Patent ID: 7717129

Claim:
A flow control system, comprising: a source for the flow of a first fluid; a source for the flow of a second fluid; means for switching between said flow of said first fluid and said flow of said second fluid; a first line for said flow of said first fluid; a second line for said flow of said second fluid; and a fitting comprising: a first entry portal for said first line; a second entry portal for said second line; an exit portal for either said first fluid or said second fluid; a normally closed duck bill valve, said duck bill valve having first and second bill portions capable of being opened when said means for switching between said flow of said first fluid and said flow of said second fluid switches said flow of said first fluid to said flow of said second fluid; and a receptacle having an internal surface closely mating with an external surface of said duck bill valve so as to minimize a gap volume between said receptacle and said external surface, dispose a tip of said first and second bill portions proximate said first flow of fluid, and dispose said first and second bill portions parallel to said flow of said first fluid.