air blowing over glass 14 prevents it from fogging. Further, through the inhalation valves 15, air enters the cavity D for breathing.

Schematic diagram of the breathing apparatus PTS "Profi"

On exhalation, the inhalation valves close, preventing exhaled air from entering the glass. To exhale air into the atmosphere, the exhalation valve 16 is opened, located in the valve box 17. The exhalation valve with a spring allows maintaining a predetermined excess pressure in the undermask space.

To control the air supply in the cylinder, air from the high-pressure cavity A flows through the high-pressure capillary tube 18 to the manometer 19, and from the low-pressure cavity B through the hose 20 to the whistle 21 of the signaling device 22. When the working air supply in the cylinder is exhausted, the whistle is turned on, warning with a sound signal that only a reserve supply of air remains in the device.

This labor protection manual has been specially developed for the safe operation of machines with compressed air.

1. GENERAL LABOR PROTECTION REQUIREMENTS

1.1. The operation of personal protective equipment of the respiratory system is a set of measures for the use, maintenance, transportation, maintenance and storage of RPE. Correct operation means compliance with the established regimes of use, deployment in combat crew, storage and maintenance rules for RPE.
1.2. It is prohibited:
- make changes in the design of breathing apparatus that are not provided for by the technical (factory) documentation;
- use breathing apparatus for work underwater.
- use of RPE, the technical condition of which does not ensure the safety of the gas and smoke defender;
- the work of the bases and control posts of the GDZS, the state of which does not meet the requirements of the Labor Protection Rules and the Manual on the Gas and Smoke Protection Service.
1.3. The operation of personal protective equipment for the respiratory system includes:
- Maintenance;
- content;
- placing in a combat crew.
- ensuring the operation of the bases and control posts of the GDZS;
1.4. Maintenance includes: combat check, check No. 1,2,3; cleaning, flushing, adjusting, lubricating, disinfecting; elimination of malfunctions in the scope of current repairs.
1.5. Working check is a type of maintenance of the RPE carried out in order to promptly check the serviceability and correct functioning (action) of units and mechanisms immediately before performing a combat mission to extinguish a fire. It is performed by the owner of the breathing apparatus under the guidance of the commander of the GDZS unit (chief of the guard, squad leader, as intended) before each inclusion in the RPE.
1.6. During a working check of the breathing apparatus, it is necessary:
1.6.1. Check the serviceability of the mask and the reliability of the connection of the lung demand valve:
- check the completeness of the panoramic mask, the integrity of the glass, half-holders (glass mounting rims), the condition of the headband and valve box belts;
- Reliability of connection of the lung demand valve to the panoramic mask.
1.6.2. Check the tightness of the air duct system (for vacuum):
- firmly press the face of the mask to the face;
- take a deep breath from the system;
- if a large resistance is created during inhalation, which does not allow further inhalation and does not decrease within 2-3 seconds, the breathing apparatus is considered airtight.
1.6.3. Check the lung demand valve and expiratory valve:
- first switch off the lung demand valve (with the button);
- open the cylinder valve;
- apply the mask to the face and take 2-3 deep breaths and exhales. At the first inhalation, the machine should turn on and there should be no breathing resistance;
- insert a finger under the mask abturator, make sure there is excess pressure (the characteristic sound of the air flow should be heard);
- hold your breath for a few seconds and make sure that there is no air leakage through the exhalation valve;
- turn off the lung demand valve.
1.6.4. Check the response pressure of the signaling device:
- close the cylinder valve;
- apply a panoramic mask to the face, inhale and slowly pump out the air from under the mask space until the sound signal is triggered, the pressure on the manometer should be in the range of 50-60 atmospheres.
1.6.5. Check the air pressure in the cylinder:
- with the lung demand valve turned off beforehand, open the cylinder valve and check the pressure using the external pressure gauge. The pressure must be at least 260 atm.
1.7. If the apparatus is in good working order, make a report to the commander of the GDZS link in the form: "Gas and smoke protector Ivanov is ready for switching on, pressure 280 atm."
1.8. Check No. 1 is a type of maintenance carried out in order to constantly maintain the RPE in good condition during operation, check the serviceability and correct functioning (action) of the units and mechanisms of the breathing apparatus. It is carried out by the owner of the breathing apparatus under the guidance of the chief of the guard (in the firefighting service - the senior shift on duty):
- immediately before taking up combat duty;
- after check No. 3, disinfection, replacement of air cylinders, fixing the RPE for the gas and smoke protector, as well as at least once a month if the RPE was not used during this time. The check is carried out in order to constantly maintain the RPE in good condition;
- after using a breathing apparatus in a fire (training);
- before carrying out training sessions in clean air and in an environment unsuitable for breathing, if the use of the RPE is provided during free time from guard duty (combat duty).
1.9. The reserve RPE is checked by the squad leader.
1.10. When checking the No. 1 breathing apparatus, it is necessary:
- check the serviceability of the mask. If the mask is fully completed and there is no damage to its elements, it is considered to be in good working order;
- inspect the breathing apparatus, check the reliability of the attachment of the suspension system of the apparatus, the cylinder and the pressure gauge, as well as make sure that there are no mechanical damages of units and parts;
- check the tightness of the high and reduced pressure system, open the cylinder valve, read the air pressure on the pressure gauge and close the cylinder valve. If within one minute the drop in air pressure in the apparatus system does not exceed 10 atmospheres, the apparatus is considered hermetically sealed;
- check the magnitude of the pressure at which the sound signaling device is triggered, close the inlet of the lung demand valve with the palm of your hand; press the central part of the rubber cover (turn on the overpressure mechanism); gently raising your hand, maintaining a slight drop in pressure, slowly release air from the system until the sound signal is triggered; by observing the reading of the pressure gauge, determine the operation of the sound signal. The sound signal is considered serviceable if it is triggered at a pressure of 50 - 60 atmospheres;
- check the tightness of the airway system with the lung demand valve, connect the mask to the lung demand valve; put on a mask, tighten the head straps so that a snug fit with light pressure is felt along the entire obturation strip. With the cylinder valve closed, inhale, if at the same time there is a great resistance that does not allow further inhalation, and does not decrease within 2-3 seconds, the airway system is considered hermetically sealed;
- check the health of the lung demand valve and the exhalation valve, open the cylinder valve to the full by turning the handwheel counterclockwise (if a leak is immediately detected, press the central part of the rubber cover to turn on the overpressure mechanism, and then press the setting lever to turn it on again Repeat these steps 2-3 times, the leak should stop). Take 2-3 deep breaths, if the overpressure mechanism immediately turns on and breathing resistance is not felt, the lung demand valve and the exhalation valve are considered to be in good working order;
- check the serviceability of the additional air supply device, press the button for the additional air supply of the lung governed demand valve. If a characteristic sound of air supply is heard, the device is considered to be in good working order;
- check the serviceability of the gas reducer, checked by external inspection;
- check the air pressure in the cylinder, checked by the pressure gauge. When placed in a combat crew, the pressure in the cylinder must be at least 260 atmospheres.
1.11. If the device is in good working order, an entry is made in the check log # 1.
1.12. Check No. 2 is a type of maintenance carried out within a specified calendar time frame, in full and with a specified frequency, but at least once a year. All RPEs that are in operation and in reserve, as well as those requiring complete disinfection of all assemblies and parts, are subject to inspection. The check is carried out on the basis of the GDZS by the senior foreman (foreman) of the GDZS. In the absence of a full-time senior master (master) of the GDZS, these duties are assigned to another employee 7 of the OFPS, who must have special training in the amount provided for the senior master (master) of the GDZS and the corresponding admission.
1.13. Submission of the RPE for inspection is carried out by divisions of 7 OFPS in accordance with the schedule developed by the senior foreman (foreman) of the GDZS and approved by the head of the gas and smoke protection service. The schedule provides for the sequence of submission of the RPE by months, indicating the serial numbers.
1.14. The results of the inspections are recorded in the inspection log No. 2 and in the registration card for the RPE; a note is also made in the annual inspection schedule.
1.15. Breathing apparatus check No. 2 provides for:
- disassembly, inspection, flushing, cleaning, disinfection, adjustment of units and assembly of the breathing apparatus. These operations are carried out in accordance with the technical description (operating manual) for the breathing apparatus;
- check of panoramic masks (facepieces), a lung demand valve, connectors, a reducer, cylinder valves, rescue and signaling devices (for AIR), an air reserve switch and a charging connection (for ASV);
- repair and replacement of worn parts. Filters, gaskets, valves and all rubber seals and rings are usually replaced;
- equipment of the breathing apparatus after complete assembly, its adjustment and check No. 1.
1.16. Disassembly and assembly of the RPE is carried out on separate tables.
1.17. It is prohibited to use the RPE with the faults identified during the checks for the work of the personnel of the GPS units until these faults are eliminated, which is noted in the log, the form of which is given in the Manual on GDZS.
1.18. Repair of respiratory protective equipment is a complex of works for maintaining and restoring the serviceability of breathing apparatus. Repair consists in eliminating minor faults, restoring operational characteristics by replacing or restoring individual parts and parts of the RPE, in carrying out a complete disassembly, replacement or repair of all faulty components, assembly, comprehensive inspection, adjustment and testing.
1.19. Repair is organized and carried out by senior foremen (foremen) of the GDZS, as a rule, on the basis of the GDZS.
1.20. Self-repair and adjustment of the RPE by gas and smoke protectors are prohibited.
1.21. When a malfunction is detected, the RPE is removed from the combat crew and transferred to the GDZS base.
1.22. Acceptance-change must be recorded in an act indicating the malfunction with two signatures of the dealer and the receiver.
1.23. The results of the repair and subsequent inspection are recorded in the inspection log No. 3 and in the registration card for the RPE.
1.24. Each gazodimozashchitnik bears personal responsibility for the serviceability and quality of service of the RPE assigned to him.
1.25. Maintenance of RPE at bases, control posts of GDZS and fire trucks:
- Serviceable (verified) and faulty RPEs are stored at the GDZS bases separately in the cells of cabinets or racks so as not to damage units and parts.
- Breathing apparatus, breathing apparatus masks for personnel free from guard duty, a reserve of RPE, cylinders are stored at the control posts of the GDZS serviceable, clean and ready for work.
- For transportation of RPE for repairs and for inspection, filling of cylinders, special boxes with cells are used.
- Breathing apparatus are placed on a fire engine in an upright position in specially equipped cells. To protect the RPE from mechanical damage, the bottom and walls of the cells are upholstered with shock-absorbing material.
- At negative ambient temperatures, breathing apparatus masks must be placed in the cockpit of a fire fighting crew.
- The main-purpose fire engine, the combat crew of which is armed with breathing apparatus, is equipped with a reserve breathing apparatus.
- One backup set of air cylinders must be provided for each breathing apparatus taken out in a fire engine.

