Abstract: Patent of invention for pressurizing and sealing device and process for hermetic systems, provided with a gas feeding conduit (1), comprising: a tubular body (10) defining an internal chamber (13) between a first end (11) which can be tightly seated against an open external end (2) of the gas feeding conduit (1) and a second open end (12), and a pressurized gas inlet nozzle (14) opened into the internal chamber (13); an elastomeric plug (30) which can be positioned inside the tubular body (10) in such a way that it can be selectively displaced from a pressurizing condition, sealing the second end (12) of the tubular body (10) when the internal chamber (13) and the hermetic system are pressurized through the pressurized gas inlet nozzle (14), to a plugging condition, in which it is sealingly fitted and maintained in the external end (2) of the gas feeding conduit (1) after said pressurization has ended; and an impelling means (40), which is coupled to the tubular body (10) and which can be selectively activate