IPA series oxygen rebreathers

 (from achieves of the Military and historical museum of artillery, engineering armies and communication armies in Russia)

Oxygen respiratory devices of the IPA series were developed in the 1930s.
The series consisted of three models differing mainly by the of oxygen addition mechanism.
The first sample of the device IPA-1 had no oxygen dosage oxygen mechanism. The oxygen addition was simply done by opening the valve of the rebreather. The second model of the device of the end of the 1930th years was- IPA2 It  already had an oxygen dosage  mechanism (a reducer from the bottle  continuous supplied oxygen in the lung). Further development of devices of the IPA series, and then ISA - went on the way of improvement of separate lungs, and as a whole the shape of breast oxygen devices didn't change until the second half of the 1950s. Before the emersion of the last breast device IDA-57, and the device IPA-3 was used in engineering armies of Armed forces up to the end of the 1940s/

 Easy diving device IPA-2

The device IPA-2 is developed in the mid-thirties and has the constructive signs which have remained in the subsequent models, namely: the reducer providing continuous supply of oxygen through a special dosage  device.
The device equipped with oxygen and an absorber, weighs 7,8 kg.
In water with the filled oxygen in the counterlung the device decreases in weight to 7 kg.
Also gains positive buoyancy, depending on bag filling - to 7 kg.
IPA-2 sizes: height - 370 mm, width - 370 mm, thickness - 120 mm.

Main parts:
a) respiratory bag;
b) the mechanism for continuous supply of oxygen;
c) oxygen cylinder with the dosage mechanism
d) canister;
e) valve;
f) breathing hoses with  mouthpiece, bandage and nasal clip (or the mask combining these details);
g) the case of the device on which all parts are mounted;
h) diving points.

In the package of IPA-2 are included: tool bag with keys and a set of spare details and a bag for carrying the device.

Thanks to Alexander Lebedev