使用场合：

　　Usage scenario:

　　阀门广泛应用于流体输送系统中，用于控制空气、水、蒸汽、各种腐蚀性介质、泥浆、油品、液态金属和放射性介质等各种类型流体的流动。

　　Valves are widely used in fluid transportation systems to control the flow of various types of fluids such as air, water, steam, various corrosive media, mud, oil, liquid metals, and radioactive media.

　　具体应用包括但不限于截断类（如闸阀、截止阀等）、止回类（用于阻止介质倒流）、调节类（调节介质的压力和流量）、类（在介质压力超过规定值时排放多余的介质）以及分配类（改变介质流向）等。

　　Specific applications include but are not limited to shut-off valves (such as gate valves, globe valves, etc.), check valves (used to prevent medium backflow), regulating valves (regulating the pressure and flow rate of the medium), safety valves (discharging excess medium when the medium pressure exceeds the specified value), and distribution valves (changing the flow direction of the medium).

　　高压阀广泛适用于石油、化工、电力、冶金、航空等各个领域的高压设备中，如锅炉、压缩机、管道、容器等，保护设备免受过压，防止发生爆炸等危险事故。

　　High pressure safety valves are widely used in high-pressure equipment in various fields such as petroleum, chemical, power, metallurgy, aviation, etc., such as boilers, compressors, pipelines, containers, etc., to protect equipment from overpressure and prevent dangerous accidents such as explosions.

　　阀门的选择不仅基于其压力范围，还考虑工作温度、介质特性以及特定的工业应用要求。例如，高温阀工作温度≥450℃，中温阀120℃≤工作温度<450℃，常温阀-40℃≤工作温度<120℃，低温阀-100℃≤工作温度<40℃，超低温阀工作温度<-100℃。此外，阀门的材质也是选择的关键因素，包括铸铁、铸钢、不锈钢（201、304、316等）、铬钼钢、铬钼钒钢、双相钢、塑料等。

　　The selection of valves is not only based on their pressure range, but also takes into account working temperature, medium characteristics, and specific industrial application requirements. For example, high-temperature valves have a working temperature of ≥ 450 ℃, medium temperature valves have a working temperature of 120 ℃ ≤<450 ℃, normal temperature valves have a working temperature of -40 ℃ ≤<120 ℃, low-temperature valves have a working temperature of -100 ℃ ≤<40 ℃, and ultra-low temperature valves have a working temperature of<-100 ℃. In addition, the material of the valve is also a key factor in the selection, including cast iron, cast steel, stainless steel (201, 304, 316, etc.), chromium molybdenum steel, chromium molybdenum vanadium steel, duplex steel, plastic, etc.