Closure member for a connection system connecting system, closed-circuit breathing apparatus as well as method of producing a sealed fluid-communicating connection between two components of a closed-circuit breathing apparatus

Closure member for a connection system connecting system for the production of a sealed fluid-communicating connection between two components of a closed-circuit breathing apparatus circuit breathing apparatus as well as method of producing a sealed fluid-communicating connection between two components of a closed-circuit breathing apparatus. The present invention relates to a connection system (10) for producing a sealed fluid-communicating connection (50) between two components (61, 64) of a circuit breathing apparatus (60). Further, the invention relates to a closure element (20) for such a connection system (10), a closed-circuit breathing apparatus (60) having such a connection system (10) and a method of producing a sealed fluid-communicating connection (50) between two components (61, 64) of a such circuit breathing apparatus (60) and using such a connection system (10).