Sealing device for a container for aseptically receiving a flowable product and container and method for aseptic filling

A closure device for a container for aseptically receiving a flowable product, comprising:

• a spout which has a product filling duct extending axially between a first end and a second end, wherein the first end forms a container-side end of the spout and the second end forms a closure-side end of the spout, and
• a closure cap which can be mounted onto the spout and which, in a mounted state, closes the second end of the product filling duct,
• wherein the closure cap is connectable in axially positively locking fashion to the spout in two axially different positions,
• wherein a first position of the two axially different positions is a position in which the closure cap is not fully mounted on the spout,
• wherein a second position of the two axially different positions is a position in which the closure cap is fully mounted on the spout, and wherein the closure cap bears sealingly against the spout in the first position and in the second position.