2. LABOR PROTECTION REQUIREMENTS BEFORE STARTING WORK

2.1. The preparation of the RPE for work is carried out when entering on combat duty on guard (duty shift) and at the place of fire (training).
2.2. Preparing the RPE for work includes:
a) when taking up combat duty:
- obtaining a RPE at the service station of the GDZS;
- Carrying out check No. 1;
- filling out the log of registration of inspections No. 1;
- installation of RPE on a fire engine.
b) at the site of the fire (training):
- putting on the RPE and adjusting its harness;
- carrying out a working check. The flight commander gives the command "GDZS link, gas masks (breathing apparatus) - CHECK!"
- report to the commander of the GDZS link on the oxygen (air) pressure in the cylinder and the readiness to perform the combat mission: “Gas and smoke defender Petrov is ready to be switched on, the pressure is 280 atmospheres!”;
c) after work in the RPE:
- flushing, drying, re-equipment of the RPE;
- Carrying out check No. 1;
- filling out the log of checks No. 1 and the personal card of the gas and smoke defender;
- installation of the RPE on a fire engine or placement at the control post of the GDZS.
2.3. When entering combat duty, the air pressure in the cylinders of breathing apparatus must be at least 25.4 MPa (260 kgf / cm2) for breathing apparatus with a working pressure of 29.4 MPa (300 kgf / cm52).
2.4. Before each inclusion in the breathing apparatus, the GDZS link carries out a working check for one minute in the order and sequence established by the Manual on GDZS.
2.5. It is forbidden to be included in the RPE without carrying out a working check and in the event of any malfunctions.
2.6. The inclusion of personnel in the RPE is carried out at the command of the commander of the GDZS link "GDZS link, turn ON in the devices!" in the following sequence:
- take off the helmet and clamp it between the knees;
- put on a mask;
- put on a shoulder bag with a rescue device (for devices of the AIR type);
- put on a helmet.
2.7. When carrying out work with the use of the RPE for extinguishing fires, classes, be guided by the labor protection requirements set out in the instructions for labor protection when working in the RPE.

