Important Information You Must Read This

IDA-71U

Russian Rebreather

Manual

Disclaimer Notice

Important information you must read this !!

This manual is a translation from the German Manual, that was itself a translation from the original Russian. As such certain inaccuracies may have been propagated within the text of the manual. Therefore all uses of this manual are strictly limited to theoretical discussion & non-diving demonstration of the IDA-71 apparatus.

It should in no way whatsoever be interpreted as a complete or concise document for the purposes of planning or carrying out any diving activities.

This Document may be freely distributed, provided no alterations or modifications are made to it, and that the translator details below are maintained. Please see separate diags for references in the text.

It is also forbidden for anyone to remove, clip or delete this disclaimer from the beginning or end of this document.

Translated by Chris Walker, July 1998.

Contact
Published on with permission of Chris Walker.
I would also express my gratitude for the generous
offer from Chris offering this manual for free!

Special Note from the Translator

I originally translated this manual in 1998. It was the full East German version of the Russian manual that covered all the operational modes of the IDA71U these being Diving, Parachuting & High Altitude unpressurised Aircraft use. As I was only interested in the diving use of the unit, I did not translate the pages & sections that related to the other modes of operation. So apologies to anyone expecting them.

I had never attempted a project like this before & as the original manual was over 90 pages including the diagram pages, it was a major task. It took 3 months of almost continuos work in my spare time. I used an early version of character recognition software that I was investigating at work. This involved scanning a paper version of the whole manual, then proof reading it in German to ensure all the special characters were correctly represented, before using an early version of Systrans to do the base translation from German to English. This explains the somewhat “pigeon” English portions of the document. I also had to substitute certain words from their literal translation, to something divers might understand.

The original intention for all of this was to provide me with the details of how the unit functioned, as I taught myself how to dive & modify this closed circuit rebreather.

I have now given up diving as a major past time & have taken this opportunity to pass this manual into the public domain for posterity. I hope it of use to some of you.

Regards

Chris Walker

June 2005.

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TECHNICAL DESCRIPTION

1. Introduction

The technical description and operating instructions for the breathing equipment contain a summary of the technical characteristics, and a representation of the equipment as well as the fundamental function modes.

2. Intended Purposes.

2.1 The Equipment for the artificial respiration;-

• of divers for dives up to 40m depth,
• of flight crew in unpressurised aircraft up to an altitude of 8000m,
• of parachutists who leave aircraft by from up to 8000m.

3. Technical Parameters

3.1The apparatus is functional with pressures in the Oxygen and Nitrox Cylinders from 30 to 200Bar.

3.2The magnetic field amounts to no more than 10 (gamm) for the individual elements of the equipment specified below, with a distance of 100mm from the Measuring instrument:

• Apparatus IDA-71P Housing
• Nitrox Cylinder
• Scrubber cartridge
• Purging System & pipes
• Weight Belts .

3.3Under water use with a breathing rate of 30L/min, and an ambient temperature of 14-18C results in less than 4hours dive capability.

Of this 3.5hours remain with a depth limit of 15m, or 0.5hr with a depth limit of up to 40m.

Dives in constant depth produce no Output of the gas from the breath bag.

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Apparatus IDA-71P

3.4High pressure components (Cylinders, Regulators) have a working pressure of 200Bar.

3.5Low pressure components (breathing bag, scrubber cartridges, mouth piece) are safe up to 1.5 Bar.

3.6The resistance of the Equipment with uncharged cartridges with a flow of 100L/min, is approximately 55MilliBars.

3.7The pressure at the Regulator exit of the Oxygen Cylinder is 4.2 to 4.6 Bar with a breathing rate of 40L/min and a Cylinder pressure of 130-150 Bar.

3.8The pressure at the Regulator exit of the Oxygen Cylinder (without breathing) is over 6Bar with a Cylinder pressure of 180-200Bar.

3.9The pressure required to open the relief Valve of the Regulator of the Oxygen Cylinder is to 10 to 15 Bar.

3.10The resistance of the lung apparatus with a flow rate of 1 to 30L/min is 110 to 160MilliBars.

3.11The Valve of the lung apparatus is closed with a gas pressure on the Valve from 2 to 9 Bar.

3.12The resistance of the relief Valve of the breath bag with a flow of 1 to 100L/min is 120 to 220MilliBars.

