SHUT-OFF DEVICE AND PROCESS FOR PRODUCING A SHUT-OFF DEVICE
The invention relates to a shut-off device ( 1 ) and a process for producing a shut-off device with a housing ( 2 ) and a shut-off flap ( 3 ) that is pivotally located in the housing, a shut-off flap seat ( 7 ) formed by the components ( 2; 3; 8, 12 a; 12 b ) being located between the housing ( 2 ) and the shut-off flap ( 3 ). To achieve the object of ensuring a good fit and thus a high level of tightness of the shut-off device, it is suggested according to the invention that the components ( 2; 3; 8, 12 a; 12 b ) of the shut-off device ( 1 ) that form the shut-off flap seat ( 7 ) are subjected to treatment by cold ageing in the low temperature range. This treatment by cold ageing takes place advantageously before final mechanical working of the components ( 2; 3; 8, 12 a; 12 b ) with liquid nitrogen.
1 . In a shut-off device, especially a shut-off device for operating temperatures below 0° C., comprising a housing ( 2 ) and a shut-off flap ( 3 ) pivotally located in the housing, and between the housing and the shut-off flap there being a shut-off flap seat ( 7 ) that is formed by components, the improvement wherein the components ( 2 ; 3 ; 8 , 12 a; 12 b ) of the shut-off device ( 1 ) that form the shut-off flap seat ( 7 ) have been subjected to treatment by cold ageing in the low temperature range.
2 . A shut-off device according to claim 1 , wherein said treatment cold ageing was conducted before final mechanical working of the components ( 2 ; 3 ; 8 , 12 a; 12 b ).
3 . A shut-off device according to claim 1 , wherein the components ( 2 ; 3 ; 8 , 12 a; 12 b ) were cold-aged by means of liquid nitrogen.
4 . A shut-off device according to claim 3 , wherein the components ( 2 ; 3 ; 8 , 12 a; 12 b ) were cold-aged in a liquid nitrogen bath.
5 . A shut-off device according to claim 1 , wherein the components ( 2 ; 3 ; 8 , 12 a; 12 b ) consist of CrNi steel.
6 . A shut-off device according to claim 1 , wherein the shut-off flap seat ( 7 ) is disposed between the shut-off flap ( 3 ) or at least one component ( 12 a; 12 b ) that is located on the shut-off flap ( 3 ) and the housing ( 2 ) or at least one component ( 8 ) that is located on the housing ( 2 ).
7 . A process for producing a shut-off device, especially a shut-off device for operating temperatures below 0° C., according to claim 1 , wherein before final mechanical working of the components ( 2 ; 3 ; 8 , 12 a; 12 b ) that form the shut-off flap seat ( 7 ), treating the components ( 2 ; 3 ; 8 , 12 a; 12 b ) by cold ageing in the low temperature range, done and heating the components ( 2 ; 3 ; 8 , 12 a; 12 b ) to the ambient temperature after cold ageing.
8 . A process according to claim 7 , wherein heating to the ambient temperature of the components ( 2 ; 3 ; 8 , 12 a; 12 b ) is done without a heating means.
9 . A process according to claim 7 , wherein cold ageing in the low temperature range and subsequent heating to ambient temperature constitutes a cycle and is carried out several times in succession.
10 . A process according to claim 9 , wherein the cycle is conducted 2-4 times.
11 . A process according to claim 9 , wherein the cycle is conducted 3 times.
12 . A shut-off device prepared according to claim 7 .
13 . A process according to claim 10 , wherein the cycle is conducted 3 times.
14 . A process according to claim 11 , wherein the cycle is conducted 3 times.