| 摘要 |
<p>The invention relates to a plug (4) for sealing faulty heat-exchanger tubes (2, 3) with a plug jacket (9), the outside diameter of which can be enlarged and which can be sealingly pressed against the inside tube wall. In non-steady-state operating conditions, it can happen that heat exchanger tubes sealed in this manner become temporarily leaky, receive small quantities of primary medium and this primary medium generates an excess pressure in the sealed heat exchanger tubes which endangers these tubes. To counteract this, the invention provides a pressure relief line (20, 24, 28 to 32) which penetrates through the plug (4) in the longitudinal direction and which is provided with a closure (21 to 25) which opens with a predetermined excess pressure in the heat exchanger tube. In addition, a spring-loaded valve (21 to 25) can be inserted in the pressure relief line (32). A plug according to the invention is particularly suitable for being used to seal faulty heat exchanger tubes. <IMAGE></p> |