3.13The Valves for breathing in and out of the Mouth piece are closed with a pressure on the Valve of 200MilliBars. A reverse flow is permitted of not more than 0.5L/min.

3.14The Valves of the Coupling are closed with a pressure

a) on the High pressure elements from 2 to 9Bar

b) on the low pressure elements of 100 MilliBar to 2Bar

c) on the Valve of the Oxygen line to 6 Bar.

3.15The Valve of the Oxygen Cylinder is closed with a complete tightening of the Valve (pos " Closed ") with a Cylinder pressure to 200Bar.

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3.16The relief Valve of the Oxygen Cylinder is closed with a Cylinder pressure to 200 Bar; the torque should not exceed 30kg/cm2.

3.17Turning the Valve of the Oxygen Cylinder from the position "OPEN” 1/4 to 2 revolutions. into the position " CLOSED ",

3.18The Valve of the Oxygen Cylinder requires less than 1.5kg/cm2 of torque to fully close it.

3.19The Oxygen volume, which the purging system uses, is in the order of 20 to 27L; the purging procedure lasts 10 to 25 seconds.

3.20The effort required to connect the purging system to the apparatus is 15kg and for separation from the apparatus do not exceed 10kg.

3.21The positive Buoyancy of the apparatus amounts to approx-0.5 kg under the following conditions;

a) the apparatus is completely filled with chemicals and Oxygen.

b) the breathing bag is filled to a pressure, at which the relief Valve opens.

3.22The dimensions of the apparatus. (fig. 4)

3.23The weight of the apparatus with uncharged scrubber cartridges without connections amounts to:

• 15.7 kg without purging system
• 16.2 kg with purging system

3.24The weight of the chemicals in the cartridges amount to;-

• a) Substances 0-3 = 1.8 kg
• b) absorber HP-I = 1.8 kg
• c) substances WPW-1 =1.1 kg

3.25The volume of the Oxygen Cylinder amounts to 1L.

Nitrox Cylinder

3.26The pressure at the Regulator exit amounts to 7.2 to 7.6 Bar , with a consumption of 40L/min and a Cylinder pressure of 130-150 Bar.

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3.27The pressure at the Regulator exit (without consumption) with a Cylinder pressure of 180-200 Bar is over 9 Bar.

3.28The relief Valve of the Regulator opens with a pressure from 10 to 15 Bar.

3.29The Oxygen volume, that after Opening of the Valve of the Oxygen Cylinder the purging system uses, amounts to 20 to 27L; the purging procedure takes 10-25 seconds.

3.30The volume of the Nitrox mixture, that with Depth the purging system usesis from 35 to 50L; the purging procedure takes 15-35 seconds.

3.31The depth, in itself at a temperature of + 20C (± 5C).

a) the Supply of the Nitrox mixture when descending connects at 15 to 18m,

b) the Supply of the of Oxygen when ascending connects, at 12 to 15m.

3.32The high and low pressure elements seal, if the Nitrox Cylinder is attached to the apparatus, the Valves of the Oxygen and Nitrox Cylinders are open and the gas pressure in the Cylinders is up to 200 Bar.

3.33The Valve of the Cylinder is closed with a complete tightening of the Valve (pos “CLOSED ") and a Cylinder pressure from 30 to 200Bar.

3.34To the Connect the Nitrox Cylinder to the apparatus with the Valve of the Oxygen Cylinder open, a force of no more than 15 kg is required.

3.35The power required for the separation of the Nitrox Cylinder from the apparatus is less than 10 kg; the following conditions apply:

a) the angle between the strained cord of the Coupling and the long axle of the Equipment can be up to 35C,

b) with the Valve of the Oxygen Cylinder opened.

3.36The filling Valve is closely with a Cylinder pressure up to 200 Bar, the torque may not exceed 30 kg/cm.

3.37Turn the Valve from the position " OPEN " 1/4 to 2 revolutions to bring it into the position " CLOSED ".

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3.38The Valve force required should be no more than 1.5kg/cm2.

3.39The weight of the Nitrox Cylinder is less than 6 kg.

3.40Fig. 19 shows the dimensions of the Nitrox Cylinder.

3.41The volume of the Nitrox Cylinder amounts to 1L.

Breathing Hose

3.42The Breathing Hose is attached to the Mouth piece with a pressure acceptance in the hose up to 100mm MilliBars.

An air supply is not permitted over 0.2L/min.

3.43The resistance at the exhalation Valve of the hose amounts to 30-40 MilliBars with a flow of 15L/min.

