A pressure relief device for pipeline networks includes first and second safety valves, each having an inlet side and an outlet side. The first safety valve is connected to a line of the pipeline network by its outlet side. A connecting pipeline extends between the two safety valves and connects the inlet side of the second valve to the outlet side of the first. A supply line carries a working fluid to the connecting pipeline, a supply-line safety valve for the supply line, and a discharge line connected to the connecting pipeline for removing working fluid carried to the connecting pipeline by the supply line.