主权项 |
1. An apparatus for use in a pipeline network to protect a line to be connected from contamination, said apparatus comprising a pressure relief device, said pressure relief device comprising: a first safety valve, a second safety valve, a connecting pipeline, a supply line, a supply-line safety valve, and a discharge line, wherein said first safety valve comprises an inlet side and an outlet side, wherein said first safety valve is connected to said line to be protected from contamination by said inlet side and to said connecting pipeline by said outlet side, wherein said first safety valve is configured to open in response to a first excess pressure in said line to be protected from contamination, and wherein said second safety valve comprises an inlet side connected to said connecting pipeline and an outlet side for discharge of working fluid from said connecting pipeline into an outflow, wherein said second safety valve is configured to open and discharge said working fluid in response to a second excess pressure in said connecting pipeline, wherein said connecting pipeline has a length, wherein said connecting pipeline extends between said first safety valve and said second safety valve, wherein said connecting pipeline connects said inlet side of said second safety valve to said outlet side of said first safety valve, and wherein said connecting pipeline separates said inlet side and said outlet side by a space extending between said first and second valves, wherein said space extends between said first and second valves having at least said length, wherein said supply line carries said working fluid to said connecting pipeline, wherein said supply-line safety valve is disposed along said supply line, wherein said discharge line connects to said connecting pipeline for removing said working fluid carried to said connecting pipeline by said supply line, and wherein said working fluid comprises a liquid or gaseous flushing, cleaning and/or sterilizing agent that, in operation, forms an active sterile block in said space of said connecting pipeline between said first and second safety valves, whereby risk of contamination of said line to be protected when said first safety valve is open and said second safety valve is closed is reduced. |