摘要： 引水式电站的压力钢管抗外压失稳破坏问题应引起重视，尤其是在压力钢管道放空过程中，应注意控制放空速率和设置相应的补气装置，这类问题在小水电站增效扩容建设中比较多见，应避免类似情况的发生。

Abstract: The instable failure of penstock under pressure of diversion-type hydropower station calls for attention. Especially in the drainage process, the rate of draining water and air supply should be controlled carefully, to prevent the damage to penstocks.