Film lover's sports equipment and rules of swimming underwater. Domestic scuba gear Scuba gear scheme

When using equipment with an open breathing pattern, air is supplied using a breathing
machine, for the swimmer to inhale, and the exhaled air, through the exhalation valve, is removed into the environment (water).

Equipment with an open breathing pattern can be autonomous or non-autonomous. In self-contained equipment, air for inhalation is supplied from cylinders attached to the swimmer’s back. In a non-autonomous system, air is supplied through a hose from the surface.

A combined version of equipment is also possible. In a normal situation, air from the surface is supplied through a hose through a remote unit or receiver (which is used as one of the apparatus’s cylinders) for the swimmer to inhale. When emergency situation or the air supply from the surface stops, the diver switches to breathing from scuba gear.

Equipment with an open breathing pattern

Currently, in devices with an open breathing circuit (with exhalation into water), two schemes for reducing (pressure reduction) high-pressure air are used:

1. single-stage reduction.
2. two-stage reduction.

In the first case, the high pressure of the air in the cylinders (working pressure) is reduced to a pressure environment in one stage, in a pulmonary demand valve.

In the second case, the high air pressure is reduced to ambient pressure in two stages. In the reducer there is a reduction to the intermediate (set) pressure. Next in the pulmonary demand valve set pressure decreases to ambient pressure.

The main parts of any scuba gear are cylinders, a lung demand valve with a reducer, inhalation and exhalation tubes, a set of clamps and suspension belts.

Device AVM-1 (Podvodnik-1)

The design of the scuba gear (gearbox) uses the ideas inherent in the design of gearboxes of the “MISTRAL” series (France).

The device has the following technical data:

Each cylinder of the AVM-1 apparatus has its own shut-off valve (a KVM-200 valve is installed). A high pressure pipeline is attached to the shut-off valves. When the shut-off valves are opened, air from the cylinders flows through high-pressure pipelines into the reducer. The pipelines to the cylinders and to the reducer are secured using union nuts with seals.

The main part of the device is a gearbox with a lung demand valve. The design of the gearbox and lung demand demand valve is described in the article on the AVM-1m device.

To control the air supply in the cylinders, a remote minimum pressure indicator with a pressure gauge is used. The design of the pointer is described in the article on the AVM-1M device.

The difference between the AVM-1 and AVM-1m devices is in the location of the valves. AVM-1 has a valve on each cylinder. AVM-1M has one valve.

Device AVM-1M

The device is designed for autonomous descents under water to depths of up to 40 meters.

Specifications.

• Working pressure – 150 ati.
• The set pressure of the reducer is 5-7 ati.
• The response pressure of the safety valve is 9-11 ati.
• The reserve air pressure is 30 ati.
• The capacity of the cylinders is 2 x 7 liters.
• The air supply in cylinders is 2 x 7 liters per 150 ati = 2100 liters.
• The mass of the device in air with empty cylinders is 20.8 kg.
• The mass of the device in air with full (filled to an operating pressure of 150 ati) cylinders is 23.5 kg.
• Buoyancy in fresh water:
• with empty cylinders positive - 0.6 kg.
• With full cylinders negative - 2 kg.

Description of the device

The AVM-1m device consists of the following main parts (Fig. 1)

(1), (4) corrugated inhalation and exhalation tubes.

(2) mouthpiece.

(3) mouthpiece box.

(5) headband.

(6) air supply valve.

(7) shoulder straps.

(8) cylinder mounting clamp.

(9) strap for connecting shoulder straps.

(10) foam insert.

(11) buckles for fastening belts.

(12) waist belt.

(13) waist belt buckle.

(14) carabiner for attaching the shoulder strap.

(15) shoulder strap.

(16) cylinders.

(17) high pressure gauge hose.

(18) high pressure gauge and minimum pressure indicator.

(19) charging connection.

(20) gearbox and lung demand valve.

The AVM-1m device has two 7-liter cylinders, the cylinders are fastened with clamps, and an angle fitting with high-pressure tubes and union nuts is screwed into the neck of each cylinder on a lead lash. The shut-off valve is installed on the high-pressure pipeline connecting the apparatus cylinders and is attached to it with union nuts. A reducer and a lung demand valve are attached to the shut-off valve on a special platform. A high-pressure hose is connected to the shut-off valve fitting, leading to the charging fitting and then to the minimum pressure indicator with a pressure gauge.

To increase the buoyancy of the device, a foam insert is installed between the cylinders. In later releases there is no foam insert.

To put the apparatus on the diver’s back, there are belts: shoulder, waist, and shoulder straps.

Picture 1

Cylinders

The device is equipped with cylindrical cylinders with a capacity of 7 liters. The cylinders are made of alloy steel and are designed for a working pressure of 150 kgf/cm2.

Each cylinder has a stamp indicating the following information:

• manufacturer's trademark.
• month and year of manufacture of the cylinder.
• year of the next hydraulic test (once every 5 years).
• working pressure in atm.
• test pressure in atm (1.25 from the working one).
• actual capacity of the cylinders in liters.
• nominal capacity of the cylinder in liters.
• weight of the cylinder without valve.
• cylinder number.
• OTK stamp.

Design and operation of a shut-off valve. (Fig. 2).

The operating principle and main parts of all shut-off valves of any devices are similar. The difference may be in the design of the housing, flywheel, material and dimensions of parts.

The valve consists of a body (8), a shut-off valve (3), a spindle (5), a plug (9), a block (4), a flywheel (6), the flywheel is held on the spindle by a nut with a spring.

The valve of the AVM-1M device has four fittings (1). A gearbox and a lung demand valve are attached to the top one using a bolt and two second-layer gaskets-rings (see Figure 2). A high-pressure brass tube is connected to the lower one, going to the charging fitting and the minimum pressure indicator with a pressure gauge. High-pressure tubes from the cylinders are attached to the right and left fittings (not shown in the figure) with union nuts.

When the flywheel (6) rotates counterclockwise, rotation is transmitted through the spindle (5) and the block (4) to the valve (3). The valve (3)t is unscrewed and opens the access of air from the cylinders to the pressure regulator and at the same time to the charging fitting and the minimum pressure indicator. When the flywheel rotates clockwise, the valve (3) sits on the seat and the access of air from the cylinders stops.

For installation of the gearbox and lung demand valve, a platform is provided on the valve body (visible in the figure). There are two holes in the platform into which threads are cut and adjusting screws are screwed in. The screws adjust the installation of the gearbox relative to the platform.

Operating principle and design of the pulmonary valve and gearbox (Fig. 3)

Gearbox parts:

(17) adapter.

(16) strainer.

(18) gear valve with fluoroplastic insert.

(15) double arm lever.

(14) gear diaphragm.

(13) pusher.

(12) pusher spring.

(11) adjusting nut.

(10) safety valve.

(9) safety valve adjusting nut and spring.

Pulmonary demand valve parts:

(1) fitting for connecting a corrugated exhalation hose.

(3) valve body cover.

4) exhalation petal valve.

(6) pulmonary valve membrane with a rigid center.

2) lower lever of the lung demand valve.

7) upper lever of the lung demand valve.

(8) fitting for connecting a corrugated inhalation hose.

(5) nut and washer for fastening the gearbox diaphragm.

(22) Upper arm adjustment screw.

(21) valve seat of the lung demand valve.

(20) lung demand valve valve with spring.

(19) adjusting nut.

When closed shut-off valve under the action of its spring, the pusher, moving to the left, presses on the two-arm lever, the lever rotates clockwise around its axis, while the gearbox valve is in a free state. After opening the shut-off valve (Fig. 4-a), air opens the valve and fills the cavity of the gearbox until the gearbox membrane, arching upward, turns the two-arm lever around its axis, counterclockwise (Fig. 4-b). The two-arm lever will turn when the pressure in the gearbox cavity is equal to the pusher spring adjustment pressure (set pressure 5-7 ati). In this case, the double-arm lever with its upper lever presses and closes the gearbox valve, and with its lower lever it moves the pusher to the right and compresses the spring. Thus, the air in the gearbox cavity is under set pressure.

When you inhale (Fig. 4-c), a vacuum is created in the internal cavity of the pulmonary demand valve, the membrane of the valve bends and presses on the upper lever. The upper lever presses on the lower one, and that in turn, with the platform of its adjusting screw, presses on the valve stem of the pulmonary valve. The valve compresses its spring and opens air access from the gearbox cavity to the lung demand valve cavity and further to the swimmer.

At the end of inhalation (Fig. 4-d), the deflection of the lung valve membrane decreases, the pressure on the levers weakens, and the valve of the machine closes under the action of its spring (sits on the saddle). At the same time, the pressure in the reducer cavity drops, the pusher with the spring comes into operation, the reducer valve opens, and air from the cylinders enters the reducer cavity until the set pressure is reached.

If the gearbox malfunctions and the pressure in it rises above the set pressure, the safety valve comes into operation. The safety valve spring is compressed, the valve moves away from the seat, and excess air is released into the water. The activation of the safety valve serves as a signal that the gearbox is malfunctioning; the diver must immediately begin ascent to the surface.

In order to inhale, the diver must create a certain vacuum above the lung valve membrane (approximately 50 mm of water column). The magnitude of the vacuum (breathing resistance) is also affected by the location of the lung demand valve. When determining the amount of resistance during inhalation, the difference between the lung demand demand valve and the center of the diver's lungs should be taken into account. This value will change depending on the diver's position. At vertical position diver, when the center of the lungs and the pulmonary demand valve are almost at the same level, the resistance arising due to the difference in hydrostatic pressure is insignificant. In a horizontal position (when swimming), the lung demand valve is located above the center of the lungs; when inhaling, the diver overcomes the mechanical resistance of the apparatus and the resistance equal to the difference in hydrostatic pressure at the levels of the center of the lungs and the location of the breathing machine. When the diver works in a supine position, inhalation is performed with slight resistance. And when you exhale, the resistance will increase, since the pulmonary demand valve is located below the center of the lungs.

This problem does not exist in devices with spaced reduction stages (Ukraine-2, AVM-5).

Often during operation of the AVM-1m, due to negligence or inattention, the lung demand valve becomes deformed and fails. In this case, it is necessary to remove the remains of the lung demand valve, as shown in Figure 5. Make an adapter and screw it into the gearbox. The place for the adapter is marked with the letter “A”. Connect a pulmonary valve from the AVM-5 or from the Ukraine-2 device to the adapter. The thread at the point of connection to the gearbox must have at least 5 full turns. The external thread is selected depending on the existing pulmonary valve hose.

Between the manufactured fitting and the lung demand valve hose, you can install a tee for the compensator or octopus hose.

Charging connection (Figure 8).

When charging the device with compressed air, a charging tube from the compressor (filter) is attached to the charging fitting. The charging fitting is located and fixed on the upper clamp of the left cylinder (see Fig. 1, item 19), the fitting is connected by a brass tube to the shut-off valve. A high-pressure hose leading to the minimum pressure indicator is connected to the charging fitting at the bottom.

A seat (4) is inserted into the fitting body, into which a return valve (3) with a spring (2) is inserted. A plug (7) with a gasket (8) is screwed onto the charging connection from the outside. There are modifications of the device in which the charging connection is not equipped with a return valve.

To charge the device you need:

1. With the shut-off valve closed, unscrew the plug (7). First you need to make sure that the pressure gauge of the minimum pressure indicator shows “0”
2. Screw the air supply tube from the compressor to the charging connection
3. Open shut-off valve

Air from the compressor or transport cylinder will enter the charging fitting, then pass through the filter (5) of the charging fitting, press the return valve and begin flowing into the cylinders of the device through the open shut-off valve.

After the air supply from the compressor stops, the return valve will close under the action of its spring (2).

Minimum pressure indicator with pressure gauge (Fig. 7).