3. REQUIREMENTS FOR LABOR PROTECTION DURING WORK

3.1. Before entering the smoke-filled zone, the GDZS link secures the guide cable to the structure next to the security post, and then moves to the fire in a "bundle".
3.2. For every three links operating in a fire, a backup link is organized at the checkpoint, the GDZS security post.
3.3. When conducting hostilities to extinguish a fire in an environment unsuitable for breathing, as part of the GDZS unit, gas and smoke defenders must:
- obey the commander of the GDZS link, know the combat mission of the GDZS link (squad) and complete it;
- know the location of the security post and checkpoint;
- strictly observe the route of movement of the GDZS link and the rules of work in the RPE, follow the orders given by the commander of the GDZS link;
- not to leave the GDZS link without the permission of the commander of the GDZS link;
- follow the changes in the situation on the route of movement, pay attention to the state of building structures both during movement and at the place of work, remember the path traveled;
- follow the pressure gauge on the air pressure in the RPE cylinder;
- do not use, unnecessarily, the emergency valve (bypass);
- turn on and off the RPE at the command of the commander of the GDZS link;
- report to the commander of the GDZS link on changes in the situation, detected malfunctions in the RPE or the appearance of poor health (headache, sour taste in the mouth, difficulty breathing) and act on his instructions;
- open doors with caution, protecting from possible emission of flames and gases by the door panel;
- to enter the premises where there are energized installations, devices and vessels under high pressure, explosive, poisonous and other hazardous substances, only after preliminary consultation and receiving instructions from the specialists of the enterprise.
3.4. To ensure the safety of gas and smoke defenders when working in breathing apparatus, the flight commander must:
- to know the combat mission of your link (squad) of the GDZS, to outline an action plan for its implementation and the route of movement, to bring this, as well as information about the possible danger, to the personnel of the GDZS link;
- supervise the work of the GDZS link, fulfilling the requirements of the rules of work in the RPE and safety requirements;
- indicate to the personnel the location of the checkpoint and security post;
- check the presence and serviceability of the required minimum equipment for the gas and smoke defender, necessary to complete the assigned combat mission;
- conduct a combat check of the assigned RPE and control its implementation by the personnel of the link and the correctness of inclusion in the RPE;
- check before entering an environment unsuitable for breathing the air pressure in the cylinders of the subordinates and inform the guard at the security post the lowest air pressure value;
- check the completeness and correctness of the relevant records made by the guards at the security post;
- inform the personnel of the GDZS link when approaching the fire site, the control air pressure, at which it is necessary to return to the security post.
- to provide the necessary assistance to persons in cases of threat to their life and health;
- ensure compliance with the rules of work in insulating gas masks;
- maintain constant communication with the security post, report to the RTP or NBU on the situation and actions of the GDZS link;
- know and be able to carry out first aid techniques to victims;
- alternate the hard work of gas and smoke defenders of the GDZS link with rest periods, correctly dose the load, achieving even deep breathing;
- monitor the well-being of the personnel, the correct use of equipment and weapons, monitor the consumption of oxygen (air) according to the readings of the pressure gauge;
- report on malfunctions or other unfavorable circumstances for the GDZS link to the security post and make decisions on ensuring the safety of the link personnel;
- bring the link to fresh air in its entirety;
- when leaving an environment unsuitable for breathing, determine the place of shutdown from the RPE and give the command to shutdown.
3.5. The flight commander is obliged to monitor the well-being of the gas and smoke defenders, in case of deterioration of health (dizziness, knocking in the temples, nausea, etc.) must report this to the security post and bring the entire flight to fresh air.
3.6. Breathing in the apparatus should be deep and even. If breathing has changed (intermittent, shallow), it is necessary to suspend work and restore breathing by deep breaths until breathing becomes normal.
3.7. Do not remove or pull back on the glass wiper in an unbreathable environment.
3.8. During work, each gas and smoke defender must follow the indication of the external pressure gauge and report to the flight commander about the air pressure in the cylinders.
3.9. When moving to the source of the fire (place of work) and returning back, the first is the commander of the GDZS link, and the most experienced gas and smoke defender (appointed by the commander of the link) follows.
3.10. The GDZS link must return from an unbreathable environment in its entirety.
3.11. The advancement of the GDZS link in the premises is carried out along the main walls, memorizing the route, in compliance with precautionary measures, including those due to the operational and tactical characteristics of the fire object.
3.12. When working in the RPE, it is necessary to protect it from direct contact with an open flame, shock and damage, do not remove the mask or pull it off to wipe the glasses, do not turn off, even for a short time. Shutdown from the RPE is carried out at the command of the commander of the GDZS link.
3.13. It is forbidden for the links of the GDZS to use elevators when working on a fire, with the exception of elevators with the "Transportation of fire departments" operating mode in accordance with GOST 22011.
3.14. In order to ensure safe movement, the GDZS link can use fire hoses, an intercom wire.
3.15. When working in conditions of limited visibility (strong smoke), the commander of the GDZS link in front is obliged to tap the ceiling structure with a crowbar.
3.16. When opening doorways, the personnel of the GDZS link must be outside the doorway and use the door leaf to protect against a possible emission of flame.
3.17. When working in rooms filled with explosive vapors and gases, the personnel of the GDZS unit should be shod in rubber boots, do not use flashlight switches. When moving to the source of the fire (place of work) and back, as well as in the process of work, all precautions against sparks must be observed, including when tapping the structures of the premises.
3.18. When leaving an environment unsuitable for breathing into fresh air, gas and smoke defenders may take off their masks only at the command of the flight commander.
3.19. When working in breathing apparatus, it is necessary:
- use breathing apparatus with overpressure under a mask in environments with hazardous chemicals;
- when the main supply of air is exhausted (for ASV-2), turn on the air reserve, for which, move the reserve switch handle from the "P" position to the "O" position and, as part of the link, leave the environment unsuitable for breathing;
- when the sound signal is triggered (for an AIR-type apparatus), report to the flight commander and leave the environment unsuitable for breathing as part of the flight;
- use, if necessary, the rescue device included in the set of the breathing apparatus (type AIR).

