A cap for cell culture container enclosing a culture volume and having an opening, comprising a valve arrangement, suitable for filling of the cell culture container with a fluid and/or for pumping fluid out from the cell culture container, and a compensation opening suitable for aerating the cell culture container and/or for pressure compensation during filling and pumping out, said valve arrangement being designed to be switchable between an outlet position and a blocking position, to be connectable to a fluid supply interface, and to be switchable without contact.