The present invention relates to the sealing of connections between pressure parts such as pipes, conduits and components of pressure vessels and the like.
U.S. Pat. No. 4,795,171 issued Jan. 3, 1989 for a Self-Pressurized Shaft or Closure Seal, describes a variety of arrangements for sealing the penetration of a shaft or stem in a pump or valve, and closing an opening in a pressure vessel, by advantageously utilizing the difference in pressure between the system within the pump, valve or vessel, and the ambient air pressure. The advantages resulting from use of a self-pressurized closure are fully set forth in the '171 patent, the disclosure of which is incorporated herein by reference.