Diving regulator

The regulator, also lung machine or machine called short, enables you to breathe a pressurized breathing gas, even under water or in a toxic atmosphere. For this, the breathing gas from the compressed gas cylinder is reduced by the regulator on the pressure prevailing in the ambient pressure. Regulators are used in compressed air diving equipment, rescue organizations and in medical technology.

The regulator earlier consisted of a step. Today, two stages are common. The first stage reduces the cylinder pressure of usually 200 to 300 bar, to a mean pressure of about 4 to 12 bar ( depending on the manufacturer ) above the ambient pressure. The second stage reduces the mean pressure then to slightly above the ambient pressure.

History of development

The first regulator was developed between 1942 and 1943 by Émile Gagnan at the suggestion of the famous French marine explorer Jacques -Yves Cousteau and bore the name of " Aqualung ". It was based largely on previous technical concepts, such as Georges Comeinhes and Rouquayrol - Denayrouze.

The first dual-hose machines had only a pressure reducing stage, the reduced cylinder pressure directly to ambient pressure. Since this regulation leads to a high Ventilansteuerkraft, the divers had to go through inhalation and reach the thereby generated slight negative pressure, a two-stage principle was soon introduced. This two-step downward adjustment tank pressure to ambient pressure allows a much finer adjustments of the valve that is actuated by the Einatemunterdruck. The breath of comfort increases as a result. The intermediate pressure in the system is typically about 8 bar above ambient pressure. Based on the structural principle of the Einstufenautomaten also the first two-stage machines were arranged in a housing directly on the compressed air cylinder valve.

The air within this one body is then regulated down directly to ambient pressure initially to medium pressure and. This air at ambient pressure is then performed by the vending machine by two soft and non- pressure-resistant Gummifaltenbalgschläuche to a mouthpiece. The air guide in these two Faltenbalgschläuchen was controlled by one-way valves so that the inhaled air was supplied through the tubing, and the exhaled air was discharged to the regulator through the other tube to the back where she was blown off in the housing into the surrounding water and was free to escape through openings. Since this type of two uniform Convoluted led to the vending machine from the mouthpiece, was this guy called " dual-hose machine ". This voluminous two Convoluted have long determined the typical picture of a diver.

This principle of two hoses had the advantage that the mouthpiece was very easy, and ascended no troublesome bubbles off the mask of the diver. Especially for underwater photographers and videographers, this was popular. The downside was mainly that the second stage could only regulate down to the ambient pressure at which the machine was located straight, and not to the ambient pressure of the mouthpiece. The result was that the mouthpiece decency significantly higher air pressure when the regulator was something deeper, and conversely, a significantly noticeable under low pressure when the regulator was higher. When diving, which had the effect that the diver during ascent almost the lung was inflated while you had to suck descent, less the ( upside down ).

This design principle has not enforced for that reason. The second stage has been integrated into the mouthpiece so that the breathing air is supplied to the pressure prevailing in the immediate vicinity of the mouth. Since in this point only one hose, the medium-pressure hose leading to the mouthpiece, this type is called Einschlauchautomat. Einschlauchautomaten offer also has a push button on the front of the device allows you to control the valve between fluid pressure and ambient pressure manually and thus to operate the so-called air shower. One can then blow out the mouthpiece or inflate a lift bag.


The dominant structural principle consists of the following elements:

The first stage is directly by means of a DIN (DIN EN 144-2/3 and ISO 12209-2 ) or INT connection ( ISO 12209-3 ) screwed to the valve of the bottle. She has at least one connection for the second stage, but usually more connections still exist, eg, for a so-called octopus ( an additional second stage ) and for a buoyancy compensator. In addition, even at least one high pressure port ( HD) for the pressure gauge available in order to determine the residual pressure and thus the remaining breathing gas supply in the bottle can. The first stage consists of chromed brass, stainless steel or titanium.

The second stage, which is connected via a pressure hose (MD) with the first, is also either made ​​of metal ( brass, stainless steel ), plastic or a combination of both materials. It's the part of the machine, which is located directly in front of the mouth and supplies the wearer with breathing through a mouthpiece gas.

The applied pressure in the medium pressure hose will be completed in the second stage via a spring- loaded valve first. The spring force is adjusted so that even the valve remains closed. A small rocker arm on the valve can open this gently pressing. This rocker is operated by a diaphragm which compares the pressure with the ambient pressure in the mouthpiece. Breathes of a carrier, it produces a negative pressure relative to the surroundings in the mouthpiece. This membrane is moved from its rest position, via the rocker arm opens the second stage valve, and respiratory gas flows into the mouthpiece - the user can inhale. This membrane control ensures that the provided pressure of the breathing gas always adapts to the pressure of the environment, and thus allows easy breathing. For divers the chest would otherwise anarbeiten inhalation compared with the rising of the depth in water pressure, which would make impossible the inhalation in a few meters below the waves.

Exhalation is made possible by a further valve at the second stage. This usually consists of a thin rubber or silicone membrane, which is in its rest position before the blowout and it seals. Damage to this membrane can lead by inhalation for the inflow of the surrounding medium into the oral cavity and the lungs, which can be annoying to life-threatening depending on the amount and medium ( inhalation of water, inhalation of toxic gases).

Two more important for divers functions can also be integrated into the second stage: the exhaust tee and the air shower. The exhaust tee is an enlarged and laid to the side outlet of the exhalation valve. This means that the exhaled air escapes laterally downstream of the diving mask and does not pass through the field of view. The air shower consists of a button on the side, over which one can push the inhalation diaphragm manually. In this way, air flows through the second stage and the mouthpiece. If the mouthpiece is held in the mouth, the excess air escapes through the exhalation valve and tears while slightly in the second stage water located with it. The air shower also is used to inflate lift bags and buoys under water with air.

When regulators modern diving equipment at least the following four components are connected to the first stage:

Regulators are built fail-safe. If they fail, they do not interrupt the air supply. Let flow out continuously in this case the air.


The regulator for compressed air breathing apparatus, as used among others in the fire service, Although different in appearance from the divers, but performs the same function. Here, the regulator is not in the mouth but bolted directly to the respirator. For the fire department divers as full face masks compression are used. The exhalation valve is integrated here in the regulator. There are run as normal printing technology and as a printing technique. In normal printing technology of the air pressure in the mask corresponds to about the ambient pressure; at the overpressure technique, he is slightly above the ambient pressure to prevent at a ( however temporary ) leak in the mask intrusion of toxic gases. The disadvantage is, for one thing, that this air escapes into the environment. On the other hand increases the exhalation pressure necessary because the exhalation valve, which maintains the pressure, must be overcome. There are types of devices in which the warning device is integrated in the regulator.

Medical regulators are applied in medical technology, when it comes to ventilation with certain respiratory gases or performance diagnosis.