Relief device of space of nuclear power plant main production unit

A safety device is patented for the sealed space of a nuclear power plant reactor shaft, operating in the case of unpermissible internal overpressure. The aluminium membrane is inserted between two flanges. In the girder of the lower flange there is a threaded apperture into which is screwed the shank of a cutting blade which is secured with a nut. The advantage of the device is its accurate function within the range of bursting pressures, provided by the accurate pre-setting of the cutting blade. Moreover, the aluminium membrane is not adversely affected by a contaminated medium. (J.B.)