Patent ID: 8430261

Claim:
A closure cover for tanks under internal pressure, comprising a cover body ( 6 ) which can be fixed in a tank neck by means of rotation, a cover ( 14 ) provided with a handle ( 15 ) operatively connected to the cover body ( 6 ), and a pressure control valve, wherein: a) a driver ring ( 22 ) acted upon by a compression spring ( 23 ) being arranged between the cover body ( 6 ) and the cover ( 14 ), one side of the driver ring being connected in a torsionally rigid manner to the cover ( 14 ) and the other side being connectable in a torsionally rigid manner to the cover body ( 6 ) as a function of the pressure prevailing within the tank, b) the pressure prevailing within the tank acting on the driver ring ( 22 ) via a diaphragm ( 20 ) and moving said driver ring against a force of the compression spring ( 23 ) if the pressure exceeds a certain first threshold value, thus releasing the torsionally rigid connection, and c) a pressure control valve ( 40 ) concentric with the cover body ( 6 ) and having a further compression spring ( 41 ) being fitted, said pressure control valve opening if the pressure within the tank exceeds a second, higher, threshold value, wherein d) the diaphragm ( 20 ), which is fixed by means of its outer rim ( 20 . 1 ) on the cover body ( 6 ), has a form of an annulus which is supported on its side facing away from the driver ring ( 22 ) by an annular disk ( 31 ) and is fixed in a sealing manner on the cover body ( 6 ) by means of its outer rim ( 20 . 1 ), e) arranged radially within the annular diaphragm ( 20 ) is a valve body ( 40 ) of a pressure control valve, an upper rim of which, which forms a flange ( 40 . 1 ), reaches around the diaphragm ( 20 ) from inside, with a result that the operative surface ( 20 . 3 ) of said diaphragm is at least partially clamped between the flange ( 40 . 1 ) and the annular disk ( 31 ) when the valve is closed wherein, from the flange ( 40 . 1 ) downward, the valve body ( 40 ) forms a cylinder ( 40 . 2 ) which is closed at the top and which is accommodated by a cylindrical space ( 43 ) formed within the cover body ( 6 ), f) for which purpose a further compression spring ( 41 ) is provided between the annular disk ( 31 ) and a spring plate ( 42 ) arranged at the lower end of the valve body ( 40 ).