The minimum pressure indicator and the pressure gauge connected to it are used to monitor the consumption of air from the apparatus cylinders. In clear water, you can use a pressure gauge, in muddy water or at night - with a minimum pressure indicator.

The pointer (pointer body) is attached to the left (Fig. 1) shoulder strap. To attach the pointer, a special holder is used, which allows the diver to rotate the pointer for ease of taking readings.

The indicator body has channels leading to the pressure gauge and to the indicator diaphragm.

The minimum pressure indicator is cocked before opening the shut-off valve. In order to cock the pointer, you need to press and hold the head of the pointer rod (5) Fig. 7 with your finger, then open the shut-off valve. After opening the valve, high-pressure air flows through a brass tube to the charging fitting, and then through a high-pressure rubber hose to the minimum pressure indicator and pressure gauge. Under air pressure, the diaphragm (10) of the indicator bends and, overcoming the force of the spring, moves the locking rod (8), which enters beyond the protrusion of the cocked indicator rod (5). After this, you can stop holding the head of the indicator rod; the indicator will remain in the cocked position. When the pressure in the cylinders approaches the reserve (30 ati), the spring of the locking rod will begin to move and the pointer will disengage with a slight click under the action of its spring (6). The click can be heard in the water. By periodically feeling the pointer, you can determine in what position the pointer rod is. And, therefore, determine when the reserve air supply will occur. Next, the pressure needs to be monitored using a pressure gauge.

Adjustments of the AVM-1m device

— ;

— Adjustment of the safety valve response;

— Adjustment of the response of the minimum pressure indicator;

— Adjustment of lung demand valve levers (inhalation resistance);

— Adjustment of the pulmonary valve valve.

Adjusting the set pressure of the reducer.

Before adjustment, it is necessary to measure the setting pressure of the reducer.

To measure you need:

— install the gearbox on the device;

— close the shut-off valve;

— instead of the lung demand valve plug (19a) Fig. 3, install a control pressure gauge;

(the diagram for attaching the control pressure gauge to the gearbox is shown in Figure 9, the appearance of the control pressure gauge is shown in Figure 11).

Proceed with adjustment, if necessary (reducer set pressure 5-7 atm):

— Unscrew the safety valve body.

— special key or use a screwdriver to unscrew or tighten the adjusting nut (11) Fig. 3, the adjusting nut compresses or releases the pusher spring (12), if it compresses, the installation pressure increases, if it expands, it decreases.

— install the safety valve in place.

— measure the installation pressure.

- if the resulting value differs from the required one, start adjusting again.

Adjusting the safety valve response

The operating instructions for the AVM-1m device require the use of a repair and control unit (RKU-2) when adjusting the safety valve. The repair and control installation is shown in Figure 10. The safety valve is unscrewed from the gearbox, screwed to the RKU-2 fitting, and then adjustment is made (using the adjusting nut (9) Figure 3, the degree of compression of the valve spring changes). In practice, in field conditions, the RKU is not always at hand.

• install the control pressure gauge as in adjusting the set pressure.
• remove the lung demand valve cover (3) Fig.3.
• pull out the lung demand valve membrane (6).
• fold down the levers (2) and (7).
• open the shut-off valve.
• Use the handle of a screwdriver or a wrench to press the nut (5), when the safety valve starts to operate, read the readings on the control pressure gauge.
• if the readings differ from the required ones (9-11 ati), proceed with adjustment (compress or release the valve spring).
• After adjustment, assemble the gearbox and lung demand valve.

If there is no control pressure gauge, and the set pressure of the gearbox is correctly adjusted, the adjustment can be made as follows:

— open the shut-off valve.

— slowly rotate the adjusting nut (9) counterclockwise (Fig. 3).

— when the safety valve starts to work, record this moment.

- make ½ turn clockwise.

- tighten the lock nut.

Adjusting the position of the lung demand valve levers (inhalation resistance).

The distance between the upper lever (7) Fig. 3 and the membrane (6) determines the amount of resistance during inhalation.

— remove the lung demand valve cover (3) Fig. 3.

— pull out the lung demand valve membrane (6).

— instead of a membrane, place a ruler on the body; the distance between the ruler and the upper lever should be approximately 3 mm.

— by rotating the adjusting screw of the lower lever (22), achieve desired position levers and membranes.

— assemble a pulmonary valve.

Adjustment of the lung demand valve valve (air flow).

The pulmonary valve valve (20) Fig. 3 on the surface should provide an air flow of 30 liters per minute.

The adjustment is made on RKU-2, using a rheometer-pressure gauge.

In practice you can do this:

— unscrew the plug of the lung demand valve (19a) Fig. 3.

— completely unscrew the adjusting screw (19).

- slowly screwing in the screw (19), set the moment when the lung valve valve spring begins to compress.

— make three full turns with the screw (19).

— screw the plug (19a).

Adjusting the response of the minimum pressure indicator

The minimum pressure indicator rod should operate when the residual pressure in the cylinders is 30 ati.

Before adjustment, the indicator response is measured:

— cock the pointer.

— open the shut-off valve (during this check, the cylinder must be charged at least 50 ati).

— make sure that the pointer is cocked.

— close the shut-off valve.

— slowly inhale, monitoring the readings of the pressure gauge on the pointer.

— at 30 ati the pointer should work.

If the pointer does not work at 30 ati, proceed with adjustment:

- relieve pressure.

— unscrew the indicator housing (1) Fig. 7.

— compress or release the rod spring (8) using the adjusting nut (3) Fig. 7.

— collect a pointer.

Device AVM-1M-2

• The device is a modification of the AVM-1M device.
• The design of the gearbox and lung demand demand valve is completely similar to the AVM-1M device
• The AVM-1M-2 device has three cylinders with a capacity of 7 liters.
• The mass of the apparatus in air with empty cylinders is 33 kg.
• Weight of the device in air with full cylinders – 36 kg

Changes have been made to the design of the shut-off valve of the AVM-1M-2 device.

A transfer switch with a physiological indicator is installed in the valve body.

Before entering the reducer, the air presses the control valve, when the pressure in the cylinders drops to the control valve spring adjustment pressure (30 ati), the spring will close the control valve and inhalation air will flow through the bypass channel. In this case, the diver will feel resistance when inhaling. Next, the diver must pull the remote reserve activation bulb, the control valve spring is compressed, and the valve opens under the residual air pressure. The swimmer can again breathe freely and begin to rise to the surface.

The AVM-1M-2 device does not have a minimum pressure indicator with a pressure gauge.

Device AVM-3

Appearance of the device.

1. Corrugated pulmonary valve inhalation hose
2. Mouthpiece box
3. Corrugated pulmonary valve exhalation hose
4. Air cylinder
5. Chest strap
6. Cylinder mounting clamp
7. Shoulder strap
8. Air cylinder
9. Belt
10. Bracelet belt
11. Charging connection
12. High pressure gauge
13. Protective cover
14. Backup air valve
15. Main air supply valve
16. Protective cover for lung demand valve
17. Pulmonary demand valve

The AVM-3 device has two cylinders (4) and (8) connected by upper and lower clamps (6). The cylinders are installed with their necks down and connected to each other by a high-pressure tube.

At the bottom of the device there is a main air supply valve (15) with a charging connection (11), a backup air supply valve (14), a high-pressure pressure gauge (12), and a gearbox (covered in the figure with a casing). To prevent mechanical damage The parts of the lower part of the device are protected by a removable protective cover (13).

In the upper part of the device there is a pulmonary valve (17) with corrugated inhalation (1) and exhalation tubes (3). The tubes are connected to a mouthpiece box (2), which has a fitting for attaching a mouthpiece or for attaching a diving suit to a helmet. The lung demand valve is connected to the reducer by a medium pressure tube. To prevent mechanical damage, the lung demand valve is protected by a removable protective casing (16).

A system of belts (5), (7), (9), (10) is designed to secure the apparatus on the swimmer’s back.

Technical characteristics of the device.

• Number and capacity of cylinders: 2 x 5 l
• Working pressure: 150 ati
• Gearbox set pressure: 3-4 ati
• Total air supply in cylinders: 1500 l
• Reserve air supply in cylinders: 300 l
• Weight of the device in air with empty cylinders: 19 kg
• With full cylinders: 21 kg
• Buoyancy of the device in fresh water with empty cylinders: -0.5 kgf
• With full cylinders: -2.5 kgf
• Charging connection thread: ¼” pipe

Scheme of operation of the device (stand-alone version)

The operation diagram is shown in Figure 8.

Air from cylinders (16) and (21) flows to the shut-off valve (25). The shut-off valve and charging connection are installed on the cylinder (21). The cylinder (21) and the cylinder (16) are connected by a high-pressure tube (24). After opening the shut-off valve (25), air flows through the high-pressure pipe (23) into the reserve air supply valve (22). Next, pressing the control valve of the reserve supply valve (the control valve is adjusted to the pressure of the reserve air supply of 20-30 ati), air enters the reducer through the tube (15). In the diagram, the gearbox parts are indicated by numbers: (17), (18), (19), (20), (28), (29). In the reducer, the air pressure is reduced to 3-4 ati (set pressure). Next, the air through the medium pressure tube (11) enters the lung demand valve (9). In the figure, the parts of the lung demand valve are indicated by numbers: (5), (6), (7), (8), (10), (26), (27). In the lung demand valve, the pressure of the incoming air is reduced to ambient pressure, then the air flows through the hose (4) for the swimmer to inhale. The exhaled air through the exhalation hose (3) enters the exhalation petal valve (5) and is removed into the environment (water). When the pressure in the cylinders decreases to reserve. The control valve of the reserve valve closes the main air supply channel and the diver feels resistance when inhaling. Next, the diver must open the reserve valve and begin to rise to the surface.

When using the AVM-3 device in a hose version, air is supplied through the hose directly to the lung demand valve. To connect the hose from the surface, the lung demand valve has a special fitting (12). In the event of an emergency and the air supply from the surface is cut off, the diver opens the main air supply valve and breathes from the apparatus cylinders.

Gearbox operation diagram.

The gearbox design is shown in Figure 3.

Scheme of operation of a pulmonary valve.

The device of the pulmonary demand valve is shown in Figure 4yu

The main air supply valve design is shown in Figure 5.

The design of the backup air supply valve is shown in Figure 6.

Adjustments of the AVM-3 device

Device AVM-4

Another modification of the AVM-1M device. The design of the device components is the same as in the AVM-1M, a third cylinder has been added.

Device AVM-5

Appearance of the device.

The appearance of the device is shown in Fig. 1.

1. Pulmonary demand valve (2nd stage of the regulator).
2. Headband.
3. Adapter.
4. Main air supply valve.
5. Clamps.
6. Shoulder straps.
7. Waist belts.
8. Cylinders.
9. Shoes.
10. Bracelet belt.
11. Remote activation of reserve air supply.
12. Reducer (1st stage of the regulator).
13. Backup air valve.
14. Lung demand valve hose.

The device consists of the following main components: a pulmonary valve (1) Fig. 1, a reducer (12), a cylinder with an angle (in Fig. 1 it is on the left), a cylinder with a valve (in Fig. 1 it is on the right), rubber cylinders are put on the bottom shoes (9), suspension system(6), (7) and (10), two clamps (5), a lung demand valve hose. The cylinders are connected to each other by an adapter (3), the tightness of the connection is achieved using rubber O-rings.

A reducer (12) is attached to the outlet fitting of the cylinder valve, connected by a hose (14) to the lung demand valve (1). The tightness of the cylinder-reducer-hose-automatic connection is achieved using rubber sealing rings of various diameters.

The cylinders are connected by two clamps (5) using bolts. Two crackers are installed between the cylinders, designed to provide a certain gap between the cylinders. On the right and left sides of the lower clamps there are buckles for attaching waist and shoulder belts. The shoulder straps are attached to the top clamp. A harness strap is attached to the bottom clamp.

