Method of filling, sampling and sealing an aseptic tank

A method of aseptically sealing and sampling an aseptic storage tank containing sterile product comprising the steps of:

• connecting first and second aseptic valves in series with an opening in the tank,
• closing the first valve to seal the valve-closure cavity of the first valve from the tank opening to which a first port of the first valve communicates when the first valve is open,
• introducing liquid chemical sterilant into the valve-closure cavities of the first and second valves to sterilize and establish first and second aseptic barriers between the tank opening and the environment,
• closing the second valve to seal the second valve-closure cavity from the first valve-closure cavity,
• unsealing a port in said second valve,
• connecting a third valve to said unsealed port of said second valve to establish alternate flow paths including a) a first flow path between said unsealed port of said second valve and said environment and b) a second flow path between said unsealed port of said second valve and a sample container,
• introducing liquid chemical sterilant into said second valve-closure cavity via said first flow path to sterilize said unsealed port of said second valve and said second valve-closure cavity,
• operating said third valve to establish said second flow path, and
• opening said first and second valves to permit sterile product from said tank to enter said sample container via said first and second valve-closure cavities and said second flow path.