进口截止阀分类与选型
进口截止阀是指关闭件（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。
进口截止阀主要分为三类：直通式截止阀、直角式截止阀及直流式斜截止阀 截止阀的优点是：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。
进口截止阀公称压力或压力级：PN1.0-16.0MPa、ANSI CLASS150-900、JIS 10-20K，公称通径或口径：DN10~500、NPS 1/2~36"，截止阀连接方式：法兰（法兰截止阀）、对焊（焊接截止阀）、螺纹（螺纹截止阀）等，适用温度：-196℃~700℃，截止阀驱动方式：手动、伞齿轮传动、气动、电动、液动、气液联动、电液联动，阀体材料：WCB、ZG1Cr18Ni9Ti、ZG1Cr18Ni12Mo2Ti、CF8(304)、CF3(304L)、 CF8M(316)、CF3M(316L)、Ti。有碳钢截止阀、不锈钢截止阀、铬钼钢高温高压截止阀。截止阀选用不同的材质，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。
Cut-off valve Cut-off valve is divided into three categories: straight-through globe valve, angle valve and DC oblique cut-off valve. The most obvious advantage is: the process of opening and closing the valve between the valve sealing surface friction is smaller than the gate, and therefore wear. The opening height is typically only 1/4 of the diameter of the seat channel, and therefore much smaller than the gate. Usually only one on the valve body and disc sealing surface, and thus manufacturing processes, ease of maintenance. Globe valve Nominal pressure or the pressure levels: PN1.0-16.0MPa the ANSI CLASS150-900, JIS 10-20K, the nominal diameter or caliber: DN10 ~ 500, NPS 1/2 to 36 "cut-off valve connection: Flange , butt, thread, etc. applicable Temperature: -196 ℃ ~ 700 ℃, the stop valve drive mode: Manual, bevel gear, pneumatic, electric, hydraulic, pneumatic, electro-hydraulic linkage, body material: WCB, ZG1Cr18Ni9Ti , ZG1Cr18Ni12Mo2Ti, CF8 (304), CF3 (304L), CF8M (316), CF3M (316L), Ti. stop valve choice of different materials can be separately applied to water, steam, oil, nitric acid, acetic acid, oxidizing medium , urea and other media. Off valve is shut down parts (disc) moving the valve along the valve seat centerline. According to this form of the valve, the seat through the mouth of the change is directly proportional relationship with the valve stroke. The type of the valve stem to open or close the trip is relatively short, but very reliable cut, due to changes in the valve seat openings and the valve stroke is proportional to the very suitable for flow regulation. Therefore, this type of valve is suitable as a cut or adjust the throttle use.