A remote control for the reserve is attached to the side posts of the upper and lower clamps (11)

Technical characteristics of the AVM-5 device

The working pressure in the cylinders is 200 ati (there are modifications with PPAB = 150 ati).

The set pressure of the gearbox is 8 – 10 ati.

Reducer safety valve response pressure 10 – 12 ati

Bypass valve response pressure 40 – 60 atm

The capacity of the apparatus cylinders is 7 liters. (every).

Weight of the device in air with empty cylinders – 21 kg

Weight of the device in air with full cylinders – 24.5 kg

Scheme of operation of the device (stand-alone version).

The apparatus diagram is shown in Fig. 2

On the diagram:

1; 2; 3; 4 – gearbox parts.

5 – reducer safety valve.

6 – connection of the right and left cylinders (adapter).

7; 8; 10; 11 – parts of the backup air supply valve.

9 – bypass valve.

12; 13; 14; 15 – parts of the main air supply valve.

The main air supply valve (15) is open, the backup air supply valve (10) is closed, the device is charged to operating pressure.

When the valve (12) of the valve (15) is open, air from the left cylinder, bypassing the bypass valve (9), enters the reducer and then into the lung demand valve for the swimmer to inhale. For some time, the swimmer breathes air from the left cylinder (cylinder with a corner). When the pressure in the left cylinder is 40 - 60 ati (bypass valve adjustment pressure), less than in the right, the bypass valve (9) comes into operation. The valve opens under the influence of air pressure from the right cylinder, and air simultaneously from two cylinders enters the reducer. In this case, due to the operation of the bypass valve, a pressure difference of 40 - 60 ati will be maintained in the cylinders. The right cylinder (cylinder with valves) will have less pressure than the left one. During operation of the device, the pressure difference in the cylinders will be constantly maintained (due to the operation of the bypass valve). TO

When the pressure in the left cylinder approaches 0, the bypass valve, under the action of its spring, will begin to gradually close. In this case, the swimmer will feel resistance with each breath, increasing with each subsequent breath. Until the air in the left cylinder runs out, you can take 5–10 full breaths, then the air in the left cylinder will run out. Having felt the first signs of resistance while inhaling, you need to pull the remote reserve switch with your right hand (Fig. 7). In this case, the reserve air supply valve will open and air from the right cylinder (in which the pressure is 40 - 60 ati), through channels bypassing the bypass valve, will simultaneously flow into the left cylinder and will enter the reducer and be inhaled by the swimmer.

A characteristic sign of successful opening of the reserve air supply valve is the noise of air flowing from cylinder to cylinder, and the cessation of resistance when inhaling. When the pressure in the right and left cylinders is equal, the noise will stop. The pressure in the cylinders (if the bypass valve is adjusted to 40 ati) will be 20 ati in each cylinder, or (if the bypass valve is adjusted to 60 ati) will be 30 ati in each cylinder. Air for the swimmer to inhale will now be supplied simultaneously from two cylinders. Then, using this reserve air supply, the swimmer begins to ascend to the surface.

Scheme of operation of the device (non-autonomous version).

The air supply hose to the device is attached through a special fitting with a check valve; the fitting is cut into the corner of the left cylinder (not shown in the figure).

In the non-autonomous version, the left cylinder of the device works as a receiver (expander) for air. The right cylinder stores a reserve supply of air.

Air from the surface through a hose, under a pressure of 8-15 ati, is supplied to the left cylinder and then immediately to the reducer and inhaled. In the event of an emergency, the diver disconnects the air supply hose from the surface, opens the reserve and begins an emergency ascent to the surface.

The design of the AVM-5 apparatus does not include a high-pressure pressure gauge, which can be used to control the pressure (air reserve) in the cylinders during the dive.

1. When using the device, be sure to take a diving computer or watch underwater. Knowing at what depth you are swimming and the time, you can always approximately determine when approximately you need to open the reserve.
2. Never use unfamiliar (foreign) devices without first making sure that the backup air supply system is working properly.
3. Periodically, in the presence of a competent specialist, adjust and check the reserve.
4. Make an adapter and use an imported regulator with a pressure gauge complete with AVM cylinders.

I am attaching drawings of options (two options) for the AVM-5 adapter -DIN (300 bar).

Gearbox operation diagram.

The gearbox diagram is shown in Figure 4 and Figure 5.

1. Gearbox cover
2. Piston
3. Reducer spring
4. Sealing ring
5. Union nut
6. Gear housing
7. Adjusting nut
8. Sleeve
9. 10. 11. 12 Safety valve parts

When the main air supply valve is closed, the gear piston (2) under the action of the spring (3) is in the upper position. In this case, the gearbox valve is in the open position. When the main air supply valve is open, air passes through the filter and enters

into the cavity of the gearbox and into the hose of the pulmonary valve, at the same time, through the channel in the piston body, air enters the space above the piston. When the pressure in the space above the piston is equal to the spring adjustment pressure (reducer set pressure), the piston will begin to move downward and the spring will be compressed. A secondary plastic valve is pressed into the lower part of the piston. When the piston moves down, the valve sits on the seat. And air stops flowing into the gearbox cavity.

When the swimmer inhales, the pressure in the reducer cavity and above the piston space decreases, and again, under the action of the spring, the piston moves up and the valve opens.

There are holes in the gearbox housing. The holes are made in such a way that the gear spring is in the water. Consequently, not only the spring, but also water presses on the piston from below. Water pressure changes with depth. At a depth of 10 m. A column of water creates a pressure of 1 ati, 20 m – 2 ati, etc. Thus, at any immersion depth, the pressure in the gearbox cavity is 8-10 ati greater than the ambient (water) pressure.

If for any reason (malfunction, etc.) the pressure in the reducer cavity increases, then the safety valve comes into operation (adjustment pressure 10-12 ati). The activation of the safety valve serves as a signal that the gearbox is malfunctioning; it is necessary to urgently begin ascent to the surface.

Scheme of operation of a pulmonary demand valve.

The diagram of the lung demand demand valve is shown in Figure 6.

1. Lung demand demand valve cover with holes
2. Forced air button spring
3. Pulmonary demand valve membrane
4. Lever arm
5. Machine valve
6. Valve seat
7. Valve spring
8. Strainer
9. Exhalation valve
10. Lung demand demand valve body
11. Cover fastening clamp

When a diver inhales, a vacuum is created in the cavity of the lung demand valve. In this case, the membrane (4) moves down and with its rigid center presses on the lever (5), the lever, moving around its axis, presses on the machine valve, which warps, moves away from the seat (7) and opens access to the air flow from the hose and the gearbox cavity into the cavity of the pulmonary valve and to the diver for inspiration, through the mouthpiece.

When the diver exhales, the membrane (4) moves upward, stops pressing on the lever (5), the valve (6) sits on the seat under the action of its spring, and the access of air from the hose into the cavity of the lung demand valve stops. The diver continues to exhale, pressure is created in the cavity of the machine and the exhaled air is removed through the open (under pressure) exhalation valves into the environment.

From the outside, through the holes in the cover (1), water presses against the membrane (4). Consequently, at the moment of inhalation, air is supplied to the diver under ambient pressure.

Valve.

Structurally, the main and backup air supply valves are made in one housing (3) Fig. 8.

The valve body is screwed into the cylinder.

The design of both valves is similar, the parts are interchangeable. Only the location and design of the flywheels are different.

When the valve flywheel (15) Fig. 2 rotates, the rotation through the spindle (14) Fig. 2 and the block (13) Fig. 2 is transmitted to the valve (12) Fig. 2, which moves away or sits on its seat.

Working check of scuba gear.

When using any scuba gear, it is necessary to do a working check before each descent.

Conducting a work inspection does not take much time and does not require much effort. A properly performed operational equipment check will allow you to avoid many troubles.

1. Check the pressure in the cylinders.

To do this, it is necessary to attach a high pressure control gauge instead of the gearbox. Close the tap on the pressure gauge. Open the main and backup air supply valves. Read the readings on the pressure gauge. Then close the valve, open the tap on the high pressure gauge (bleed air from the pressure gauge), remove the pressure gauge.

1. Visual inspection.

A) Check the complete set and correct assembly of the scuba tank (fastening the gearbox, lung demand valve, clamps, belts, etc.), you can take the scuba tank by the straps and shake it lightly.

B) Adjust the straps

1. Leak test

With the valves closed, try to inhale from the lung demand valve. At the same time, the tightness of the membrane, exhalation valves, and connections is checked. Everything is fine if you can’t take a breath.

B) Wet.

Open all valves. Place the lung demand valve under the cylinder and lower the cylinder into the water. If there are air bubbles from under the connections, the scuba tank is faulty.

1. Checking the operation of the bypass valve (reserve).

Open the main air supply valve using the forced air supply button of the lung demand valve and bleed out some air (about 20-30 seconds). Next, open the reserve air supply valve. In this case, you should hear the characteristic noise of air flowing from cylinder to cylinder.

This test does not determine the amount of bypass valve actuation. After completing all the steps, you make sure that you have a working bypass valve in your scuba tank and, as a result, there is a reserve.

AVM-5 scuba adjustments.

1. Adjusting the set pressure of the reducer
2. Adjusting the response of the gearbox safety valve
3. Adjusting the lung demand valve
4. Adjusting the operation of the bypass valve (reserve)

Adjusting the set pressure of the reducer (8-10 ati).

1. Measuring the set pressure value.

Disconnect the lung demand valve.

Attach a control pressure gauge (0-16 ati) to the hose.

Close the tap on the control pressure gauge.

Open the main air supply valve.

Measure the pressure (8-10 ati).

Close the main air supply valve.

Open the tap on the control pressure gauge (bleed air)

1. Adjustment.

Unscrew the gearbox cover (1) Fig. 4

Pull out the piston (2) Fig. 4. To do this, screw a puller (or pick up a screw) into the threaded hole in the upper part of the piston and pull the puller. Then the piston can be easily pulled out. Using a screwdriver and trying to pry the piston by the edge is not recommended.

To increase the set pressure, it is necessary to compress the gearbox spring (3) Fig. 4

To reduce it, the spring must be weakened.

Two types of gearboxes were produced.

In the first case, to adjust the installation pressure, it is necessary to place or remove special adjusting washers under the spring (3).

In the second case, it is necessary to move the adjusting nut (7) along the thread of the bushing (8) Fig. 4.

In both cases, the meaning of all actions is to compress or decompress the spring (3).

Adjustment and measurement manipulations are carried out until the set pressure value is equal to 8-10 atm.

Adjusting the response of the safety valve (10-12 ati).

All operating instructions for AVM scuba gear recommend adjusting the operation of the safety valve at a repair and control unit (RCU).

The safety valve is screwed onto a special fitting on the RKU. Pressure is applied to the valve, and by the compression force of the spring (11) Fig. 5, the valve is adjusted to the desired pressure.

In practice, adjustment is performed in a slightly different way.

1. Adjust the reducer to the set pressure
2. Unscrew the locknut on the safety valve
3. Slowly rotating the valve body (12) Fig. 5 counterclockwise until the valve begins to operate.
4. Tighten the valve body (12) half a turn clockwise until the valve stops releasing air.
5. Tighten the locknut.

Thus, we will adjust the valve to an opening pressure that will be slightly higher than the set pressure (by 0.5-2 ati)

Adjusting the lung demand valve

The operating instructions for the scuba tank say that the lung demand valve cannot be adjusted.

In practice, adjusting the ease of breathing (inhalation resistance) can be done by bending the lever (5) Fig. 6. When bending the lever, the distance between the membrane (4) and the lever (5) Fig. 6 changes; the greater the distance, the greater the resistance when inhaling. It should be noted that if the lung demand valve is adjusted correctly, then when it is placed in water, air will randomly escape with the mouthpiece up. If the lung demand valve is turned with the mouthpiece down (as shown in Fig. 6), the air stops coming out.