4. REQUIREMENTS FOR LABOR PROTECTION IN EMERGENCY SITUATIONS

4.1. In case of deterioration of health (dizziness, knocking in the temples, nausea, etc.), the gas and smoke defender is obliged to report this to the flight commander. The flight commander, having received such a message, is obliged to report this by means of communication to the security post and to bring the flight in full strength into fresh air.
4.2. In case of termination of communication with the GDZS link working in an environment unsuitable for breathing, as well as upon receiving a message from the workers about an accident or poor health of the gas and smoke defender, the RTP (NBU) is obliged to send a backup link of the GDZS to help the victims, as well as take other possible measures to finding and providing assistance to the injured, taking them to fresh air and providing them with medical assistance.
4.3. When assisting gas and smoke defenders directly in an environment unsuitable for breathing, it is necessary to check the presence of air in the cylinder, the condition of the breathing hoses, use a bypass to supply additional air under the victim's mask, in extreme cases, switch his mask with a lung demand valve to a breathing apparatus (type AIR) of another gas and smoke protector. Take measures to remove the link and the victim to fresh air.
4.4. In the event of a malfunction of the apparatus (malfunction), the gas and smoke defender is obliged to report this to the flight commander, who is obliged to immediately bring the entire flight to fresh air.

5. LABOR PROTECTION REQUIREMENTS AT THE END OF WORK

5.1. At the end of work in an environment unsuitable for breathing, the commander of the GDZS link takes the personnel out into the fresh air.
5.2. The personnel of the GDZS link is turned off from the breathing apparatus at the command of the flight commander, performs an external examination of the technical condition of the breathing apparatus units, masks, then puts the breathing apparatus and masks into the fire truck at their location.
5.3. The flight commander reports to the RTP (NUTP) on the available comments on the work of gas and smoke defenders in an environment unsuitable for breathing, on malfunctions in the operation of breathing apparatus, on the course of extinguishing a fire.
5.4. Upon arrival at the unit, the personnel of the gas and smoke protection service, under the leadership of the chief of the guard (squad leader), checks the serviceability of the breathing apparatus units, masks, cleans, rinsing, drying, disinfection, replacing the used cylinder with a new one, performs check No. 1 and puts the apparatus in combat crew. The results of the checks are recorded in the corresponding logs. Work in the RPE is filled out in the personal card of the gas and smoke defender.
5.5. When malfunctions are detected, the RPE is removed from the combat crew and transferred to the GDZS base.
5.6. Self-repair and adjustment of the RPE by gas and smoke protectors are prohibited.
5.7. Used air cylinders are handed over to the unit's GDZS base for subsequent filling with air.
5.8. After finishing work, wash your hands and face thoroughly with warm water and soap or take a shower.
5.9. Rules and procedure for cleaning and disinfecting breathing apparatus
5.9.1. Cleaning, adjustment, disinfection of the RPE is carried out:
- after de-preservation;
- when conducting inspection No. 2;
- as prescribed by a doctor in connection with the identification of an infectious disease;
- after using the face part of the breathing apparatus by another person and a rescue device for him after each use;
- when putting in the reserve the facial parts of the breathing apparatus;
5.9.2. When cleaning the breathing apparatus, it is carried out:
- incomplete disassembly;
- rinsing with warm water and drying of parts and assemblies;
- assembly and reloading.
5.9.3. When disinfecting the breathing apparatus, the following is carried out:
- incomplete disassembly;
- washing parts and assemblies with warm water;
- wiping the inside of the mask with a disinfectant solution, rinsing and drying it in a drying cabinet at a temperature of 40-50 ° C;
- flushing the lung demand valve with ethyl alcohol and blowing it with heated air. The rescue device of the apparatus is also disinfected after each use.
Note. The order of incomplete disassembly of gas masks (breathing apparatus) is determined by the factory operating instructions.
5.9.4. The following solutions are used for disinfection of RPE: rectified ethyl alcohol;
- solution (6%) of hydrogen peroxide;
- a solution (1%) of chloramine;
- solution (8%) boric acid;
- a fresh solution (0.5%) of potassium permanganate.
5.9.5. After cleaning and disinfection, check No. 2 is carried out.
5.9.6. It is unacceptable to use organic solvents (gasoline, kerosene, acetone) for disinfection.
5.10. At the end of work in an environment unsuitable for breathing, the commander of the GDZS link takes the personnel out into the fresh air.
5.11. After the completion of work in the zone of chemical and radiation contamination, work is carried out on degassing (decontamination) of RPE, SZO, and gas and smoke defenders are required to undergo sanitization, final dosimetric control, and medical examination.
5.12. The personnel of the GDZS link turns off their breathing apparatus at the command of the flight commander, performs an external examination of the technical condition of the breathing apparatus units, masks, then puts the breathing apparatus and masks into the fire truck at their location.
5.13. The flight commander reports to the RTP (NBU) on the available comments on the work of gas and smoke defenders in an environment unsuitable for breathing, on malfunctions in the operation of breathing apparatus, on the course of extinguishing a fire.
5.14. Upon arrival at the unit, the personnel of the gas and smoke protection service, under the leadership of the chief of the guard (squad commander), checks the serviceability of the units of the breathing apparatus, masks, cleans, rinsing, drying, disinfecting, replacing the used cylinder with a new one, performing checks and putting the apparatus in combat crew. The results of the checks are recorded in the corresponding logs. Work in the RPE is filled out in the personal card of the gas and smoke defender.
5.15. When malfunctions are detected, the RPE is removed from the calculation and transferred to the GDZS base.
5.16. Self-repair and adjustment of the RPE by gas and smoke protectors are prohibited.
5.17. Used air cylinders are handed over to the unit's GDZS base for subsequent filling with air.
5.18. After finishing work, wash your hands and face thoroughly with warm water and soap or take a shower.

We express our gratitude to Nikolay for providing this instruction! =)

The apparatus (Fig. 3.23) includes: a harness 1, a cylinder with a valve 2, a reducer 3, a hose with a lung machine 4, a panoramic mask 5, a capillary with a signal device 6, an adapter 7, a rescue device 8.

Rice. 3.23 ... General device of the breathing apparatus PTS "PROFI":

1- suspension system; 2- cylinder with valve; 3- reducer; 4- a hose with a lung machine; 5- panoramic mask; 6- capillary with signaling device; 7- adapter; 8- rescue device

Suspension system(Fig. 3.24) serves to fasten systems and units of the apparatus on it and consists of a plastic back 1, a system of belts: shoulder 2, end 3, fastened to the back with buckles 4, belt 5 with a quick-release adjustable buckle.

