Patent ID: 8162186

Claim:
A refillable bottom dispensing package forming a closed space in which contents of fluid material can be stored and from which the contents can be dispensed, the package having a rigid wall adjacent a bottom thereof, the wall having a hole, a resilient valve regulating dispensing of the fluid material contained in the package through the hole, the valve being closed to passage of the contents through the hole when the contents of the package is substantially at atmospheric pressure and being opened by pressure on the contents when said pressure is above atmospheric pressure, the valve forming a flap seal that seals against a substantially radial surface of said wall, the flap seal extending radially from the hole a distance several times an average thickness of the flap seal to a perimeter, a sealing action of the flap seal against said wall surface by mutual contact existing across substantially a full radial width of the flap and being free of influence from structural elements of the package while being directly responsive in sealing force against the wall surface to a pressure level of the contents in the package space, an inter-relationship of the flap seal and the wall within the package being arranged to avoid impeding removal of the valve from the wall and the package.