3.44Fig. 22 shows a representation of the Breathing Hose.

3.45The weight of the hose is not more than 0.3kg.

Starter

*** SECTIONS 3.46 - 3.53 HAVE BEEN REMOVED - CW ***

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4. Components of the Equipment

Notes:

4.1The equipment comes supplied with empty cartridges and a pressure in the Oxygen and Nitrox Cylinder from 30 to 150 Bar.

5. Mechanism and Function modes of the Equipment

5.1Functional modes of the Equipment

5.1.1Functional modes of the Equipment with dives up to 15m depth (fig. 1).

The apparatus protects the breathing organs from the influences of the environment and works in the closed breathing cycle, whereby the exhaled gas mixture is replenished. For functionality the apparatus needs the elements specified below:

• Breath Bag (pos 2)

serves as a container for the exhaled gas mixture.

• Demand Valve (pos 10)

serves for the automatic Oxygenation on demand, into the breath bag .

• Relief Valve (pos 1) vents surplus gas mixture from the breath bag (pos 2) through the pipe (pos 3) into the environment.
• Mouth piece (pos 6) serves for the regular circulation of the gas mixture when breathing in and out.
• Cylinder (pos 17)

is a container for keeping the compressed Oxygen.

• Regulators (pos 15) lowers the pressure of the Oxygen, into the Demand Valve (pos . 10) and the Coupling (pos 20).
• Scrubber Cartridge (pos 13 & 14)

where the exhaled mixture has CO2 removed, before reuse.

Opening of the Valve (pos 18) allows the Oxygen from the Cylinder into the Regulator (pos 15), & the pressure is reduced; the Oxygen also flows into the gauge (pos 16), which indicates the pressure in the Oxygen Cylinder (pos 17). After passing through the Regulator (pos 15), the reduced pressure of the Oxygen flows through the Valve (pos 19) & into the range " A " of the separator

element and the piping (pos 12) to the Demand Valve (pos 10).

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Protecting the diving functions, the respiration is as follows;

The exhaled gas mixture continues to pass the exhalation Valve (pos 5) of the Mouth piece (pos 6), & arrives in the Breathing Hose for the exhaled gases (pos 4) and flows into the cartridges (pos 13 and 14).

After the gas mixture in the cartridges is cleaned of Carbon dioxide by the chemicals in the scrubber cartridges, the gas mixture flows into the breath bag (pos 2).

The gas mixture for inhalation flows through the inhalation hose (pos 9) and the inhalation Valve (pos 7) to the Mouth piece (pos 6).

With increasing Depth or if their is insufficient gas in the breath bag, the Demand Valve (pos 10) operates as follows:

With reduced pressure in the breath bag the diaphragm (pos 8) of the

Demand Valve (pos 10) is deflected by external pressure & presses on the

lever system Valve (pos 11), and supplies the breath bag (pos 2) with the Oxygen, which is needed for inhalation.

With Positive pressure in the breath bag (pos 2) the surplus gas is

discharged by the relief Valve (pos 1) by means of the pipe (pos 3) into the environment.

5.1.2Function mode of the Equipment with dives up to 40 m depth (Fig. 2)

Diving up to 40 m depth can only be made, by the equipment with the inhalation of a Nitrox Gas. With dives into a depth of over 15m the equipment’s Coupling (pos 20) is therefore connected to a Nitrox Cylinder, whose Valve (pos 1) is opened.

Opening the Valve (pos 35) of the Oxygen Cylinder, causes the loop to be purged with Oxygen as follows:

The Oxygen flows from the Oxygen Cylinder into the Regulator (pos 32), where the pressure is reduced. Then the reduced Oxygen pressure passes through the Valve (pos 31) and distributes itself within the range " A " of the Coupling (pos 21). From here the Oxygen flows into the Piping (pos 29) into the Demand Valve (pos 28). It then flows through the opened Valves (pos 34 and 36) of the Coupling (pos 20 and 21) & flows through the hose (pos 18) into the chamber of the Valve (pos 40), which is closed by the spring (pos 39) on to the Valve seat.

The Oxygen flows into the Valve chamber (pos 37), where it distributes itself to the Nozzle (pos 17) and into the diaphragm range " B ". Under the pressure of the Oxygen the diaphragm (pos 14) of the Valve seat yields & allows the Oxygen

to reach the entrance to the Nozzle (pos 13).

