Patent ID: 8002130

Claim:
A closure system for a vial of the type having an upwardly-facing mouth opening bounded by a rim, the closure system comprising: an elastic closure part shaped to sealingly engage with the mouth opening, having a lower surface facing the interior of the vial and an opposite upper surface facing away from the vial, and capable of being punctured by a needle, wherein the closure part has a downwardly extending plug part which fits into the mouth opening of the vial, and an outwardly extending peripheral flange part, a downward facing surface of which can engage with the upward facing surface of a rim of the vial mouth opening, and upwardly of the flange part of the closure part is upwardly convex; a clamp part able to engage with the vial, and able to bear upon the closure part to hold the closure part in a closing relationship with the mouth opening, the clamp part defining an upper aperture through which a region of the upper surface of the closure part is exposed when the clamp part is engaged with the vial, a cover part, engageable with the clamp part and/or the vial after the clamp part has engaged the vial and borne upon the closure part to cover the said region of the closure part when so engaged, wherein the cover part engages with the upper surface of the closure part to provide two or more concentric ring-shaped seals which isolate a region of the upper surface of the closure within the innermost ring shaped seal from the environment, at least part of the cover being removable from the vial to allow access to the closure.