Freeflow means that gas streams out uncontrollably from the compressed gas cylinders. When diving, this means the freeflow of the regulator: Hereby the air escapes uncontrollably. This process can become dangerous. For this reason, it is important to know what you can do about it in case of emergency.
How can freeflow happen?
The two most common causes for gas to stream out of the diving device uncontrollably are the icing of the diving regulator and a wrong installation of the scuba (e.g. of the bubble deflector). An icing can arise when there is still some moisture in the gas mixture. Due to the high pressure of the gas mixture, this one can freeze. Thereby the pressure inside falls and the gas escapes uncontrollably.
How do I react correctly to freeflowing?
Depending on the system used, first you can continue breathing normally or you are immediately dependent on buddy breathing with your buddy. Even when you still receive air through the breathing device, the air is very cold though and it becomes empty significantly more rapidly. That is why it is particularly important to keep calm and not to panic!
With so-called downstream-systems, you should keep the valve closed until the ice inside is melted. Afterwards you can breathe normally again. With an upstream-system, only a specialist can change the iced valve.
Generally in case of freeflowing, it is important to end the dive as quickly as possible, because due to the high loss of air pressure, it is difficult to estimate the air supply.
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