Gas masks GP-7

Modern gas masks, including the GP-7 series, provide the most effective protection against exposure to hazardous substances and have a convenient design. Today these devices are widely used in various fields. Due to the operational properties of civilian gas masks, the risk of many negative and dangerous influences is minimized. With timely replacement of filter elements, GP-7 can be used up to 12 hours.

Initially, it is worth paying attention to the history of the appearance of means for protection against various toxic substances. More than a century ago, back in 1915, German troops began to actively use chlorine and other agents in the course of hostilities. Based on this, an immediate development of a device was required that protects against chlorine, ammonia and other poisons. It was then that Academician Zelinsky created a coal-based filter element for protective equipment.

Now one of the most common modifications is the GP-7. We are talking about civilian equipment, the main purpose of which is timely and most effective protection against negative effects:

• radiation;
• hazardous chemicals;
• bioaerosols.

A civilian gas mask of this type, like all similar devices, belongs to the category of filtering ones. It is important to take into account that the basic configuration does not provide for protection against ammonia, which requires a DPG-3 cartridge. The latter should be connected to the FPK, which is part of the standard kit. It should be noted that the ROM-PC cartridges can be used autonomously.

Having studied the instructions of the manufacturers, as well as the detailed descriptions of the analyzed devices and devices available on the World Wide Web, we can conclude that the basic configuration consists of:

• masks;
• FPK;
• 6 anti-fog glasses films;
• 2 clamping elements in the form of rings or rubber cords;
• 2 sealing elements;
• bags;
• instructions.

It should be noted that the described model has become an intermediate link in the line between the GP-5 and GP-9 devices. Compared to its predecessor, it has the following advantages:

• minimum resistance of the filter box, which makes breathing easier;
• maximum valve reliability;
• maximally increased tightness and significantly reduced exposure of the mask during the operation of the apparatus;
• high level of voice transmission quality.

First of all, it is worth paying attention to the design features, structure, composition of the filtering-absorbing unit and, of course, its purpose. This component of the GP is responsible for the effective (almost complete) purification of the air inhaled by a person from the majority of potentially dangerous impurities. This box is made of ordinary tin or aluminum. Special stiffening ribs give increased strength and resistance to damage to the cylindrical body.

If the device is in storage, then this structural element is tightly closed with a special cap with a gasket to ensure maximum tightness. On the opposite side, that is, in the bottom of the FPC, there is an opening through which air enters the filter. It should also be tightly closed with a special stopper during storage.

One of the important structural elements is the spectacle assembly with observation glasses. During operation, special anti-fog films are installed on the latter. It is also provided for the installation of insulation cuffs at low temperatures. This allows you to maintain full transparency of the glass in almost any operating conditions. In addition, the design of the described unit includes such components as:

• an obturator in the form of a thin strip made of soft rubber and ensuring maximum tightness;
• a device with a membrane, which is responsible for the transmission of speech;
• locking mechanisms of breathing blocks;
• a system of straps that allow you to adjust the mask and fix it with maximum tightness.

The last structural element includes a plate (occipital) and 5 straps - one frontal, as well as two temporal and buccal. In the situation with the latter, we are talking about metal fixing devices, and the rest of the straps are fixed with plastic buckles. In this case, all belts have step-type stops.

The principle of functioning of the described apparatus is identical in everything to the algorithm of action of most of its "brothers". At the same time, the civilian gas mask of the 7th series is characterized by such obvious advantages as:

• minimized FPK resistance;
• the most reliable valve actuation and minimization of the risks of their damage, provided by the unique shape of the petals;
• the possibility of long-term and maximally comfortable (minimal maxi pressure on the face is created) operation of the device even in the most difficult conditions;
• maximum tightness, which remains even if the straps are damaged.

A high-quality membrane guarantees clear transmission of sounds, which allows the use of communication means.

When determining the scope of application of civilian personal protective equipment, including the modification in question, special attention should be paid to their main performance indicators, the list of which includes:

• the weight of the basic configuration excluding the bag (kg) - 0.9;
• FPK weight (kg) - 0.25;
• mask weight (kg) - 0.6;
• visibility - from 60%;
• dimensions of a gas mask folded and placed in a bag (m) - 0.285 / 0.21 / 0.115;
• fluctuations in temperatures at which it is possible to use the device - from -40 to +40 degrees;
• air resistance at the stage of inhalation (mm of water column) - within 18;
• the presence of carbon dioxide - should not exceed 1%;
• the resistance of the mask on inhalation / exhalation (mm of water column) - no more than 2/8, respectively;
• the rate of penetration of CMT into the filter module and directly under the mask itself is no more than 0.001%.

In addition, the duration of the active phase of protection provided by a serviceable filter element is of decisive importance. With a flow rate of air inhaled by a person during the operation of a gas mask within 30 dm3 / min for various potentially hazardous substances is at least (min):

• chlorine (5 ml / dm. cube) - 40;
• chlorocyanogen (5 ml / dm. cube) - 18;
• nitrobenzene (5 ml / dm 3) - 40;
• hydrochloric and hydrocyanic acid (5 ml / dm. cube) - 20 and 18;
• phenol (0.2 mg / dm. cube) - 200;
• tetraethyl lead (2mg / dm. cube) - 50;
• ethanethiol (5mg / dm. cube) - 40;
• hydrogen sulfide (10mg / dm. cube) - 25.