Adjusting the operation of the bypass valve (reserve).

1. Measuring the pressure adjustment of the bypass valve.

When measuring this value, it is necessary to charge the device to a pressure of at least 80 ati.

Unscrew the gearbox and lung demand valve.

With the backup air supply valve closed, open the main air supply valve.

Vent the air.

When the air stops coming out, screw a high-pressure test pressure gauge (0-250 ati) to the fitting (instead of the gearbox).

Close the tap on the pressure gauge.

The pressure gauge should show 0 ati.

The pressure that the pressure gauge shows will correspond to the pressure of the reserve air supply.

Multiplying the resulting value by 2, we obtain the response pressure of the bypass valve.

The pressure of the reserve air supply should be within 20-30 ati, respectively, the response pressure of the bypass valve should be within 40-60 ati.

1. Adjustment

If the measurement results indicate the need for adjustment.

Bleed remaining air from the cylinders.

Loosen the clamps (5) Fig. 1

Loosen the union nuts of the adapter (3) Fig. 1 (you can use a gas wrench).

Move the cylinders apart and remove the adapter (3)

At the point where the adapter (3) is attached to the cylinder with valves, access to the bypass valve adjusting nut will open.

Compressing or releasing the bypass valve spring, using the adjusting nut, change the setting. If it is necessary to increase the adjustment pressure, then compress the spring (turn the nut clockwise); if to decrease it, release the spring.

1. Assemble the cylinder.
2. Charge up to 80 ati.
3. Take a measurement.
4. Repeat adjustment if necessary.

O-rings and lubrication of the device.

To ensure tight connections, the device uses rubber O-rings various diameters.

To prevent “drying out,” the rings must be lubricated. Technical petroleum jelly (CIATIM 221) or its substitutes are used for lubrication.

The ring to be lubricated must be placed in the grease, left for some time (5-10 minutes), then cleaned of excess grease and installed in place.

In addition, the device lubricates the rubbing parts of the gearbox (piston). Lubricant is applied and then excess is removed.

Frequency of device checks.

Operational check - before each descent.

Small check (checking all adjustments, lubrication of O-rings) - before the start of the season.

Full check (small check + complete disassembly and reassembly) - upon receipt from the warehouse, in case of doubt about serviceability, after long-term storage.

Device AVM-5AM

It differs from AVM-5 in that the device is made of non-magnetic alloys.

When used autonomously, the AVM-5 and AVM-5AM devices can be used in a single-cylinder version.

To convert to a single-cylinder version you need:

- bleed air from cylinders

- remove the cylinder mounting clamps

- remove the suspension straps from the clamps

— unscrew the adapter installed between the cylinders

— take the backrest from the spare parts kit (supplied)

- install suspension straps on the back

- attach the balloon to the back

— remove the plug from the left cylinder (cylinder with a corner) and install it on the right cylinder.

Device AVM-6

• The design of the main components is similar to the AVM-5 apparatus. The device is equipped with cylinders with a capacity of 10 liters.
• The mass of the device in air with empty cylinders is 23.8 kg.
• Weight of the device in air with full cylinders – 29 kg
• The working pressure in the cylinders is 200 ati.

Device AVM-7

It is similar in design and configuration to AVM-5. On the other hand, AVM-7 can only be used in a standalone version. The design of the device does not include check valve on the left cylinder.

Device AVM-8

The design of the main components is similar to the AVM-7 apparatus. The device is equipped with cylinders with a capacity of 10 liters.

Device AVM-9.

The appearance of the device is shown in Figure 1.

The main parts of the AVM-9 apparatus.

(1) and (7) cylinders

(2) carrying handle

(3) gearbox

(4) shut-off valve

(5) emergency switch

(6) protective cover

(7) balloon

(8) surface air supply hose

(9) lung demand valve

(10) lung demand valve hose

(11) high pressure pipeline

(12) tee with charging connection

(13) foam insert

(14) rubber shoe

(15) minimum pressure indicator with pressure gauge

AVM-9 is a universal two-cylinder device with two-stage scheme reduction. In the event of an emergency, when air is supplied through a hose from the surface, the design of the device ensures that the diver automatically switches to a reserve supply of air in cylinders. At the same time it is triggered light alarm(the signal light located on the minimum pressure indicator lights up).

Device AVM-10

The design is based on the AVM-7. The connecting threads of the adapter between the cylinders are made according to the DIN standard. Connection size gearbox mounting also corresponds international standard 5/8” DIN.

The design of the gearbox is based on the operating principle of the gearbox of the AVM-1M device. The gearbox housing has been modified. The reducer has a high pressure output for connecting a pressure gauge, and several medium pressure outputs for connecting the hoses of a lung demand valve, octopus, compensator, and dry suit.

The suspension system of the device has been slightly changed. The harness straps are attached to a plastic backrest, to which the cylinders are in turn attached. It is possible to use the device in a single-cylinder version.

Operating pressure of the apparatus cylinders is 200 bar

Device AVM-12

The AVM-12 apparatus set is one of the latest developments of KAMPO OJSC (142602, Orekhovo-Zuevo, Moscow region, Gagarina St., 1, tel. 12-60-37, fax 12-70-36.

The device is designed for compressed air diving to depths of up to 60 meters.

The kit includes a balloon block with suspension belts, a VR-12 air reducer, and a lung demand valve.

Balloon block with suspension straps

Cylinders of 7 liters with a working pressure of 200 ati are used. The appearance of the balloon block resembles the AVM-7. To connect the cylinders and connect the reducer, threads according to the DIN standard are used.

The suspension consists of a backrest and fastening straps. When working with buoyancy compensators, the suspension is removed and the cylinders held together with clamps remain.

AVM-12 can be converted into a single-cylinder version. The conversion is similar to the AVM-5 device; the delivery set includes a backrest for a single-balloon.

Air reducer VR-12

The appearance of the gearbox is shown in Figure 5.

Main characteristics of the VR-12 gearbox:

1. Gearbox set pressure 9.5 – 11 ati
2. Safety valve response pressure 14 – 17 ati
3. Gearbox weight, no more than 1.1 kg

The gearbox consists of the following main parts (Fig. 1):

1. Diaphragm pusher.
2. Dry chamber cover.
3. Dry chamber membrane.
4. Adjustment screw.
5. Main spring.
6. Gearbox housing cover.
7. Plate.
8. External pressure chamber.
9. Membrane.
10. Hard center.
11. Pusher.
12. Reducer valve seat.
13. Reducer valve.
14. Reducer valve spring.
15. Ring.
16. Guide bushing.
17. Bush spring.
18. Sealing ring.
19. Gearbox plug.
20. Valve stroke cavity.
21. High pressure chamber.
22. Gear housing.
23. Nut for fastening to the cylinder.
24. Union.
25. Sealing ring.
26. Air filter.
27. Medium pressure chamber.

Operating principle of the gearbox:

When the main air supply valve is closed, under the action of the main spring (5), the gearbox valve (13) is open.

When the main air supply valve is open, the air supplied to the gearbox enters the high pressure chamber (21) and through open valve reducer (13) into the medium pressure chamber (27). When the pressure in the chamber (27) equals the adjustment pressure of the main spring (5), the gearbox diaphragm (9) will begin to bend upward. Spring (5) will begin to compress under the influence of air pressure in the medium pressure chamber. The gearbox valve (13), under the action of its spring (14), will begin to move upward and sit on its seat (12). When the pressure in the chamber (27) increases to the set pressure, the reducer valve (13) will close completely.

When you inhale, the air pressure in the chamber (27) will decrease, and the main spring (5) will begin to expand. The force of the main spring through the plate (7), the rigid center (10), the pusher (11), will press the gearbox valve (13) from its seat (12). Air will again begin to flow into the high pressure chamber.

Between the membranes (3) and (9) there is a dry chamber designed to maintain the operation of the gearbox at low temperatures and in case of operation in contaminated water. The dry chamber prevents water and dirt from entering the gearbox membrane (9).

In the event of a malfunction, when the pressure in the chamber (27) rises above the set value, a safety valve is activated, adjusted to open at a pressure of 14 - 17 atm.

The safety valve is screwed into the medium pressure port of the reducer. If the reducer is used in conjunction with direct-flow imported lung demand valves, the safety valve does not need to be installed. Instead of a safety valve, a plug is installed.

Figure 2 shows the location of the medium and high pressure ports and the location of the safety valve.

1. Fitting for fastening to the cylinder block.
2. Safety valve (medium pressure port).
3. Medium pressure port.
4. High pressure port.
5. Medium pressure port.
6. High pressure port.
7. Medium pressure port.

The VR-12 gearbox has several modifications:

The cylinder fitting (1) has a DIN connection (230 bar), the medium pressure ports (2)(3)(5)(7) have a 3/8” UNF thread, the high pressure ports (4)(6) have a 7 thread /16” UNF

VR-12-2

Fitting for attachment to AVM-5 type cylinders (sleeve nut M#24#1.5), medium pressure ports (2)(3)(5)(7) have a 3/8” UNF thread, high pressure ports (4)(6) ) have a 7/16” UNF thread

VR-12-1

The cylinder fitting (1) has a DIN connection (230 bar), the medium pressure ports (1)(5) have a 1/2" UNF thread, the medium pressure ports (2)(7) have a 3/8" UNF thread, the high pressure ports pressure (4)(6) have 7/16” UNF threads.

Figure 4 shows the design of the VR-12-2 gearbox fitting.

1. Sealing ring.
2. Union nut with thread M#24#1.5 (АВМ-5).
3. Union.
4. Filter.

Adjustments of the VR-12 gearbox:

1. Adjusting the set pressure of the reducer

Attach a test pressure gauge to any medium pressure port and measure the set pressure.

Adjustment is made using the adjusting screw (4) Fig. 1

1. Adjusting the response of the safety valve.

Unscrew the cover of the dry chamber (2), pull out the membrane of the dry chamber (3), pull out the membrane pusher (1), with the main air supply valve open, press the plate (7) with the rod, and use the control pressure gauge screwed into the medium pressure port to measure the opening pressure of the safety valve . If necessary, loosen or compress the safety valve spring.

Pulmonary demand valve.

The lung demand valve included in the VR-12 regulator kit is shown in Figure 6.

The pulmonary demand valve consists of the following main parts (Figure 3):

1. Clamp fixing screw
2. Pulmonary demand valve clamp
3. Pulmonary demand valve body
4. Pulmonary demand valve valve spring
5. Pulmonary demand valve
6. Pulmonary demand valve valve seat
7. Pulmonary demand valve lever
8. Submembrane cavity of the pulmonary valve
9. Threaded fitting for attaching a mouthpiece, or attaching a diving suit to a helmet.
10. Valve for switching to breathing from the atmosphere
11. Lung demand valve cover
12. Pulmonary demand valve membrane
13. Forced air button
14. Pulmonary demand valve exhalation valve.

The principle of operation of the pulmonary demand valve of the VR-12 set is similar to the operation of the pulmonary demand valves of devices of the AVM-5 type. Maintenance and adjustment are also similar.

IN winter conditions at high consumption air, it is possible that an ice plug may form in the area of ​​the lung valve valve.

Ukraine device

The device is Ukraine in its design and appearance can be compared with the AVM-1 device.

The Ukraine device consists of two cylinders, each of which has its own valve. The cylinders are connected to the lung demand valve using a tee. The pulmonary valve operates on the principle of single-stage reduction. That is, the working pressure in the cylinders immediately decreases to ambient pressure. In AVM-1 and AVM-1M, the operating pressure in the cylinders is reduced in the reducer to the setting 5-7 atm, and then in the lung demand valve to ambient pressure. The Ukraine device has a minimum pressure indicator with a whistle. When the pressure in the cylinders decreases to the reserve level, each breath of the scuba diver will be accompanied by a whistle.

