進(jìn)口截止閥分類與選型
進(jìn)口截止閥是指關(guān)閉件（閥瓣）沿閥座中心線移動(dòng)的閥門。根據(jù)閥瓣的這種移動(dòng)形式，閥座通口的變化是與閥瓣行程成正比例關(guān)系。由于該類閥門的閥桿開(kāi)啟或關(guān)閉行程相對(duì)較短，而且具有非常可靠的切斷功能，又由于閥座通口的變化與閥瓣的行程成正比例關(guān)系，非常適合于對(duì)流量的調(diào)節(jié)。因此，這種類型的閥門非常適合作為切斷或調(diào)節(jié)以及節(jié)流使用。
進(jìn)口截止閥主要分為三類：直通式截止閥、直角式截止閥及直流式斜截止閥 截止閥最明顯的優(yōu)點(diǎn)是：在開(kāi)啟和關(guān)閉過(guò)程中，由于閥瓣于閥體密封面間的摩擦力比閘閥小，因而耐磨。開(kāi)啟高度一般僅為閥座通道直徑的 1/4，因此比閘閥小的多。通常在閥體和閥瓣上只有一個(gè)密封面，因而制造工藝性比較好，便于維修。
進(jìn)口截止閥公稱壓力或壓力級(jí)：PN1.0-16.0MPa、ANSI CLASS150-900、JIS 10-20K，公稱通徑或口徑：DN10~500、NPS 1/2~36"，截止閥連接方式：法蘭（法蘭截止閥）、對(duì)焊（焊接截止閥）、螺紋（螺紋截止閥）等，適用溫度：-196℃~700℃，截止閥驅(qū)動(dòng)方式：手動(dòng)、傘齒輪傳動(dòng)、氣動(dòng)、電動(dòng)、液動(dòng)、氣液聯(lián)動(dòng)、電液聯(lián)動(dòng)，閥體材料：WCB、ZG1Cr18Ni9Ti、ZG1Cr18Ni12Mo2Ti、CF8(304)、CF3(304L)、 CF8M(316)、CF3M(316L)、Ti。有碳鋼截止閥、不銹鋼截止閥、鉻鉬鋼高溫高壓截止閥。截止閥選用不同的材質(zhì)，可分別適用于水、蒸汽、油品、硝酸、醋酸、氧化性介質(zhì)、尿素等多種介質(zhì)。
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 link age, 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 mobile 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.