Lodgment 6 serves as a support for the balloon. The balloon is fixed with a balloon belt 7 with a special buckle.

Rice. 3.24. Suspension system of the breathing apparatus PTS "PROFI":

1- plastic back; 2- shoulder straps; 3- end belts;

4- buckles; 5- waist belt; 6- lodgment; 7- balloon belt with a special buckle

Balloon designed to store a working supply of compressed air. Steel and metal-composite cylinders can be used depending on the model of the apparatus.

A tapered thread is cut in the neck of the cylinder, along which a shut-off valve is screwed into the cylinder. On the cylindrical part of the cylinder, the inscription "AIR 29.4 MPa" is applied (Fig. 3.25).

Rice. 3.25. Compressed air storage cylinder

Cylinder valve(Fig. 3.26) consists of a body 1, a tube 2, a valve 3 with an insert, a cracker 4, a spindle 5, a stuffing box nut 6, a handwheel 7, a spring 8, a nut 9 and a plug 10.

The tightness of the valve is provided by washers 11 and 12. Washers 12 and 13 reduce friction between the spindle shoulder, the end of the handwheel and the ends of the gland nut when the handwheel rotates.

Rice. 3.26 ... Cylinder valve:

1- building; 2- tube; 3- valve with insert; 4- biscuit; 5- spindle; 6- stuffing box nut; 7- handwheel; 8- spring; 9- nut; 10- plug; 11, 12, 13- washers

The tightness of the valve at the junction with the cylinder is ensured by fluoroplastic sealing material (FUM-2).

When the handwheel rotates clockwise, the valve, moving along the thread in the valve body, is pressed against the seat by the insert and closes the channel through which air flows from the cylinder to the reducer. When the handwheel is turned counterclockwise, the valve moves away from the seat and opens the channel.

The principle of operation of the device PTS "PROFI"

The device operates in an open breathing pattern (Fig. 3.27) with exhalation into the atmosphere and works as follows:

Rice. 3.27. Schematic diagram of the device PTS "PROFI":

1- valve (valves); 2- balloon (balloons); 3- collector; 4- filter; 5- reducer; 6- safety valve; 7- hose; 8- adapter; 9- valve; 10- pulmonary demand valve; 11- mask; 12- glass; 13- inhalation valves; 14- exhalation valve; 15-valve box; 16- high pressure capillary tube; 17- manometer; 18- hose; 19- whistle; 20 - signaling device; A - high pressure cavity; B - reduced pressure cavity; B - the cavity of the mask; G - breathing cavity; D- cavity of the lung valve

when the valve (s) 1 is opened, high pressure air flows from the cylinder (s) 2 into the manifold 3 (if any) and the filter 4 of the reducer 5, into the high pressure cavity A and after reduction into the reduced pressure cavity B. The reducer maintains a constant reduced pressure pressure in cavity B regardless of the change in inlet pressure.

In the event of a reducer malfunction and an increase in the reduced pressure, the safety valve 6 is triggered.

From cavity B of the reducer, air flows through the hose 7 into the lung machine 10 or into the adapter 8 (if available) and then through the hose 7 into the lung machine 10. The rescue device 21 is connected through valve 9.

The lung demand valve maintains a predetermined excess pressure in cavity D. When inhaling, air from cavity D of the lung demand valve is supplied to cavity B of mask 11. Air blowing over glass 12 prevents it from fogging. Further, through the inhalation valves 13, air enters the cavity D for breathing.

On exhalation, the inhalation valves close, preventing exhaled air from entering the glass. To exhale air into the atmosphere, an exhalation valve 14 is opened, located in the valve box 15. The exhalation valve with a spring allows maintaining a predetermined excess pressure in the undermask space.

To control the air supply in the cylinder, air from the high-pressure cavity A flows through the high-pressure capillary tube 16 into the manometer 17, and from the low-pressure cavity B through the hose 18 to the whistle 19 of the signaling device 20. When the working air supply in the cylinder is exhausted, the whistle is turned on, warning with a sound signal of the need to immediately exit to a safe area.

Purpose, device and principle of operation of the gearbox of the device PTS "PROFI"

Reducer(Figure 3.28) is designed to convert high (primary) air pressure in the cylinder in the range of 29.4-1.0 MPa to constant low (secondary) pressure in the range of 0.7-0.85 MPa. A reverse acting piston reducer with a balanced pressure reducing valve allows the secondary pressure to be stabilized when the primary pressure varies over a wide range.

Rice. 3.28. Scheme of the gearbox of the PTS "PROFI" apparatus:

1- building; 2- eyelet; 3- insert; 4, 5- sealing rings; 6- building; 7- saddle; 8- pressure reducing valve; 9- nut; 10- washer; 11- piston; 12- rubber sealing ring; 13, 14 - springs; 15- adjusting nut; 16- locking screw; 17- body cladding; 18- fitting; 19- sealing ring; 20- screw for capillary connection; 21- fitting for connecting an adapter or a hose; 22- fitting; 23- clutch; 24- filter; 25- screw; 26, 27- o-rings

The gearbox consists of a housing 1 with an eyelet 2 for attaching the gearbox to the back, insert 3 with sealing rings 4 and 5, housing b with a seat 7, a pressure reducing valve 8, on which piston 11 with a rubber sealing ring 12 is fixed with a nut 9 and a washer 10 , springs 13 and 14, adjusting nut 15 and locking screw 16.

A lining 17 is put on the gearbox housing to prevent contamination. The gearbox housing has a fitting 18 with a sealing ring 19 and a screw 20 for connecting a capillary, and a fitting 21 for connecting an adapter or a hose.

A fitting 22 with a clutch 23 is screwed into the gearbox housing for connection to the cylinder valve. A filter 24 is installed in the fitting, fixed with a screw 25. The tightness of the connection between the fitting and the body is ensured by the O-ring 26. The tightness of the connection between the valve and the gearbox is ensured by the O-ring 27.

The gearbox design provides safety valve, (Fig. 3.29.) which consists of a valve seat 28, valve 29, spring 30, guide 31 and lock nut 32. The valve seat is screwed into the piston of the reducer. The tightness of the connection is ensured by the sealing ring 33.

In the absence of pressure in the reducer, the piston is in the end position under the action of the springs, while the pressure reducing valve is open.