Ukraine-2 apparatus

Characteristic:

1. The working pressure in the cylinders is 150 ati.
2. The set pressure of the gearbox is 6-7 ati.
3. The response pressure of the gearbox safety valve is 9-11 ati.
4. The response pressure of the control valve (physiological reserve indicator) is 15-20 ati.
5. The volume of cylinders is 2 x 7 l.
6. The weight of the device in air with empty cylinders is 19.8 kg.
7. The weight of the device in air with full cylinders is 21 kg.

The appearance of the Ukraine-2 apparatus is shown in Figure 1.

The apparatus consists of two seamless steel cylinders (15), rubber boots (14) are put on the cylinders, allowing the apparatus to be placed in a vertical position, the cylinders are fastened together by two pairs of clamps (10), shoulder straps (9) are used to secure the cylinders on the diver’s back, waist (12) and shoulder strap (13), the straps on the diver's belt are fastened with a quick-release buckle (11).

A shut-off valve (5) with a reserve switch (parts 6 and 7) is installed on one of the cylinders (the right cylinder in the figure). The second (left) cylinder is connected to the shut-off valve using a connecting tube (1).

A gearbox (8) with a lung demand valve is attached to the valve fitting (parts 2,3,4)

Shut-off valve with transfer switch

The appearance is shown in Figure 2.

The shut-off valve on the lead lid is screwed into the neck of the cylinder. The design of the shut-off valve is similar to the shut-off valves of other domestic devices.

The valve consists of a flywheel (1), the flywheel is mounted on a valve stem (2), a nut (3), and a valve (5).

When the flywheel rotates clockwise, the rotation is transmitted to the valve and the valve, moving down the thread, closes the channel (6) supplying air from the cylinders.

The reserve valve is designed similarly to the shut-off valve, the only difference is that the reserve valve is opened using a rod (12). The rod turns the lever and then everything happens as in a regular valve.

The principle of operation of the reserve

At operating pressure in the apparatus cylinders, air through the open shut-off valve presses the control valve (7) and enters the reducer through channel (14). When the pressure in the cylinders equals the adjustment pressure of the spring (10) of the control valve, the control valve will begin to close and gradually cut off the air supply to the diver. The diver will feel increasing resistance as he inhales. Next, you need to pull the rod (12) and open the reserve valve. In this case, air will flow in addition to the closed control valve. The control valve spring is adjustable to a pressure of 15-20 ati. Adjustment is carried out using a screw (8).

Figure 2 shows the old modification of the Ukraine-2 apparatus. In newer modifications of the device, instead of a control valve plug (9), a fitting with a branch pipe was made for attaching a high-pressure pressure gauge.

Design and principle of operation of the gearbox

The first releases of the device were equipped with a reverse-acting piston gearbox. This gearbox is very rare, so we will not consider it.

The most widely used gearbox membrane type. The membrane reducer from the Ukraine-2 apparatus, without changes in design, was also used with the Young and ASV-2 apparatuses

The appearance of the gearbox is shown in Figure 3.

The gearbox is attached using a union nut (14) to the outlet fitting (13) Fig. 2 of the shut-off valve.

With shut-off valve closed:

The main gear spring (21) presses on the pressure plate (2) and the gear diaphragm (3). The diaphragm transmits the force of the main spring to the pusher (4), the pusher with its rod (6) presses on the gearbox valve (9), the valve overcomes the force of its spring (10) and moves away from the seat (5). Thus, when the shut-off valve is closed, the gearbox valve is open.

With the shut-off valve open:

Air from the cylinders through the mesh filter (12) and the open reducer valve (9) enters the cavity low pressure gearbox and through the fitting (1) into the lung demand valve hose. At the same time, air enters under the gearbox membrane (3). When the pressure in the gearbox cavity equals the set pressure to which the spring (21) is adjusted, the spring will begin to compress, the membrane will move upward and the gearbox valve (9) under the action of its spring (10) will begin to close, i.e. move up and sit on the seat. When the pressure in the cavity under the membrane equals the setting 6-7 ati, the valve will close. With the flow of air from the lung demand valve, the pressure in the reducer cavity will decrease, and the reducer valve will open again. Thus, the set pressure will be constantly maintained in the gearbox cavity.

The set pressure in the gearboxes of the Young and ASV-2 devices is maintained within 4.5-5 ati. Which is somewhat less than the set pressure in the Ukraine-2 apparatus. This is due to the shallower operating depth of these devices. Pressure adjustment is carried out using a spring (21) and an adjusting screw (20).

To prevent pressure build-up in the gearbox in the event of incorrect adjustment or malfunction, a safety valve is located in the gearbox housing. The safety valve bleeds excess air from the gearbox cavity into the environment. Valve response pressure 9-11 ati.

Air escaping from the safety valve serves as a signal that the gearbox is faulty. The diver must immediately begin surfacing.

The safety valve details are shown in Figure 3, positions (15), (16), (17), (18). The valve is adjusted using a spring (18).

The lung demand valve hose is screwed to the fitting (1) of the reducer using a union nut.

The design and principle of operation of a pulmonary demand valve.

The appearance of the pulmonary demand demand valve is shown in Figure 4.

The operating principle is similar to the operating principle of devices of the AVM-5 type. Pulmonary demand valves differ only in their design.

The pulmonary valve of the Young apparatus differs from the valve of the Ukraine-2 apparatus by the longer hose length.

The pulmonary valve of the ASV-2 device has an additional fitting for connecting the machine to a diving suit.

Adjustments of the Ukraine-2 device.

1. Adjustment of the set pressure of the reducer, 6-7 ati.
2. Adjusting the response of the gearbox safety valve, 9-11 atm.
3. Adjustment of control valve response (reserve), 15-20 atm.
4. Adjusting the position of the transfer valve lever. In the closed position, the lever should be at an angle of 20-30 degrees to vertical axis device, when open – vertically downwards.
5. Adjusting the ease of breathing in the lung demand valve. According to the instructions there is no such adjustment. In practice, you can use a file to slightly shorten the valve stem of the lung demand valve (10) Fig. 4, and the effort during inhalation will increase.

The practical implementation of adjustments on the units of the Ukraine-2 device is similar to the adjustments of devices of the AVM-5 type.

Apparatus ASV-2

The device is designed for diving to a depth of 20 m and for operation in an atmosphere not suitable for breathing.

ASV-2 is included in the kit emergency equipment civil courts and is used by fire crews when working in smoky rooms.

Literature:

V.G. Fadeev, A.A. Pechatin, V.D. Surovikin, Man under water., Moscow, DOSAAF, 1960

Handbook of a submarine swimmer (scuba diver). Moscow, Voenizdat 1968

Diver's Handbook. Under general ed. E.P. Shikanova., Moscow, Voenizdat, 1973

Light diving business., Merinov I.V., Moscow, Transport, 1977

Merenov I.V., Smirnov A.I., Smolin V.V., Terminological Dictionary., Leningrad, Shipbuilding, 1989

Merenov I.V., Smolin V.V., Diver's Handbook. Questions and answers., Leningrad, Shipbuilding, 1990

O.M. Slesarev, A.V. Rybnikov, “DIVING BUSINESS”, reference book, St. Petersburg, IGREK, 1996

Air reducer VR-12, passport, 9V2.955.399.PS, KAMPO

Features of hypothermia in water (clinic, treatment and prevention) Details of incidents with divers in 2007

translates as "water lungs" Creation components scuba diving happened gradually. First, a surface air regulator was patented, then it was adapted for use in scuba gear. The first successful underwater breathing apparatus using pure oxygen was invented in 1878. The first scuba gear was created in 1943 by the French Jacques-Yves Cousteau and Emile Gagnan.

Scuba gear can be one-, two-, or three-cylinder with air under pressure of 150-200 atmospheres. Typically, cylinders with a capacity of 5 and 7 liters are used, but if necessary, you can use cylinders of 10 and even 14 liters. They have a cylindrical shape with an elongated neck, which is equipped with an internal thread for attaching a nozzle or high-pressure tube. Cylinders are made of aluminum or steel. Steel cylinders must be covered protective layer, without which their outer part is subject to corrosion. Zinc is used as such a coating. Steel cylinders are stronger and less buoyant. Cylinders are filled with compressed and filtered air or a gas mixture. Modern cylinders have overfill protection. The scuba tank is equipped with a lung demand valve and straps for attaching to the human body.

All scuba gear are divided into three types according to the type of breathing pattern: with open, semi-closed and closed circuit.

If scuba operates on the principle of pulsating air supply for breathing (inhalation only) with exhalation into the water, then this is an open circuit. In this case, the exhaled air does not mix with the inhaled air and its reuse is excluded, unlike devices with a closed cycle.

In scuba gear closed breathing pattern Carbon dioxide is removed from the air exhaled by the diver and oxygen is added as needed. In this case, the same volume of air is used for breathing several times. Using this type of scuba gear, the diver is less visible to the inhabitants underwater world and does not scare them, since there are no bubbles of exhaled air.

At semi-closed scheme part of the exhaled air goes for regeneration, and part goes into water.

Breathing in scuba gear open type is carried out as follows: compressed air enters the lungs through a mouthpiece from a breathing machine, and exhalation is done directly into the water. To supply air, a regulator is used, which is connected to the outlet of the cylinder block. From each cylinder in turn air flows into the regulator through stop valves. Using a pressure gauge connected to the regulator, you can make sure that the cylinder is filled with air in accordance with the operating pressure, and by reaching back and turning the stop valves, you can find out how much air you have left in the cylinders.

The second stage of the regulator, the pulmonary (breathing) machine, converts the air leaving the first stage of the regulator to ambient pressure and supplies it to the human respiratory organs required quantity. Breathing machines are divided into two groups - with in-line and counter-flow valve mechanisms. Most modern scuba gear is equipped with a breathing apparatus with an in-line valve mechanism. The valve opens with a flow of air coming from the first foot during inhalation and closes the exhalation tube, and when exhaling, the inhalation tube. Thus, in closed-circuit scuba gear, the loss of clean air and the inhalation of already used air are prevented.

According to their design, scuba tanks are single-stage and two-stage, without separation of air reduction stages and with separation. Nowadays, two-stage automatic machines with separated reduction stages are used.

Scuba gear is a device for ensuring the breathing of a person underwater. The design of this self-contained breathing device consists of two compressed air cylinders, a breathing apparatus, and fastening belts.

The operating principle is based on automatically supplied air from cylinders, where it is in compressed form. Scuba diving was created in 1943 in France by scientists J. I. Cousteau and E. Gagnan. This device allows a person to stay under water at a depth of up to 40 m for several minutes and even up to 1 hour. Scuba gear is very widely used in rescue work, scientific research work taking place under water, as well as in underwater sports. For a longer stay of a person under water and lowering him to greater depths, special diving equipment is used. This equipment differs in the methods of supplying a person with a gas mixture and can be autonomous or non-autonomous. The breathing pattern can be ventilated, open, semi-closed and closed.

Composition of respiratory gas mixtures also varies and consists of air or oxygen, or a mixture of nitrogen and oxygen, or helium and oxygen. In addition to cylinders with a gas breathing mixture, diving equipment has a special waterproof shell, which is called a diving suit and reliably protects a person from the external environment. Such equipment appeared in many countries in the 1930s and 1940s, although attempts to immerse a person to a depth of even 30 m have been practiced since ancient times. But a person could survive under water without any equipment for more than 2 minutes, and even the use of a breathing reed tube could not increase the time a person spent under water. And only in late XVIII V. an air pump and diving equipment - a diving suit - were invented. In Russia, diving appeared already in 1882.

