Abstract: A protection apparatus for detecting and reducing overpressure in a fluid pipeline having a fluid input end (3) and a fluid output end (4), the fluid input end being connected in use to a fluid source, comprises: first (1) and second (2) pipeline valves connected in series along the pipeline with the first pipeline valve being connected at a location closer to the input end than the connection location of the second pipeline valve, the first and second pipeline valves being independently switchable between open positions in which fluid flow through the pipeline is permitted and closed positions in which fluid flow through the pipeline is blocked; a pressure transducer for determining the fluid pressure in the pipeline at a point intermediate the first and second pipeline valves; a bypass line having a first end connected to the pipeline between the input end and the first pipeline valve and a second end connected to the pipeline between the first and second pipeline valves; a bypass valve (9) connected along