Pressure reducing system for a breathing apparatus

A breathing system comprising:

• a tank of a breathable gas;
• a first pressure reduction stage situated downstream of the tank;
• a second pressure reduction stage situated downstream of the first stage and comprising a pressure reducing system;
• and
• a tube connecting the first stage to the second stage and in which the breathable gas moves,
• wherein the pressure reducing system includes:
• a conduit for supplying the breathable gas under pressure;
• a mouthpiece for inspiration of the breathable gas by a user;
• a valve poppet operatively interposed between the conduit and the mouthpiece,
• the valve poppet being movable between:
• a closed position, in which the valve poppet prevents passing of the breathable gas from the conduit to the mouthpiece, and
• at least one open position in which the valve poppet permits the passing of the breathable gas from the conduit to the mouthpiece,
• said conduit comprising an abutment against which the valve poppet abuts in the closed position and from which the valve poppet is distanced in said at least one open position, and
• said abutment defining an annular interface which in the closed position is in contact with the valve poppet in order to perform a fluid-dynamic sealing action that prevents the passing of the breathable gas from the conduit to the mouthpiece,
• the annular interface being located on an end surface of the abutment;
• and
• a balancing chamber that defines a balancing zone, the balancing chamber during operation enabling at least a partial balancing of the force exerted by the pressure of the breathable gas on the valve poppet at the abutment, said valve poppet being at least in part interposed between the abutment and the balancing chamber;
• the valve poppet defining a passage that places the conduit and the pressure balancing chamber in fluid communication even in the closed position of the valve poppet, wherein a section of said passage, in at least one of said open positions extends in the conduit beyond said annular interface;
• and wherein said passage extends in the conduit beyond said annular interface in all of said open positions of the valve poppet.

A method of pressurization, the method comprising:

• providing a pressure reducing system that includes:
• a conduit for supplying a breathable gas under pressure;
• a mouthpiece for inspiration of the breathable gas by a user;
• a valve poppet operatively interposed between the conduit and the mouthpiece,
• the valve poppet being movable between:
• a closed position, in which the valve poppet prevents passing of the breathable gas from the conduit to the mouthpiece, and
• at least one open position in which the valve poppet permits the passing of the breathable gas from the conduit to the mouthpiece,
• said conduit comprising an abutment against which the valve poppet abuts in the closed position and from which the valve poppet is distanced in said at least one open position, and
• said abutment defining an annular interface which in the closed position is in contact with the valve poppet in order to perform a fluid-dynamic sealing action that prevents the passing of the breathable gas from the conduit to the mouthpiece;
• and
• a balancing chamber that defines a pressure balancing zone, said valve poppet being at least in part interposed between the abutment and the balancing chamber;
• the valve poppet defining a passage that places the conduit and the balancing chamber in fluid communication, wherein a section of said passage, in at least one of said open positions extends in the conduit beyond said annular interface;
• when the valve poppet is distanced from the abutment and the pressure reducing system is depressurized, the method comprising the steps of:
• supplying the breathable gas under pressure along the conduit;
• and
• intercepting at least a part of the breathable gas coming from the conduit through said passage which extends beyond said annular interface and conveying the part of the breathable gas to the balancing chamber in order to bring said valve poppet into contact with said abutment and close off the passing of the breathable gas from the conduit to the mouthpiece.