Carbonated beverage package

A carbonated beverage package comprising

• a container having an opening with a peripheral lip defining a free edge,
• said container having a downwardly and outwardly inclined sealing surface spaced from the free edge of said peripheral lip,
• a closure of plastic material such that it will flex in thin cross section,
• said closure having an annular wall, a radial wall engaging the free edge of the peripheral lip of the container and a transverse wall defining a convex surface facing inwardly of the container,
• interengaging means between said radial wall and said container,
• said closure having a downwardly and outwardly inclined integral annular sealing surface at the juncture of the axial wall and transverse wall,
• said sealing surface of said closure engaging said sealing surface of said container and placing said axial wall under tension,
• said closure having a pressure relief rib at the juncture of the radial wall and axial walls such that axial force in the area overlying said rib will move a portion of said annular sealing surface of said closure away from the sealing surface of said container,
• said closure having a pressure relief opening through which the pressure in the container can be relieved to the atmosphere such that the closure can thereafter be readily removed from the container.