Modern diving equipment varies in design, which depends on the purpose. The method of air supply also varies. In the non-autonomous method, the diver breathes air supplied from the surface through a hose. But this limits the diving depth to 60 m and the maneuverability of the diver. Therefore, the offline method is more effective. The depth of the dive also affects the composition of the gas mixture: the air-oxygen mixture allows a person to descend to a depth of up to 100 m, the helium-oxygen mixture provides a dive of more than 100 m. Therefore, such diving
the equipment is used for rescue work and during construction or repair under water and is practiced in many foreign countries, especially in the USA, Great Britain, Germany, and France.

Further improvement of such equipment is aimed at improving the conditions for a person to stay under water and the efficiency of his work. New methods are being developed and new artificial gas mixtures are being created.

Before you start filming underwater, it is absolutely necessary to have a good grasp of the theory and practical exercises of underwater sports techniques. After the scuba gear, mask, fins and breathing tube become so familiar and natural that you stop feeling them, you can take up the underwater movie camera.

SUITABILITY FOR SCUBA DIVING

When talking about scuba diving, you should immediately distinguish between swimming and snorkeling from scuba diving. The first case is simpler and more accessible, but in the second case the operator, having turned into an amphibious man, receives immeasurably better opportunities for shooting.

Every person with healthy ears and heart is fit for scuba diving. Sometimes two circumstances interfere with the rapid mastery of this art: some fear of hydrophobia, as well as difficulty breathing through the mouth that occurs in some people (when scuba diving, they breathe only through the mouth). These obstacles can be overcome (and the first one is very easy) with practical exercises in snorkeling. The viewing glass of the mask gives a person confidence in the water, as it makes it possible to see the bottom and all surrounding objects. Since the mask also acts as a float, the beginner is quite surprised that he does not sink even when he does not make the slightest movement, and this gives him a feeling of confidence and security (Fig. 16).

Difficulty breathing through the mouth (which is quite rare) is explained. a purely nervous state caused by the fear of suffocation, since breathing in this case is not entirely free. Some people experience approximately the same thing in a gas mask. A few practice sessions with the breathing tube should dispel any fear. After this, the swimmer will feel good in the water when diving and breathe normally through the scuba mouthpiece. In domestic diving practice, another name for a breathing mouthpiece is common - a mouthpiece. This name comes from the fact that a rubber mouthpiece is inserted into the mouth and held in place by the teeth and lips.

BREATHING TUBE, MASK, FINS

The breathing tube provides breathing during swimming when the swimmer's face is under water. Moving with the help of flippers, he has the ability to view objects in the water through the glass of the mask. If necessary, the swimmer dives during the pause between inhalation and exhalation.

The simplest breathing tube consists of two parts: an aluminum, plastic or rubber (elastic) curved tube and a mouthpiece, i.e. an elastic mouthpiece connected to the lower end of the tube to hold it in the teeth.

Typically, the length of the tube does not exceed 450 mm with an internal diameter of 15-22 mm and has a volume of 100-200 cm3. The weight of the tube ranges from 80 to 300 g (Fig. 17).

Rice. 17. Valveless breathing tube: 1 - tube; 2 - front mouthpiece shield; 3 - mouthpiece; 4 - “snacks” for holding the mouthpiece with your teeth; 5 - lips; 6 - teeth; 7 - language

The design of the tube is so simple that it is easy to make it yourself.

The simplest snorkel is preferred by experienced divers to everyone else and is the main sporting type of snorkel.

More complex in design are breathing tubes with automatic ball- or float-type valves that prevent water from entering the tube (Fig. 18). The operation of automatic valves is that a light cylindrical ball, or float, floats up and blocks the access of water inside the tube. Such tubes are used by beginners who do not yet have the skill to use a more convenient simple tube.

There are breathing tubes in combination with a mask. The principle of their design is the same as that of tubes with an automatic valve, but when used, inhalation is done through the nose, since the mouth is located outside the mask. Such tubes are less convenient, and we do not recommend them for underwater film enthusiasts.

The importance of breathing tubes in underwater sports cannot be overestimated. In addition to simplicity and ease of use, they make it possible to set your own breathing mode under various loads and acquire a conditioned reflex in closing respiratory tract when water enters the tube.

The breathing tube must be in the scuba diver's belt. It may not be needed on ten, fifteen or even twenty dives, but on the twenty-first dive the breathing tube will save his life.

Underwater, a scuba swimmer feels calm and confident. But when he rises to the surface, he is nothing more than a swimmer laden with heavy equipment. If he floats far from his base (boat or shore), having used up all the air in his cylinders, and if there is also a slight swell at sea, the situation may turn out to be threatening. In this case, the diver begins to get tired quickly, especially since due to the equipment he is not as free in the water as an ordinary swimmer. Therefore, instead of using scuba gear, he is forced to use a breathing tube, which rises sufficiently above the water. Then the swimmer is not in danger of choking, and he calmly returns to his base, without fear of exhaustion.

Therefore, one of the basic rules of scuba diving is the obligatory presence of a breathing tube, regardless of whether you are going to dive to deep or shallow depths, close or far from the shore.

The second very essential accessory for a swimmer is a mask (Fig. 19). It serves to protect the eyes from the surrounding water and thereby provides the swimmer with the ability to see in clear water. Separate breathing and vision equipment is a reliable guarantee of safety. If the mask leaks or fills with water, the swimmer will continue to breathe normally through the mouthpiece. He can either float up, holding his nose (if the mask has fallen off or the glass has broken, which has not yet happened in practice), or, if the mask is in place, but filled with water, calmly remove the water.

The design of the mask is simple: it consists of an oval or round viewing glass, a rubber base, a metal tightening rim and a back strap or headband, which is secured to the upper part of the face.

A regular mask has a window made of flat, unbreakable glass, which changes the perception of distance and increases the size of objects. This is due to the higher refractive index of water (1.33) compared to air. Therefore, under water, the bottom usually seems closer than it actually is. In reality, such an increase in objects does not have of great importance, since you stop noticing it after the first attempt to swim with a mask.

The enlargement of objects is felt only when a familiar object (for example, a bottle, a jar) comes into view.

To have a normal image under water, in a number of countries they use a special correction mask with two windows, into each of which a convex and a concave lens is inserted (Fig. 20). Lenses eliminate distortion of shape and distance and increase the field of view. A corrective mask makes it possible to see objects under water in their natural size, but in the air it distances and distorts objects. Therefore, this distortion must be taken into account when entering and exiting the water.

The mask allows you to dive to any depth and swim on the surface. This explains its versatility and widespread use among athletes. The mask, like the breathing tube, is easy to make yourself.

The third element necessary for scuba diving is fins. They serve to increase swimming speed and maneuverability under water. In addition, fins extremely save the swimmer's strength.

IN given time There are several dozen varieties of fins known, but they all have, in principle, one device and one purpose. However, the degree of elasticity of weasels is the main criterion for assessing their quality and allows all fins to be divided into three types: elastic, normal and hard.

Practice has established that the efficiency of elastic fins is significantly inferior to normal ones, and even more so than rigid ones. Normal fins are good to use for long-term swimming and long distances, since this uses the swimmer’s strength more efficiently.

Athletes prefer hard fins when swimming short distances with maximum speed, as well as when it is necessary to increase maneuverability.

In this case, the athlete’s strength is most fully spent in a short period of time.

Well-chosen fins make it easier for a swimmer to maneuver in the water, increase the speed of movement, and free up his hands for filming.

SCUBA

The most remarkable quality of scuba gear is that it allows a person to swim underwater at various depths and in any position without any additional adjustment. The device automatically adjusts the amount of air supplied to the lungs depending on the depth of the dive. Thanks to scuba gear, a person underwater seems to acquire second lungs, specially adapted for breathing in water, and does not feel constrained by anything.

The body is freed from the need to be only in a vertical position, as is the case on the ground. At will, a person can dive deep into the depths or float to the surface.

Having such accessible and relatively safe equipment, we can talk about its widespread use in underwater filming.

The peculiarity of this device is that it is filled not with oxygen, but with compressed air. In scuba gear, an open breathing system is used: the air exhaled by a person, without being held anywhere, comes out (Fig. 21).

Thus, the human lungs are constantly supplied from cylinders. Fresh air. The use of compressed air completely eliminates the possibility of oxygen starvation, carbon dioxide poisoning or oxygen poisoning. The advantage of scuba gear over other diving devices is its simplicity in design and operation, as well as its readiness for immediate action? immediately after opening the cylinder valves.

How does scuba work?

Its main parts are: a lung demand valve, steel cylinders for storing air compressed to 150-200 atm, two corrugated rubber hoses, a mouthpiece and a belt system for attaching the device to the body.

The pulmonary demand valve is the main and most important part of the apparatus. Its task is to reduce the pressure of the air in the cylinders to the pressure of the outside environment and supply it to the human lungs in a timely manner and in the required quantity. The lung demand valve is activated human lungs, due to which its work is automatically coordinated with the rhythm of breathing: air is supplied to the lungs only during inhalation, and during exhalation the supply stops. The lung demand valve is connected to the cylinders and to the mouthpiece via two corrugated hoses, one of which is used when inhaling and the other when exhaling.

The most common domestic scuba gear is “Podvodnik-1” (factory brand AVM-1), produced by the “Respirator” plant of the Moscow Regional Economic Council (Fig. 22).

Rice. 22. General view of the scuba gear “Podvodnik-1”

In this device, air, compressed to 150 atm, is stored in two cylinders, fastened into a cassette with two clamps. The capacity of each cylinder is 7 liters. Thus, the total air supply at full pressure is about 2100 liters.

A two-stage pulmonary valve is connected to the cylinders.

The device is attached to the diver's back using a set of straps - two shoulder straps, a waist strap and a lower strap, which, when put on, are connected to each other with one easily detachable buckle. The equipment set for the device includes a mask and a weight belt.

A weight belt is a belt with an easy-to-release buckle to which lead weights are attached. The amount of weight can be different (the set includes 14 weights weighing 0.5 kg each) and is selected so that the athlete is in a state of neutral (zero) buoyancy or slowly sinks. Typically, weights have to be used only when swimming in wetsuits.

The weight of Podvodnik-1 with filled cylinders is 23.5 kg, and under water - 3.5 kg, i.e. the device pulls the swimmer to the bottom. To avoid this, you can attach a piece of foam, a rubber football inner tube, or another object that is lighter than water to the machine. In the modernized Podvodnik-1 (factory brand AVM-1M), this drawback is eliminated, and factory-made foam plastic is added to the cylinders to compensate for the weight.

The permissible diving depth in scuba gear is 40 m. Diving deeper* is not recommended to avoid possible violation vital functions, known as “nitrogen intoxication”. Is it not recommended for the same reason? dive several times a day and use more than two cylinders per day.

It is known that the amount of air consumed varies depending on the pressure of the environment: as you dive for every 10 m, it increases by approximately 1 atm. Therefore, the duration of scuba diving depends on the depth of the dive.

On the surface or at a depth of up to 1 m, the average duration of stay under water in the Podvodnik-1 scuba gear is practically about 70 minutes, at a depth of 5 m - 50 minutes, at 10 m - 30 minutes, at 20 m - 20 minutes, and finally , at a depth of 40 m - about 3-10 minutes.

These time standards should not be taken literally, since they depend on the following two factors:
1) on the amount of air absorbed during breathing, which is different for different people; many underwater swimmers, after some training, learn to regulate their breathing and perform miracles of economy, using every cubic centimeter of air to the full;

2) on the number of muscular movements during scuba diving; A diver who is stationary or moving slowly uses less air than someone who is active in the water or doing heavy work.

The schematic diagram of the Podvodnik-1 scuba gear is shown in Fig. 23. It consists of two systems: high and low pressure.

The high pressure system includes cylinders, connecting air ducts, a minimum pressure indicator 17 and a pressure gauge 16. The low pressure system starts from the lung demand valve valve 7 and ends with the mouthpiece through which breathing is performed.