When the cylinder valve is open, high-pressure air enters the reducer chamber and creates a pressure under the piston, the value of which depends on the degree of compression of the springs. In this case, the piston moves together with the pressure reducing valve, compressing the springs until an equilibrium is established between the air pressure on the piston and the spring compression force, and the gap between the seat and the pressure reducing valve is closed.

When inhaling, the pressure under the piston decreases, the piston with a pressure reducing valve moves under the action of springs, creating a gap between the seat and the valve, providing air flow under the piston and further into the lung governed demand valve. By turning the nut 15, the value of the reduced pressure is adjusted. During normal operation of the gearbox, the safety valve 29 is pressed against the valve seat 28 by the force of the spring 30.

Rice. 3.29. Reducer safety valve:

28- valve seat; 29- valve; 30- spring; 31- guide; 32- lock nut; 33- o-ring

When the reduced pressure rises above the set value, the valve, overcoming the resistance of the spring, moves away from the seat, and the air from the reducer cavity is released into the atmosphere. By rotating the guide 31, the response pressure of the safety valve is adjusted.

The front part of the Obzor PTS

The front part is designed to protect the respiratory system and eyes from the effects of a toxic and smoky environment and the connection of the human respiratory tract with a lung valve (Fig. 3.30).

Rice. 3.30. Front part "Review":

1- building; 2- glass; 3- half-holder; 4- screws; 5- nuts; 6- intercom; 7- clamp; 8-valve box with a socket for a plug connection with a lung demand valve; 9- clamp; 10- screw; 11- spring; 12 - button; 13- exhalation valve; 14- hard disk; 15- overpressure spring; 16- cover; 17- screws; 18- headband; 19 - frontal strap; 20 - two temporal straps; 21 - two occipital straps; 22, 23- buckles; 24- sub-mask; 25 - inhalation valves; 26 - bracket; 27- nut; 28 - washer; 29- neck strap

The front part of the Obzor PTS consists of a body 1 with glass 2, secured by means of half-holders 3 with screws 4 and nuts 5, an intercom 6, secured with a clamp 7 and a valve box 8, with a socket for a plug connection with a lung demand valve.

The valve box is attached to the body using a clamp 9 with a screw 10. The lung demand valve is fixed in the valve box by a spring 11. The lung demand valve is disconnected from the valve box by pressing the button 12. The exhalation valve 13 with a stiffness disk 14, an overpressure spring is installed in the valve box. 15. The valve box is closed by a cover 16, fixed to the valve box with screws 17.

On the head, the front part is attached using a headband 18, consisting of interconnected straps: frontal 19, two temporal 20 and two occipital 21, connected to the body by buckles 22 and 23.

The mask 24 with inhalation valves 25 is attached to the body of the front part using the intercom body and the bracket 26, and to the valve box - by nut 27 with washer 28.

The headband serves to fix the face on the user's head. Buckles 22, 23 allow a quick fit of the face part directly on the head.

For wearing the facepiece around the user's neck pending application, a neck strap 29 is attached to the lower buckles of the facepiece.

When inhaling, air from the submembrane cavity of the lung governed demand valve enters the submask cavity and through the inhalation valves into the submask. In this case, the panoramic glass of the front part is blown, which eliminates its fogging.

On exhalation, the inhalation valves close, preventing exhaled air from entering the face glass. The exhaled air from the undermask space is released into the atmosphere through the exhalation valve.

The spring presses the exhalation valve against the seat with a force that allows maintaining a predetermined excess pressure in the mask space of the face part.

The intercom provides the transmission of the user's speech when the face is worn on the face and consists of a body 29, a pressure ring 30, a membrane 31 and a nut 32.

The front part "Panorama Nova Standard" No. R54450 is dimensionless, universal. The front part of the Obzor PTS is selected depending on the anthropometric size of the person's head.

The selection of the front part of the Obzor PTS of the required body height should be made depending on the value of the horizontal (nodal) head circumference indicated in table. 3.2.

Table 3.2. Values ​​of the horizontal (cap) head circumference

The selection of the face part of the Obzor PTS according to the size of the mask should be made depending on the value of the morphological height of the face (the distance from the lower part of the chin to the point of transfer), indicated in table. 3.3.

Table 3.3. The values ​​of the morphological height of the face

Respiratory devices, depending on the climatic version, should be subdivided into:

Breathing apparatus for general purpose - apparatus designed for use at ambient temperatures from minus 40 ° C to 60 ° C, relative humidity up to 95% (at a temperature of 35 ° C);

Special-purpose breathing apparatus are apparatus designed for use at ambient temperatures from minus 50 ° C to 60 ° C, relative humidity up to 95% (at a temperature of 35 ° C).

Appointment requirements

4.1.1. A general-purpose breathing apparatus must be operable in breathing modes characterized by the performance of loads from moderate work (pulmonary ventilation 30 cubic dm / min.) To very heavy work (pulmonary ventilation 100 cubic dm / min.), In the ambient temperature range from minus 40 ° С to 60 ° С and humidity up to 95% (at a temperature of 35 ° С).

4.1.2. A special-purpose breathing apparatus must be operable in breathing modes characterized by the performance of the loads specified in 4.1.1, in the ambient temperature range from minus 50 ° C to 60 ° C and humidity up to 95% (at a temperature of 35 ° C).

4.1.3. The apparatus should include:

Suspended system;

Cylinder (s) with valve (s);

Reducer with safety valve;

Pulmonary demand valve;

Air hose;

Additional air supply device (bypass);

Sound signaling device;

Manometer (device) for monitoring the air pressure in the cylinder;

Front part with an intercom;

Exhalation valve;

Rescue device;

Quick disconnect connection for connecting a rescue device;

Bag (case) for the main face.

Note - The apparatus may include a quick fill for connecting a device for quick refueling of air cylinders.

4.1.4. The rated time of the protective action of the apparatus must be at least 60 minutes.

4.1.5. The actual time of protective action of the device, depending on the ambient temperature and the severity of the work performed, must correspond to the values ​​indicated in Table 1.

Design requirements

4.5.1. The device in the working position should be located on the back of a person.

4.5.2. The shape and overall dimensions of the apparatus must correspond to the structure of a person, be combined with protective clothing, helmet and firefighter equipment, ensure convenience when performing all types of work in the event of a fire (including when moving through narrow hatches and manholes with a diameter of (800 +/- 50) mm, crawling, on all fours, etc.).

