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The actions taken when safing goes active depends on the mode. In disabled mode, no action is taken because all the engine is already "safed" as all valves must be closed prior to entering disabled and must remain so. In cold mode, all valves are immediately closed as fast as possible. Safing in cold mode prioritizes the safety of people in proximity to the engine, albeit potentially damaging the system. In hot mode, there is no personnel allowed within the safe blast radius of the engine and fuel is assumed to be live in the system, for this reason the purge is run after closing fuel and oxidizer valves. This prioritizes making the engine safe to approach without damage to the system, but does leave introduce pressure in the line from purge purging so is not optimal if there are personnel nearby.
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