When you inhale through the mouthpiece, a vacuum is created in the lung valve chamber. The difference between the external pressure and the pressure in the lung demand valve chamber causes the membrane 1 to bend down. In this case, the membrane turns lever 2 clockwise relative to axis 5. Lever 2 turns lever 4 relative to axis 5 counterclockwise. Lever 4, when moving, presses the screw 6 screwed into it onto the valve stem 7 with a rubber cushion. Valve 7 departs from the seat of the pulmonary demand valve, and the air, passing from the gearbox chamber into the chamber of the pulmonary demand valve, is throttled to external pressure and enters the human respiratory organs through the inhalation hose.

After inhalation is complete, the vacuum in the lung demand valve chamber stops and membrane 1 stops pressing on levers 2 and 4. Valve 7, under the force of spring 8 and the air pressure under the valve, will close the hole in the lung demand valve seat. The pressure in the submembrane cavity will become equal to the external pressure, and the access of air from the reducer to the lung demand valve will stop.

Exhalation is carried out through a hose that ends with a petal valve. The air, passing through the slits of the petal, rushes into the supra-membrane space of the pulmonary valve and then, through the holes in its lid, enters the water, rising in the form of bubbles to the surface.

Simultaneously with the operation of the pulmonary valve, the gearbox also comes into operation.

Rice. 23. Diagram of scuba gear “Subvodnik-1”

Through an open valve, compressed air from the cylinders enters through a high-pressure pipeline system under the gearbox valve 9, lifts it and flows into the gearbox chamber. At the same time, the pressure in the gearbox chamber increases. As soon as it reaches a value of 5-7 atm (the so-called set pressure), the membrane 14 bends upward, carries the rod along with it and turns the lever 11 associated with it clockwise around the axis 12. In this case, one arm compresses the spring 10, and the other presses through the pusher 13 onto the gearbox valve 9 and presses it against the seat, thereby stopping the flow of air into the gearbox chamber.

This cycle is repeated in accordance with the rhythm of breathing.

In the reducer chamber, and therefore in front of the valve of the lung demand valve, an excess air pressure relative to the external one is automatically maintained within the range of 5-7 atm.

To prevent the air pressure in the reducer chamber from increasing above the set value, a safety valve 25 is provided, which releases excess pressure to the outside. The safety valve comes into operation when the tight seal of the gearbox valve 9 to the seat is broken, which can happen both during operation and during storage of the device.

Simultaneously with the flow of compressed air under the gearbox valve 9, it also flows to the pressure gauge 16 and the minimum pressure indicator 77, which serves to warn the scuba diver about the need to go to the surface. Underwater, it is possible to control the air pressure in the cylinders using a pressure gauge (in clear water) or by probing the minimum pressure indicator rod (in muddy water). If the air pressure in the cylinders has decreased to 30 atm and the indicator rod 18, under the action of the spring, takes an extended position with a characteristic click, the scuba diver must go to the surface, since the air in the cylinders remains for several minutes of operation of the device. To bring into working condition indicator of the minimum pressure 17, it is necessary to press the button of the rod 18 all the way and only then open the cylinder valves.

In addition to this method, there are sound indicators of minimum pressure to notify the scuba diver about the need to rise to the surface. This indicator in the form of a whistle is used in the “Ukraine” scuba gear produced by the mine rescue equipment workshops in Lugansk. This device is also based on the principle of pulmonary-automatic action with an open breathing system. The supply of air compressed to 200 atm in the “Ukraine” scuba tank is contained in two cylinders with a capacity of 4 liters each and thus amounts to 1600 liters.

The diagram of the scuba tank “Ukraine” is shown in Fig. 24. The minimum pressure indicator is combined in one block with the lung demand valve. It works as follows. When inhaling, compressed air from the cylinders enters the chamber of the pulmonary valve and at the same time under the diaphragm 1 of the minimum pressure indicator. Spring 2 is in the Compressed position, and rod 3 is in maximum height, keeping connecting tube 4 cocked.

Rice. 24. Scuba scheme “Ukraine”

As air is consumed, the pressure in the cylinders, and therefore on diaphragm 1, decreases. In this case, rod 3, under the influence of spring 2, goes down and, at a pressure in the cylinders of 35-40 atm, releases tube 4, which connects the outlet of the lung machine with whistle 5.

In this position, each breath of the scuba diver will be accompanied by a sound signal - this means that it is time to go to the surface.

CHARGING SCUBA WITH AIR

The device can be charged with air either directly from a high-pressure compressor (150-200 atm) equipped with a filter, or from transport (40-liter) cylinders previously inflated through a filter. Since a special compressor has not yet been created for underwater sports, in practice a field carbon dioxide charging station (FZUS) is used to charge scuba cylinders. This is a relatively bulky compressor unit portable type with a high pressure compressor AK-150 (Fig. 25). Such a compressor unit can charge a Podvodnik-1 scuba tank with air with two cylinders with a capacity of 7 liters each up to 150 atm in 50-60 minutes.

It is advisable to charge transport cylinders with compressed air from high-pressure compressors of higher capacity. For this purpose they can be used compressor stations AKS-2 or AKS-8, which are towed by a truck on a special two-axle trailer.

Charging scuba cylinders with air from transport cylinders is carried out according to the scheme shown in Fig. 26. In this case, three transport cylinders are usually used in order to more full use the air they contain.

Transport cylinders charged with air up to 150 atm are connected using spiral tubes to a KN-type oxygen pump, which, in turn, is connected to a filter, in in this case OKN-1.

After the circuit has been installed and tested, for charging you need to open the valves on the apparatus cylinders, the first transport cylinder, the compressor star and the filter output star. In this case, the air in the transport cylinder under a pressure of 150 atm, passing through the compressor, goes through the filter cooling coil into the moisture separator, then into the adsorber and ceramic filter. After the ceramic filter, the air flows through the outlet star into the filling cylinders of the device until the pressure in the entire system is equalized. The onset of this moment must be monitored by the pressure gauge on the compressor star and the filter star. The cessation of the hissing of the bypass air is also a sign that the pressure in the apparatus cylinders has become the same as the pressure in the transport cylinders and will be below 150 atm. The air pressure in scuba cylinders is increased to 150 atm using a KN oxygen compressor or a PZUS installation.

It should be noted that using a KN compressor you can increase the pressure no more than twice as compared to the pressure remaining in the transport cylinder.

If it was not possible to bring the pressure in the scuba tank to 150 atm from the first transport cylinder, you should switch to the second transport cylinder, and then to the third. In this case, transport cylinders with high pressure are used last. Once the pressure in the transport cylinders has dropped so much that it makes no sense to pump them further, you need to replace them with full ones. By the end of charging, the scuba cylinders heat up somewhat, but after some time they cool down, as a result of which the pressure in them decreases by about 10%.

Subsequently, if necessary, the apparatus cylinders can be recharged to a full pressure of 150 atm.

To clean the air from mechanical impurities, water and oil, an oil separator is provided on the compressor unit. It is a steel cylinder with a drain valve.

The principle of operation of the oil separator is as follows: air entering the oil separator cylinder changes its direction, as a result of which oil particles and other particles contained in the air settle to the bottom of the cylinder and, as they accumulate, are removed through the tap. The purified air exits through the opposite fitting.

In addition to such a filter, you need an activated carbon filter to clean the air from foreign gases.

It should be remembered that scuba cylinders must be filled completely clean air, i.e. free from any impurities (carbon oxides, lubricating oil vapors, their oxidation products, foul-smelling substances, etc.).

The most dangerous is the content in the air carbon monoxide(carbon monoxide), which is large quantities found in the exhaust gases of engines driving the compressor. Even a small amount of carbon monoxide in the air can cause swimmer poisoning. Therefore, air quality must be given particular attention.

To purify the air from impurities, a portable filter OKN-1 is successfully used, designed to purify and dry oxygen from moisture (Fig. 27).

To do this, the alumina (desiccant) in the filter adsorber is replaced with ordinary activated carbon, which is used in gas masks. The OKN-1 installation has dimensions of 480 x 500 x 240 mm and consists of a moisture separator, an adsorber, a ceramic filter and an output star.

Dehumidifier is designed to free the air from condensed moisture. It works on the same principle as the PZUS oil separator.

The adsorber is used to clean the air from gases and is a small-capacity cylinder4 filled with activated carbon.

The ceramic filter is used to clean the air from activated carbon dust. Its body is made in the form of a glass into which a ceramic cylinder is inserted.

The OKN-1 filter reliably cleans the air of harmful impurities, except carbon monoxide.

Some athletes successfully use a homemade filter (Fig. 28).

Rice. 28. Scheme and dimensions of homemade

filter: 1 - Activated carbon; 2 - adsorber; 3 - mesh

AUXILIARY EQUIPMENT

A handheld depth gauge is required when diving to great depths or in cases where the dive site is completely unfamiliar. It is very important that the depth gauge has divisions greater than 40 m. If the divisions end at 40 m, then in this case it is not clear whether you have dived to 40 m or much deeper.

There are two types of depth gauges: mechanical and pneumatic. A mechanical depth gauge is similar in design to a conventional pressure gauge and is based on the principle of water pressure in a curved tube of the device connected to a pressure gauge.

The pneumatic depth gauge is based on the principle of elasticity and incompressibility of water. Water entering the narrow channel (capillary) of the depth gauge compresses the air in it in proportion to the depth of immersion. The boundary between air and water stands out well against the black background of the scale and shows the depth in meters.

A swimmer needs a watch because subjective feelings time under water differs from normal - time under water goes faster. In addition, the watch helps determine the time spent under water and the time before rising to the surface. In addition to specially manufactured underwater watches, ordinary wristwatches enclosed in a sealed case are used for scuba diving.

A knife is not a weapon of defense, since, according to veterans of underwater sports, not a single sea creature attacks a person, but it is necessary to have it just in case. A knife is needed, for example, to quickly cut a tangled signal end, a cable or a fishing net that a swimmer might get caught in, as well as for many other unforeseen accidents under water.

The knife can be floating. This knife is convenient for a diver with a mask, who, if lost, can easily find it on the surface of the water. But for a scuba swimmer this is completely unprofitable, since when the knife floats to the surface, you need to follow it and then dive again. But for a diver, such frequent changes in pressure are harmful.

The wetsuit serves to protect the swimmer’s body from the effects of the surrounding aquatic environment, mainly from low temperatures. In the southern seas at the height of summer, you can briefly dive even to 40 m without a protective suit.

But already at a depth of 20 m, the cold is quite difficult to bear, especially for thin people. And despite the fact that protective clothing is up to to a certain extent restricts the athlete’s movements, it significantly lengthens the season of staying under water in southern reservoirs and ensures diving in northern reservoirs at a water temperature of +6...+8°. To do this, a set of warm (woolen) underwear, fur socks, a woolen cap and gloves are usually worn under the wetsuit.

The main requirements for protective clothing are: reliable insulation of the body from cooling with water; freedom of action under water for arms, legs and body; ease of dressing and undressing; absence of rough seams, fasteners, buttons and other parts that can cause abrasions on the body when moving underwater; low weight and volume.

The athlete must have heat-protective clothing that strictly corresponds to his height. You should not wear wetsuits that restrict movement or are too spacious, as air will be trapped in their folds, which will make it difficult to go into the depths.

The correct fit of the suit determines the success of the dive.

There are known suits made of sponge rubber and worn on a naked body. Although they are not waterproof, little or no water gets into the suit.

Some costumes are two-piece; others take the form of a jumpsuit with long or short sleeves and pants with a zipper. These costumes are easy to put on by yourself, without outside help.

Waterproof suits made of thin rubber are good (Fig. 29), under which they wear warm underwear. The suit can consist of a shirt and pants connected at the waist, or it can be a one-piece jumpsuit with an elastic collar through which you have to get into the suit. These impermeable suits are very good protective agent, but they are sensitive to pressure and at depth can squeeze the swimmer unpleasantly.

