Method for sealing tubes
AssigneeConsiglio Nazionale Delle Ricerche
InventorsFranco Pavese, Danilo Ferri
Life of this patent
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Abstract
The method allows the sealing of metal tubes, particularly of stainless steel, for example, tubes for filling containers for gas at high pressure or evacuation tubes for vacuum vessels. It includes the steps of locally squashing the portion of the tube to be sealed with a pressure capable of achieving the sealed clamping of the tube, freeing part of the squashed portion of the tube, the remaining part being maintained under the clamping pressure, cutting the freed part of the squashed portion of the tube, welding the lips of the part which is still clamped, and finally removing the clamping pressure.
Claims3
Method for sealing tubes of metal with a poor ductility, comprising:
- inserting a bush of ductile metal having an outer diameter substantially equal to the internal diameter of the tube into the tube;
- squashing the portion of the tube in which the bush is inserted with a pressure such as to achieve the sealed constriction of the tube and the bush;
- freeing part of the squashed portion of the tube while the remaining part is kept under the clamping pressure, the remaining part including part of the bush,
- cutting off the freed part of the squashed portion of the tube and the bush;
- welding the lips of the still-clamped part of the tube and the bush, and
- removing the clamping pressure.
Dependencies are inferred from the claim text.