Method and apparatus for stabilizing the pressure of a gas in a closed body

Apparatus for stabilizing a gas to a predetermined pressure in a closed body comprising:

• a hollow body;
• a first pipe connected to said hollow body and having a conductance C.sub.1, said first pipe being connected to a source of said gas;
• a second pipe connected to said hollow body and having a conductance C.sub.2, said second pipe being connected to a decompressing system, said first and second pipes and said hollow body directly and simultaneously interconnecting said decompressing system and said source during operation;
• and
• a third pipe connected to said hollow body and being adapted to be connected to said closed body and having a portion of least conductance C.sub.3, said conductance C.sub.1 being smaller than either of said conductance C.sub.2 and said least conductance C.sub.3, and said conductances C.sub.1 and C.sub.2 being so set that the gas pressure level inside said third pipe is substantially the same as said predetermined gas pressure attained in said closed body when the gas from said gas source constantly flows from said first pipe to said second pipe.