4.5.3. The device must be designed in such a way that there is a possibility of putting it on after turning it on, as well as removing and moving the device without turning it off when a person moves through confined spaces.

4.5.4. The mass of the equipped apparatus without auxiliary devices used occasionally (rescue device, device for quick refueling of air cylinders, etc.), equipped with 1 cylinder, should not exceed 16.0 kg.

4.5.5. The mass of the equipped apparatus, equipped with 2 cylinders, should not be more than 18.0 kg.

4.5.6. All controls of the device (valves, levers, buttons, etc.) must be easily accessible, convenient for activating them and reliably protected from mechanical damage and accidental operation.

4.5.7. The controls of the apparatus must be actuated with a force not exceeding 80 N.

4.5.8. An air supply system should be used in the apparatus, in which, during breathing, in the undermask space of the face part, excessive air pressure should be constantly maintained in breathing modes characterized by the performance of loads from moderate work (pulmonary ventilation 30 cubic dm / min.) To very heavy work (pulmonary ventilation 100 cubic dm / min.) in the ambient temperature ranges from minus 40 ° C to 60 ° C (for a general-purpose apparatus) and from minus 50 ° C to 60 ° C (for a special-purpose apparatus).

4.5.9. The excess pressure in the mask space of the front part of the apparatus at zero air flow should be no more than 400 Pa.

4.5.10. The actual resistance to breathing on exhalation in the apparatus during the entire time of protective action should not exceed the values ​​indicated in Table 2.

Requirements for cylinders

4.6.1. The cylinders included in the apparatus must comply with GOST R "Fire fighting equipment. Small-displacement cylinders for breathing apparatus and self-rescuers with compressed air. General technical requirements. Test methods."

Compressed Oxygen Breathing Apparatus (DASK)

General device and principle of operation of DASK

A breathing apparatus with compressed oxygen (DASK) is a regenerative apparatus in which a gas breathing mixture is created by regenerating an exhaled gas mixture by absorbing carbon dioxide from it by a chemical substance and adding oxygen from a small-capacity cylinder available in the apparatus, after which the regenerated gas breathing mixture is fed to inhale.

DASK should be efficient in breathing modes characterized by the performance of loads: from relative rest (pulmonary ventilation 12.5 dm 3 / min) to very hard work (pulmonary ventilation 85-100 dm 3 / min) at an ambient temperature of -40 to + 60 ° С, and also remain efficient after staying in an environment with a temperature of 200 ± 20 ° С for 60 ± 5 s.

Rice. 2.1.

The nominal time of protective action (hereinafter referred to as the PDM) is the period during which the protective ability of the apparatus is maintained when tested on a simulator of human external respiration in the mode of performing medium-heavy work (pulmonary ventilation 30 dm 3 / min) and ambient temperature (25 ± 2) ° C. In the mode of performing work of medium severity (pulmonary ventilation 30 dm 3 / min) at an ambient temperature of (25 ± 1) ° C, the DASK for firefighters should be at least 4 hours.

The actual time of protective action is the period during which the protective ability of the device is maintained when tested on a simulator of human external respiration in the mode: from moderate work to very hard work (pulmonary ventilation 85 dm 3 / min) at an ambient temperature of -40 ° С to +60 ° С.

Modern DASK (Fig. 2.2) consists of airway and oxygen supply systems. Air duct system includes front part 7, moisture trap 2, breathing hoses 3 and 4, breathing valves 5 and 6, regenerative cartridge 7, refrigerator 8, breathing bag 9 and redundant valve 10. The oxygen supply system includes a control device (pressure gauge) 77, showing the supply of oxygen in the apparatus, devices for additional (bypass) 12 and main oxygen supply 13, locking device 14 and oxygen storage tank 15.

with compressed oxygen

The face part, which is used as a mask, serves to connect the airway system of the apparatus to the human respiratory system. The airway system, together with the lungs, constitutes a single closed system isolated from the environment. In this closed system, when breathing, a certain volume of air makes a variable movement in the direction between the lungs and the respiratory bag. Thanks to the valves, this movement occurs in a closed circulation loop: the exhaled air passes into the breathing bag along the exhalation branch (front part 7, exhalation hose 3, exhalation valve 5, regenerative cartridge 7), and the inhaled air returns to the lungs along the inhalation branch (refrigerator 8, inhalation valve 6, inhalation hose 4, front part 7). This pattern of air movement is called circular.

The exhaled air is regenerated in the airway system, i.e. restoration of the gas composition, which had the inhaled air before entering the lungs. The regeneration process consists of two phases: cleaning the exhaled air from excess carbon dioxide and adding oxygen to it.

The first phase of air regeneration takes place in a regenerative cartridge. As a result of the chemisorption reaction, the exhaled air is cleaned in the regenerative cartridge from excess carbon dioxide by the sorbent. DASK uses two types of chemisorbents of carbon dioxide from exhaled air: lime based on calcium hydroxide Ca (OH) 2 and alkaline based on sodium hydroxide NoOH. In our country, the KhP-I chemical absorbent is used. The reaction of absorption of carbon dioxide is exothermic, therefore, heated air enters the breathing bag from the cartridge. Depending on the type of sorbent, the air passing through the regenerative cartridge is either dehumidified or humidified. In the latter case, during its further movement, condensate falls out in the elements of the air duct system.

The second phase of air regeneration occurs in the breathing bag, where oxygen is supplied from the oxygen supply system in a volume slightly larger than that of a person consumes it, and is determined by the method of oxygen supply of a DASK of this type.

Regenerated air is also conditioned in the DASK air duct system, which consists in bringing its temperature and humidity parameters to a level suitable for human inhalation. Typically, air conditioning is about cooling it.

The breathing bag performs a number of functions and is an elastic container for receiving air exhaled from the lungs, which then enters for inhalation. It is made of rubber or gas-tight rubberized fabric. In order to provide deep breathing during heavy physical exertion and separate deep exhalations, the bag has a usable capacity of at least 4.5 liters. In the breathing bag, oxygen is added to the air leaving the regenerative cartridge. The breathing bag is also a condensate collector (if any); the dust of the sorbent is retained in it, which in small quantities can penetrate from the regenerative cartridge; the primary cooling of the hot air coming from the cartridge occurs due to heat transfer through the walls of the bag to the environment. The breathing bag controls the operation of the pressure relief valve and the lung demand valve. This control can be direct or indirect. In direct control, the wall of the breathing bag directly or through a mechanical transmission acts on the excess valve or the valve of the lung governed demand valve. In indirect control, these valves open when their own sensing elements (eg diaphragms) are exposed to the pressure or vacuum generated by the inhalation bag when it is filled or emptied.