UNDERWATER VEHICLES

An underwater aquaplane (underwater plane) is a light board 60-70 cm wide and 20-25 cm long with a handle, which the athlete holds on to while in a horizontal position. The underwater aquaplane is towed by a boat (Fig. 30).

An underwater aquaplane is both a depth and direction rudder. Starting from the minimum speed of the boat and ending with 4-5 km/h, a swimmer, when moving behind an aquaplane, can develop strength, agility and orientation under water. By attaching a movie camera to the aquaplane and moving the control stick out, the underwater swimmer will be able to shoot in motion.

An underwater sled is used to tow a scuba diver with a movie camera along the bottom, which has a flat topography. To avoid sudden shocks, the sled must be quite massive.

An underwater bicycle (aquaped) is used to move an athlete underwater. It is a convenient sports apparatus and has buoyancy close to zero. Two propellers with a diameter of about 500 mm, rotating in different directions, or one propeller with a diameter of 700 mm are driven by pedal rotation. In Fig. Figure 31 shows one of these devices.

An underwater scooter, among other means of transportation under water, received greatest distribution. In appearance, it resembles a small torpedo with one or two propellers driven by an electric motor. The power source is rechargeable batteries. The propellers can be located both in the stern and in the bow of the scooter with a corresponding change in the direction of rotation. The swimmer holds on to the frame in the stern and by turning his body and especially his legs with fins gives the scooter the desired direction of movement. The scooter can carry film equipment, as well as underwater lights.

In this sense, the underwater scooter designed by cinematographer A.F. Leontovich is interesting (Fig. 32 and 33). The scooter has a length of 235 cm, a diameter of 40 cm and a weight of 150 kg. Its underwater speed is from 2 to 6 km/h. Electric motor power 800 W. The power source is a dual block of silver-zinc batteries STs-45, which provides total capacity 90 a-h. The tightness of the housing at the point where the propeller shaft exits is ensured by gland seals. The design uses standard ball bearings. The speed switch has five positions and is mounted in the form of a lever on a common handle. Case material - steel. The scooter has a negative buoyancy of about 200-300g. To ensure emergency ascent, a safety weight is used, which is separated using a handle.

One of the following equipment can be mounted on the scooter: a) a spotlight for search work or for illumination when filming with a movie camera from another scooter; b) “Konvas-automatic” movie cameras with 60 cassettes; c) a container with batteries and two lighting lamps with their activation on a common control knob. A flat mirror can be mounted in the nose of the scooter for “drive by” photography.

Several modifications of the scooter are known abroad, named after its designer (Rebikov’s film torpedo - Fig. 34), and a number of designs of large scooters capable of carrying several swimmers in addition to film equipment.

An underwater vehicle (aquakeb) is an ultra-small sports submarine with a waterproof hull. Its crew is wearing underwater sports equipment. The underwater vehicle allows you to move at speeds of up to 3-5 km/h with a pedal drive and up to 7 km/h with the help of an electric motor. All controls for this device are located on the steering wheel. The necessary stability and buoyancy of an underwater vehicle is achieved using solid ballast. The swimmer’s head is protected from the oncoming resistance of the water by a folding plexiglass shield (Fig. 35).

Floating base - this is what operator F. A. Leontovich called another design, which he created together with a team of designers led by engineer D. M. Brylin.

In appearance, the floating base resembles a double boat - a catamaran (Fig. 36) and consists of two streamlined aluminum pontoons, between which the cargo area is located. To ensure unsinkability, the pontoons are divided into sealed compartments.

Dimensions of the floating base: length 5 m, width 3 m, pontoon height 65 cm, draft 25 cm. Total weight the base is 150 kg, the load capacity is about 2 tons. The “Moscow” motor is suspended from the base area. The floating base has a ladder for lowering the scuba diver into the water, as well as a suspended underwater platform from which filming is carried out. To lift and lower the film camera overboard, the base is equipped with a special lifting boom.

BASIC RULES FOR SWIMMING UNDERWATER

A cinematographer's underwater capabilities are largely determined by his equipment.

With a breathing tube, mask and fins, the swimmer can shoot downwards while moving along the surface of the water.

A cameraman equipped with scuba gear can stay underwater for a long time and swim in any direction. Having equipped itself with weights for stability, it can move on the ground.

How to put on equipment? Lightly wipe the inside of the mask glass. Then rinse the mask in water and put it on. The fins must be pre-moistened so that they can be easily put on your feet. If you are wearing wetsuits, the inside of the fins should be moistened with soapy water. Soapy water will also help when pulling the tight rubber cuffs of the diving suit onto your hands.

Put on wetsuits slowly, trying to avoid the formation of wrinkles and cavities with air.

The scuba gear on the back should be secured tightly, without sagging, the straps should be well tightened. The presence of a lower (breaststroke) strap during swimming is mandatory, as it reliably holds the apparatus from distortion.

Descent into the water. To get into the water, it is best to have a convenient portable ladder (ladder) that can be used both from the pier and from the side of the boat. However, you often have to do without a ladder.

In any case, it is unsafe to jump into the water, since when hitting the water, the cylinders can become dislodged, and the diver runs the risk of being hit in the back of the head by a lung machine gun. In addition, during a sudden entry into the water, the mask may be removed from the face.

When descending from an open boat, sit on board with your back to the water, tilt your head towards your bent knees (i.e., curl up) and gently tip back, holding the mask with your hands. This fast and safe diving method has been tested in many underwater expeditions. When diving from a pier or from a steep shore, you should do things differently. Sit facing the water, dangle your legs, and then turn in a circle, transfer your weight to both hands and lower yourself into the water as smoothly as possible.

Before going into the water, do not forget to put a mouthpiece in your mouth. Many beginners forget to do this. If you go into the water and forget about your mouthpiece, don’t be alarmed. While remaining on the surface, remove water from the corrugated tubes by vigorously blowing air into the mouthpiece.

No matter how many swimmers accompany you in the water, someone must remain on the shore or in the boat as a belayer. He is the one who should give you an underwater film camera or lighting device into the water.

Take the equipment only after you are in the water and make sure that everything is in order and the scuba gear is working properly. Before starting systematic dives in a group, all scuba gear should be distributed to each diver in order to properly adjust, care and know the features of each device.

If the film camera has removable planes - wings, and under water you will have to move at high speed in tow (behind an underwater aquaplane or towing vehicle, behind a fishing trawl, etc.), then the wings should be removed in advance, since at the slightest angle of inclination of the film camera they will create large hydrodynamic resistance, the force of which will twist the device out of your hands. For working at high speeds (up to 6 km/h), film cameras are convenient, enclosed in streamlined spherical boxes mounted on the towing vehicle before filming begins.

Towing a scuba diver in normal equipment at a speed above 6 km/h is not recommended, since the increased resistance of the aquatic environment makes it impossible to control the underwater movie camera, rips the mouthpiece out of the mouth, compresses the corrugated breathing tubes, or simply rips the swimmer off the aquaplane or trawl.

Movement underwater. You don't have to be a good swimmer to move underwater. A mask, fins, and especially scuba gear give an extraordinary feeling of safety in the water, and a person feels like a fish. To move around, just move your legs slowly in a crawl style.

When swimming with a mask on the surface and breathing through a snorkel, you should carefully observe what is happening in the water. As soon as something interesting appears in your field of vision, you need to pick up speed, while breathing quickly and very deeply so that the blood is saturated with oxygen. Then, during one of the exhalations, which should not be done all the way (you need to leave some air in the lungs in order to blow out the water that got into the tube when ascending), you need to dive head down, continuing to work with your legs. In this case, you should try to make gentle movements and disturb the water as little as possible.

With training, you can bring the diving depth to 7-8 m. You should not go deeper without scuba gear.

When scuba diving, movements should also be slow. Remember that you inhale and exhale through the same small hole in the mouthpiece. Therefore, it is necessary to avoid a sudden transition to rapid breathing, as it can lead to suffocation. Moreover, you should train to remain motionless underwater for as long as possible, which is necessary to improve filming conditions.

It is desirable that the film camera in water has zero buoyancy. In this case, it will be quite easy to manage. However, small deviations in one direction or another do not matter much.

For underwater filming, it is best to look for places with a rocky bottom, as they are the most expressive and the water there is more transparent.

When exploring a wreck or a cramped underwater cave with a movie camera, always be aware of the corrugated breathing tubes that are located behind your head. Sharp, protruding parts may be damaged if they come into sharp contact.

Before entering any narrow passage, it must be carefully examined. Such examinations should be done by at least two people.

Exit from the water. First, hand the movie camera on board the boat or into the hands of a comrade standing on the gangway. Then, having first removed the breathing tube from your belt and handed it over, remove the scuba gear while holding the mouthpiece in your mouth. There is no need to take off your fins; they make getting out of the water easier. The mask is removed last.

This article is not an attempt to retell well-known facts or create another article similar to each other.

The task is to form an unambiguous and transparent understanding of the structure and principles of operation, one of the main elements of equipment for diving.

For me personally, for a long time, there was just a rough understanding of the basics of how a diving regulator works, and this is not correct.

Knowledge general principles construction and basics of work will allow you to take a more meaningful approach to choosing this element of diving equipment.

When we say "" we mean that it is part of a self-contained light diving equipment.
To avoid confusion, it is worth saying that there are two types of light diving equipment - those using closed and open breathing patterns.

A breathing apparatus with a closed circuit is called a rebreather.

A breathing apparatus with an open circuit is called a scuba tank.

The word “Aqualung” itself does not carry a semantic load, and appeared thanks to Jacques-Yves Cousteau and Emile Gagnan, who named the company (Aqualung, Aqua Lung) with this name, which began to mass produce this part of autonomous light diving equipment.

Over time, this name became familiar in common use throughout Europe and Asia. In our country, spearfishing Scuba diving is prohibited.

The scuba tank consists of two main parts cylinders – with a compressed breathing mixture and gearbox, lowering the high pressure in the cylinder to the values ​​required for inhalation.

The cylinder can be made of steel, aluminum alloys, titanium, carbon fiber, etc., as a result, the difference in weight, durability, and cost. The main requirement is to withstand high pressure. Conventionally, the equipment is divided into equipment with a possible pressure of up to 230 atm., and 300 atm.

When diving, the swimmer begins to experience water pressure, which increases as the depth increases. In order to take a breath, you need to overcome this force.

Muscle strength chest not enough to breathe, even at a meter depth. Therefore, the inhaled air must be supplied under pressure that compensates for the water pressure.

The greater the depth, the greater the supply air pressure should be. At the same time, breathing should remain as natural and comfortable as possible. This job is done by a diving regulator.

When diving to significant depths, and as a result, being under the influence of greater external pressure, causes complex physiological changes in the human body. The consequence of attempts to avoid the negative consequences of this impact was the use of various gas mixtures as a breathing mixture, which required design changes in the regulator.

The scope of this article is to consider only the general principles of operation.

The conversion of air pressure to the pressure required for inspiration occurs in two stages. The first, main stage of reduction is provided by the reducer - a part of the diving regulator installed directly on the cylinder valve.

The second stage of reducing pressure and automating the breathing process is performed by a “breathing machine” - a part located in the diver’s mouth and connected to the reducer by an air hose.

The gearbox or first stage can be of two types, piston and membrane.

Most regulators in use use a diaphragm circuit. To understand the principles of work, in my opinion, it will be enough to consider only it.

The easiest way to understand how this works is to watch this animation:

This shows the operating steps of a balanced first stage regulator.

When the pressure from the hose reaches a certain pressure, the reducer valve shuts off the air supply from the cylinder.

The system begins to be in equilibrium. The pressure in the hose, in this case, controls the opening and closing of the valve.

As soon as the diver takes a breath and the pressure drops, the valve opens and a new portion of air is supplied.

When the inhalation phase ends, the pressure in the hose increases and the first stage valve of the diving regulator closes.