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After passing the Nozzle (pos 13) the Oxygen arrives at the Valve (pos 46) and the pressure opens it, & allows the Oxygen to flow through the hose (pos 15) into the Valve chamber (pos 19), furthermore it continues through the opened Valves

(pos 19 and 22) & the Coupling (pos 20 and 21) & into the piping (pos 23) then into the breathing system for its purging.

The existing gas mixture in the breath bag (pos 25) is forced out through the relief Valve (pos 24) and the pipe (pos 26) into the environment.

At the same time the Oxygen continues to flow through the Nozzle (pos 17)

into the range " B " until the Oxygen pressure equalises itself on both sides of the Nozzle (pos , 17) and diaphragm (pos , 14). Afterwards the diaphragm (pos 14) under the pressure of the spring re-seats itself on the Valve seat and stops the Oxygen flow to the breath bag.

The Oxygen volume for the purging of the breath system is dependant on the diameter the Nozzle (pos 17), with which the duration the purging is regulated, as well as of the diameter of the Nozzle (pos 13), which ensures the purging for the necessary quantity of the Oxygen, which is steered by the Nozzle (pos 17).

After Opening of the Valves (pos 1) of the Nitrox Cylinder the gas mixture flows into the range of the gauge (pos 3), which indicates the pressure of the gas mixture in the Cylinder and in the Regulator (pos 2). The pressure of the gas mixture is reduced by the Regulator to a certain value, which importantly is more than the pressure at the exit of the Oxygen Regulator. The gas flows through the hose (pos 4) into the Valve chamber (pos 9).

Between sea level and a depth up to 15m the Valve (pos 9) is closed and it does not flow gas into the automatic loop purge. In a depth of 15 - 18m the Depth sensor (pos 45) is compressed the by the water pressure and moves the lever (pos 5), by the strength of the spring (pos 6).

The push rod (pos 7), under the influence of the spring (pos 43) closes the Valve (pos 44). Then the lever (pos 5) opens the Valve (pos 9) via the push rod (pos 10). After opening the Valve (pos 9) the gas mixture distributes itself evenly & is channelled to the Nozzle (pos 11), & into range " G “ and " D”, where the force on the diaphragm (pos 42) is greater than the resistance of the spring (pos 41).

Whereupon the gas pressure forces the push rod (pos 38) to move the Valve (pos 37) against the Valve seat on the other side. The Valve prevents the Oxygen reaching the Oxygen purging mechanism and disconnects the chamber of the Valve (pos 37) from the Valve (pos 46). The surplus Oxygen, which is in the container " B ", flows through the Nozzle (pos 17) and the Valve (pos 46) into the breath bag & discharges the pressure in the container " W " to the breath bag (pos 25) and thus equalises the pressure in the system.

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Then the Nitrox gas mixture flows through the Valve (pos 40), & the pipe (pos 18) and the opened Valves (pos 36 and 34), via the piping (pos 29) into the Valve chamber (pos 28) of the Demand Valve (pos 27) and by the piping (pos 30) into the chamber of the Valve (pos 31), where it seats the Valve (pos 31). This happens, because the pressure of the Nitrox mixture is importantly higher than the pressure of the Oxygen, thereby the Oxygen is prevented from reaching the breath bag and the Demand Valve.

The pressure of the gas mixture, which is at the Nozzle (pos 11) and in the diaphragm range, follows the same procedure as during the Oxygen purging exercise, i.e. the gas flow through the Nozzle (pos 11) causes an equalisation of pressure in the range " E " and in the diaphragm range " G ". The diaphragm lifts from the Valve seat and ensures the flow of the gas mixture over the Nozzle (pos 12) up to the equalisation of the pressure within the ranges " G " and " E ". Therefore the purging of the breath system with the Nitrox mixture begins with the opening of the Valve (pos 9). With the inflow of the gas mixture to the Demand Valve (pos 27) the Oxygen supply is terminated to the purging device and Demand Valve . The volume of Nitrox Gas for the purging of the breath bag is just as dependant on the diameter of the Nozzles (pos 11 and 12).

The reverse of this procedure takes place during surfacing from depths of over 18M, when the loop is purged again with Oxygen.

This procedure is described as follows:

With the reduction in water pressure, the Depth Sensor (pos 45) expands & overcomes the resistance of the spring (pos 6) and removes the lever (pos. 5) from the push rod (pos 10).