With the improvement of steam parameters in power plants, new requirements have been put forward for some gates on the main steam pipeline and water supply pipeline. They must withstand a series of problems caused by high temperature and pressure, such as the force on the components, thermal stress caused by temperature changes, and tightness.

高压阀门在运行中是否可靠，对发电厂的经济运行起着重要的作用。如高压阀门不能保证严密不漏，那么就不能切断介质的流通，该停止的设备就不能停下来，会造成严重的事故；又例如高压阀门阀盖上的法兰螺丝折断，会使阀盖飞出，造成重大 的事故等等。随着发电厂机组向大容盘，高参数方向发展，阀门也随着介质参数的提高，不断地向高温高压方向发展。

The reliability of high-pressure valves during operation plays an important role in the safe and economic operation of power plants. If the high-pressure valve cannot be guaranteed to be tight without leakage, then the flow of the medium cannot be cut off, and the equipment that needs to be stopped cannot be stopped, which can cause serious accidents; For example, if the flange screw on the high-pressure valve cover is broken, it can cause the valve cover to fly out, causing major accidents, and so on. With the development of power plant units towards large capacity and high parameters, valves continue to develop towards high temperature and pressure with the improvement of medium parameters.

管道介质工作压力的提高，要求阀门相应地改进密封结构，提高密封性能，采用新型密封面材料。为了简化管路系统出现了一阀多用的组合阀门， 如启动、减压和三用的组合阀门。随着自动控制的提高，实行集中控制和遥控，就对阀门的驱动装置和执行机构提出了新的要求。

The increase in working pressure of pipeline medium requires corresponding improvement of sealing structure and sealing performance of valves, and the use of new sealing surface materials. In order to simplify the pipeline system, a combination valve with multiple functions has emerged, such as a combination valve for starting, reducing pressure, and safety. With the improvement of automatic control and the implementation of centralized control and remote control, new requirements have been put forward for the driving device and actuator of valves.

高压闻门的构造型式大致与前面所讲的型式差不多，只是根据高压设备运行的经验进行某些改变，如其零件采用材料制成，提高加工的质量和精密度。高压闸阀大部分不用法兰连接，而是带有直接与管道焊接的端头。

The construction type of the high-pressure door is roughly similar to the one mentioned earlier, but some changes are made based on the experience of high-pressure equipment operation. For example, the parts are made of high-quality materials to improve the quality and precision of processing. Most high-pressure gate valves do not require flange connections, but instead have ends that are directly welded to the pipeline.