| 摘要 |
<p>A circular series of expandable collet sections is fixed to the inner end of a collet tube positioned in the heat exchanger tube, the collet sections in registration with the tube support sheet. The outer end of the collet tube is fixed to a housing portion connected to a cylinder structure. A rod extends through the tube and has fixed to its outer end a tapered mandrel arranged in juxtaposition to the collet sections. A shaft is journaled in the cylinder structure and is connected to the outer end of the mandrel rod by motion transmitting means operable upon rotation of the shaft to move the rod and the mandrel inwardly to effect expansion of the collet sections in engagement with the heat exchanger tube for expansion of the same in the tube support sheet. The force exerted by the shaft on the mandrel rod is applied directly to a piston arranged in a closed prepressurized air-free hydraulic system. The hydraulic system is further pressurized by movement of the piston, effecting operation of a pressure indicating gauge in the system. Accordingly, the operator can readily expand all tubes in the heat exchanger to precisely the same extent.</p> |
