译文：
截止阀是指关闭件(阀瓣)沿阀座中心线移动的阀门。根据阀瓣的这种移动形式，阀座通口的变化是与阀瓣行程成正比例关系。由于该类阀门的阀杆开启或关闭行程相对较短，而且具有非常可靠的切断功能，又由于阀座通口的变化与阀瓣的行程成正比例关系，非常适合于对流量的调节。因此，这种类型的阀门非常适合作为切断或调节以及节流使用。 截止阀的选用原则是： 1、高温、高压介质的管路或装置上宜选用截止阀。如火电厂、核电站，石油化工系统的高温、高压管路上。 2、管路上对流阻要求不严的管路上。即对压力损失考虑不大的地方。 3、小型阀门可选用针阀、仪表阀、取样阀、压力计阀等。 4、有流量调节或压力调节，但对调节精度要求不高，而且管路直径又比较小，如公称通经≤50mm 的管路上，宜选用。 5、合成工业生产中的小化肥和大化肥宜选用公称压力PN160 公称压力16MPa 或PN320 公称压力32MPa 的高压角式截止阀或高压角式节流阀。 6、氧化铝拜耳法生产中的脱硅车间、易结焦的管路上，易选用阀体分开式、阀座可去处的、硬质合金密封副的直流式截止阀或直流式节流阀。 7、城市建设中的供水、供热工程上，公称通经较小的管路，可选用截止、平衡阀或柱塞阀，如公称通经小于150mm的管路上。 最明显的优点是： 在开启和关闭过程中，由于阀瓣于阀体密封面间的摩擦力比闸阀小，因而耐磨。 开启高度一般仅为阀座通道直径的1/4，因此比闸阀小的多。 通常在阀体和阀瓣上只有一个密封面，因而制造工艺性比较好，便于维修。 公称压力或压力级：PN1.0-16.0MPa、ANSI CLASS 150-900、JIS10-20K 公称通径或口径：DN10～500、NPS 1/2 ～36" 连接方式：法兰、对焊、螺纹等适用温度：-196℃～700℃ 驱动方式：、气动、电动、液动、气液联动、阀体材料：WCB、ZG1Cr18Ni9Ti、ZG1Cr18Ni12Mo2Ti、CF8(304)、CF3(304L)、CF8M(316)、CF3M(316L)、Ti。选用不同的材质，可分别适用于水、蒸汽、油品、硝酸、醋酸、氧化性介质、尿素等多种介质

“ Selection of the principle of cut-off valve ”是由提供的国际阀门新闻，译文仅供参考。另外，中国截止阀网还提供相关产品搜索：、、、、等。

原文：
Cut-off valve is closed parts (valve flap) along the center line to move the valve seat. According to this mobile form of flap valves, valve seat openings change is in direct proportion with the valve flap between trips. As such the valve stem to open or close the relatively short trip, but also has a very reliable and cut-off function, and because changes in the valve seat and valve openings in direct proportion to the relationship between the trip valve is very suitable for flow regulation. Therefore, this type of valve is very suitable as cut or adjust, as well as the use of throttle. Selection of cut-off valve principle is: 1, high temperature, high pressure pipeline medium or device should use cut-off valve. Fiery power plants, nuclear power plants, oil and chemical system for high-temperature, high pressure pipeline. 2, pipe convective resistance on the road not strict pipeline. Namely, pressure loss is not considered places. 3, small needle valve can be selected, instrument valves, sampling valves, pressure gauge valve. 4, there are flow control or pressure regulation, but regulation accuracy not ask for much, but also the relatively small diameter pipes, such as the nominal possession of the road by ≤ 50mm advised to use. 5, synthetic industrial production of small and large fertilizer fertilizer should choose Nominal pressure PN160 or PN320 PN 16MPa Nominal pressure 32MPa high-pressure angle-type stop valve or high-pressure angle-type throttle. 6, alumina Bayer production desiliconization workshop, easy to coke possession of the road, easy to use separate valve type, valve seat can be place, and carbide seal pair of DC-style cut-off valve or DC-type throttle valve. 7, urban construction, water supply, heat supply engineering, the nominal pass through a smaller pipeline, the choice of closing, balance valve or a plunger valve, such as the nominal pipe through the road is less than 150mm. The most obvious advantages are: the opening and closing process, the valve flap in the body due to friction between the sealing surface smaller than the gate valve, thus wear. Seat height is typically only open channel diameter of 1 / 4, so more smaller than the gate. Usually in the valve body and valve flap is only one sealing surface, thus comparison of manufacturing processes is good, easy to repair. Nominal pressure or stress level: PN1.0-16.0MPa, ANSI CLASS 150-900, JIS10-20K Nominal diameter or caliber: DN10 ~ 500, NPS 1 / 2 ~ 36 "Connection: flange, butt welding, thread, etc. Suitable temperature: -196 ℃ ~ 700 ℃ Drive Mode:, pneumatic, electric, hydraulic, gas-liquid linkage, Body material: WCB, ZG1Cr18Ni9Ti, ZG1Cr18Ni12Mo2Ti, CF8 (304), CF3 (304L), CF8M (316), CF3M (316L), Ti. selection of a different material, may be separately applied to water, steam, oil, nitric acid, acetic acid, oxidizing medium, urea and other media