The excess valve serves to remove excess gas-air mixture from the airway system and acts at the end of the exhalation. If the operation of the redundant valve is controlled indirectly, there is a risk of losing part of the gas-air mixture from the breathing apparatus through the valve as a result of accidental pressing on the wall of the breathing bag. To prevent this, the bag is placed in a rigid case.

The refrigerator serves to lower the temperature of the inhaled air. Known air coolers, the action of which is based on the transfer of heat through their walls into the environment. Refrigerators with a refrigerant are more efficient, the action of which is based on the use of the latent heat of phase transformation. Water ice, sodium phosphate and other substances are used as a melting refrigerant, ammonia, freon, etc. are used as evaporating into the atmosphere. Carbon dioxide (dry) ice is also used, which immediately transforms from a solid state into a gaseous state. There are refrigerators that are charged with refrigerant only when operating at elevated ambient temperatures.

The schematic diagram shown in Fig. 2.2, is generalized for all groups and varieties of modern DASK.

In various DASK models, three schemes of air circulation in the air duct system are used: circular (see Fig. 2.2), pendulum and semi-pendulum.

The main advantage circular pattern - the minimum volume of harmful space, which includes, in addition to the volume of the front part, only a small volume of air ducts at the junction of the branches of inhalation and exhalation.

Pendulum scheme differs from the circular one in that the branches of inhalation and exhalation are combined in it, and air moves along the same channel alternately (like a pendulum) from the lungs to the breathing bag, and then in the opposite direction. With regard to the circular scheme (see Fig. 2.2), this means that there are no breathing valves 5 and 6 in it, the hose 4 and refrigerator 8 (in some devices, the refrigerator is placed between the regenerative cartridge and the front part). The pendulum circulation scheme is used mainly in apparatuses with a short time of protective action (in self-rescuers) in order to simplify the design of the apparatus. The second reason for using such a scheme is to improve the sorption of carbon dioxide in the regenerative cartridge and to use for this additional absorption of it during the second passage of air through the cartridge.

The pendulum air circulation pattern is characterized by an increased volume of harmful space, which, in addition to the front part, includes a breathing hose, the upper air cavity of the regenerative cartridge (above the sorbent), as well as the air space between the spent sorbent grains in its upper (frontal) layer. With an increase in the height of the spent sorbent layer, the volume of the specified part of the harmful space increases. Therefore, DASK with pendulum circulation is characterized by an increased content of carbon dioxide in the inhaled air compared to the circular pattern. In order to reduce the volume of the harmful space to a minimum, the length of the breathing hose is reduced, which is possible only for devices located in a working position on a person's chest.

Semi-pendulum scheme differs from the circular one in the absence of an exhalation valve 5 (see Fig. 2.2). When you exhale, air moves through the exhalation hose 3 and a regenerative cartridge 7 into a breathing bag 9 in the same way as in a circular pattern. When inhaling, the bulk of the air enters the face 1 through the refrigerator 8, inhalation valve 6 and inhalation hose 4, and some of its volume passes through the regenerative cartridge 7 and the hose 3 in the opposite direction. Since the resistance of the exhalation branch containing a regenerative cartridge with a sorbent is greater than the inhalation branch, a smaller volume of air passes through it in the opposite direction than along the inhalation branch.

There are known DASKs with a circular air circulation pattern, in which, in addition to the main respiratory bag 9 (see Fig. 2.2), there is an additional bag located between the exhalation valve 5 and the regenerative cartridge 7. This bag serves to reduce the resistance to exhalation due to "smoothing" peak value of the volumetric air flow.

At the beginning of the last century, devices with forced air circulation through a regenerative cartridge were widespread. They had two breathing bags and an injector fed with compressed oxygen from a cylinder and sucking air through a regenerative cartridge from the first bag to the second. This technical solution was due to the fact that at that time the regenerative cartridges had high resistance to air flow. Forced circulation, on the other hand, made it possible to significantly reduce the resistance to exhalation. In the future, injection devices did not become widespread due to the complexity of the design, the creation of a rarefaction zone in the air duct system, which contributes to the suction of outside air into the device. The decisive argument in the rejection of the use of injection devices was the creation of more advanced regenerative cartridges with low resistance. During the period of application of injection devices and after the abandonment of them, all other devices were called the outdated term "pulmonary-power breathing apparatus".

The refrigerator is an obligatory element of DASK. Many outdated models do not have it, and the air heated in the regenerative cartridge is cooled in the breathing bag and the inhalation hose. Known air (or other) refrigerators located after the regenerative cartridge, in a breathing bag, or constituting a single constructive whole with it. The last modification also includes the so-called "iron bag" or "inside out bag", which is a sealed metal reservoir, which is the DASK body, inside which there is an elastic (rubber) bag with a neck, communicating with the atmosphere. The elastic container, which receives air from the regenerative cartridge, in this case is the space between the walls of the tank and the inner bag. This technical solution is characterized by a large surface area of ​​the tank serving as an air cooler and significant cooling efficiency. Also known is a combined breathing bag, one of the walls of which is at the same time the lid of the apparatus knapsack and the air cooler. Breathing bags combined with air coolers, due to the complexity of the design, which is not compensated for by a sufficient cooling effect, are currently not widespread.

A redundant valve can be installed anywhere in the airway system except in the area where oxygen is directly supplied. However, valve opening (direct or indirect) must be controlled by a breathing bag. If the supply of oxygen to the airway system significantly exceeds its consumption by a person, a large volume of gas is released into the atmosphere through the excess valve. Therefore, it is advisable to install the specified valve before the regenerative cartridge in order to reduce the load on the cartridge for carbon dioxide. The place of installation of the redundant and breathing valves in a specific model of the device is selected for design reasons. There are DASKs in which, in contrast to the diagram shown in Fig. 2.2, breathing valves are installed on the top of the hoses at the junction box. In this case, the mass of the apparatus elements per person increases slightly.

Variants and modifications of the basic diagram of the oxygen supply system of breathing apparatus with compressed oxygen are predetermined, first of all, by the method of oxygen reservation, implemented in this apparatus.