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.

高壓閥門在運(yùn)行中是否可靠，對(duì)發(fā)電廠的經(jīng)濟(jì)運(yùn)行起著重要的作用。如高壓閥門不能保證嚴(yán)密不漏，那么就不能切斷介質(zhì)的流通，該停止的設(shè)備就不能停下來(lái)，會(huì)造成嚴(yán)重的事故；又例如高壓閥門閥蓋上的法蘭螺絲折斷，會(huì)使閥蓋飛出，造成重大 的事故等等。隨著發(fā)電廠機(jī)組向大容盤，高參數(shù)方向發(fā)展，閥門也隨著介質(zhì)參數(shù)的提高，不斷地向高溫高壓方向發(fā)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.

管道介質(zhì)工作壓力的提高，要求閥門相應(yīng)地改進(jìn)密封結(jié)構(gòu)，提高密封性能，采用新型密封面材料。為了簡(jiǎn)化管路系統(tǒng)出現(xiàn)了一閥多用的組合閥門， 如啟動(dòng)、減壓和三用的組合閥門。隨著自動(dòng)控制的提高，實(shí)行集中控制和遙控，就對(duì)閥門的驅(qū)動(dòng)裝置和執(zhí)行機(jī)構(gòu)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.

高壓聞門的構(gòu)造型式大致與前面所講的型式差不多，只是根據(jù)高壓設(shè)備運(yùn)行的經(jīng)驗(yàn)進(jìn)行某些改變，如其零件采用材料制成，提高加工的質(zhì)量和精密度。高壓閘閥大部分不用法蘭連接，而是帶有直接與管道焊接的端頭。

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.