| 摘要 |
<p>A DEVICE FOR STOPPING A LEAK IN A STRAIGHT PORTION OF A HEAT-EXCHANGER TUBE An axial mandrel having good electrical conductivity is fitted with conical metal washers and insulating pastilles in alternate sequence. A nut applied against an insulating support at the lower end of the mandrel exerts a compressive stress on the washers, the peripheral edges of which are applied against a lining sleeve placed within a leaky portion of a heat-exchanger tube. Each washer thus exerts a radial force which applies the sleeve in intimate contact with the tube along a number of circular lines corresponding to the number of washers. An electric current is passed through the mandrel, the washers, the lining sleeve, thus uniting the tube and the lining sleeve by means of circular resistance welds.</p> |
