A widely used device that regulates the flow in a pipe. It consists of a vertical moving section across the flow area. They are useful for on–off type flow control operations and provide a low pressure drop when fully open.
科学参考收录了60776条科技类词条，基本涵盖了常见科技类参考文献及英语词汇的翻译，是科学学习和研究的有利工具。