Today the GP-7 is already considered an outdated model of civilian gas masks. The newer versions are more reliable, efficient, easier to use and more functional.

This protection has the following advantages:

• the presence of a coal-based catalyst;
• maximum resistance of FPC to corrosion and aggressive environment;
• tightness provided by the plasticity of materials;
• compact size and minimum weight;
• wide scope of application;
• the possibility of using in case of contamination of the environment with ammonia.

The GP-7BTV modification is distinguished by the maximum quality of transmitted sounds. Among other things, it is worth paying attention to such operational properties as increased strength and durability.

The choice and fitting of the mask is one of the key components of the operation of the described devices. Initially, you need to define both key head sizes. To find the horizontal size, you should draw a conditional line along the eyebrows and the most protruding part of the back of the head, 2-3 centimeters above the ears. To determine the vertical size, a line is drawn through the chin and crown.

Based on the measurement results, a suitable size is determined. In this case, we are talking about the growth of the gas mask, as well as the position of the stops of the headband straps. Now, on the vastness of the World Wide Web, you can easily find tables that greatly facilitate the sizing procedure.

If the sum of the two mentioned sizes reaches 1 210 mm, then the straps are set at 3-7-8.

For growth No. 2, with the total girths within 1215-1235 mm, the stops are set at 3-7-1, and if the total value of these dimensions reaches 1260 mm, then the straps should be fixed according to the 3-6-7 scheme.

With the third size, the following options are possible:

• in the range from 1,265 to 1,285 mm - 3-7-7;
• up to 1 310 mm - 3-5-6;
• more than 1315 mm - 3, 4, 5.

It is worth focusing on the numbering of the belts. In this situation, the first, second and third numbers are the frontal, temporal and buccal straps, respectively.

After you receive a gas mask of the appropriate size, you need to pay attention to its completeness. The algorithm of actions includes the following steps.

1. Remove the device from the package.
2. Pull out the insert by placing it back in the box.
3. Thoroughly inspect all parts of the structure to identify defects and incompleteness. In particular, we are talking about the presence of all buckles.
4. Remove the screen and unscrew the outer saddle of the exhalation valve to check the condition of its petals. In parallel, the presence and integrity of the sealing element is checked.
5. Examine carefully glasses of glasses and clamping elements for films (rings or cords) in order to identify cracks, chips and other damage. The clamping elements must be inserted into the corresponding grooves of the goggle assembly.
6. Make sure that the inhalation assembly and the fairing fasteners are in good working order. A ring-shaped gasket must be present in the valve seat.

The next step will be the assembly of a civilian gas mask of the GP-7 series, carried out according to the manufacturer's instructions. The procedure is presented below.

1. Thoroughly wipe the front of the device inside and out with a damp, clean cloth or cotton wool.
2. Dry the treated mask completely.
3. Remove the rubber shield and unscrew the outer saddle to purge the expiratory block shut-off device.
4. Unscrew the cap, equipped with a gasket, from the filter box, and from its bottom - the plug. After dismantling, all the listed elements must be placed in a plastic wrap from under the front part and put into one of the compartments of the bag.
5. Putting the mask in one hand, connect the filter element with the other, screwing it in until it stops.
6. Remove the clamping elements (rings or cords made of rubber) from the seating grooves of the glasses block.
7. Wipe down the glass.
8. Open the NPN and remove the 2 anti-fog elements. The rest of the films together with the box must be tightly closed and placed in one of the compartments of the bag.
9. Gently taking the film, place it in the grooves of the glasses.In this case, it does not matter which side of the film will be turned to the glass.
10. Replace the hold-down cord or ring. In this case, it is important to carefully tuck them into the corresponding grooves.
11. With the second anti-fog film, you must do the same.

It is important to remember to be able to properly wear a gas mask.

The procedure for putting on the device provides for a number of simple steps, namely:

• place a gas mask in your hands, placing your thumbs inside;
• place the chin in the recess of the obturator formed in its lower part;
• put on the headgear by moving up and at the same time back;
• tighten and fix the cheek straps as much as possible;
• if even small distortions of the mask, obturator or belts are detected, they must be eliminated.

If there are distortions in the chin area, you will need to remove the gas mask and adjust the length of the corresponding straps.

It must be remembered that a GPU, like any other device, has a definite full service life. The creators of the devices under consideration have developed special rules for operation, as well as storage. And we are talking, in particular, about the following important points.

1. It is required to prevent damage to structural elements as much as possible. This applies not only to the filter module, but also to the shut-off devices of the inspiratory and expiratory blocks.
2. Particular attention should be paid to the intercom, the membrane of which should not get dirt, sand and dust.
3. It is necessary to prevent even the slightest ingress of moisture into the filter element. In other words, the gas mask should be kept as dry as possible.
4. All such devices designed to protect against harmful substances must be stored away from heat sources at least 3 meters.

It is worth considering that the shelf life of the described type of civil protective equipment guaranteed by the manufacturer is 12 years. At the same time, the maximum indicator in this case can reach 25 years from the date of release of the device. After this period, GP-7 is subject to mandatory replacement.

For an overview of the GP-7 gas mask, see below.