今天我们来讲解有关固定式球阀的结构特点及绍。如下：
1、全通径设计
按照客户的要求可以提供全通径或缩径阀门，全通径阀门具有与管子内径完全一致的通道直径，减少涡流便于清扫管道。
Full Bore Design
According to the customer's demand,the full bore or the reduced bore canbe provided.The full-bore valve hasthe diameter of channel completelyequal to the inner diameter of pipe tofacilitate to clean the pipe.
2、防火结构
万一发生火灾或异常升温使PTFE软化烧损时,阀座支承圈防火密封面可以和球体接触，起到密封作用且符合API6O7和API 6FA规范要求。
Fire-proof Structure
When the fire happens or thetemperature unusually rises tomake PTFE soften to damage,the fire proof seal surface ofseat supported circle cancontact with ball to have sealfunction.This conforms tothe requirements of API607and API 6FA.
3、阻塞与排泄功能
固定式球阀采用弹簧预紧，阀座密封为双活塞，利用活塞原理密封，上下游侧的阀座使流体阻断，阀体中腔装放空阀排空，阀底装有排污阀排污,便于管道清洗。
Block & Bleed Function
Fixed ball valve adopts spring to pre-tighten, and seat seal is double pistons.lt adopts piston principle to seal. Upstrean and downstream seats make fluidstop. and the emptying valve installedon the middle cavity is used to emptyand the blow down valve installed atthe bottom of valve to clear off dirt tofacilitate to clean the pipe.
4、密封的紧急救护
由于介质中的杂质或火灾造成阀座密封意外失败，注脂阀提供了与注脂枪的快速连接，方便快捷地将密封脂注入到阀座密封部位,缓解泄漏。
Urgent Help of SealDue to the dirt or fire makeunusual failure of seat seal,sealant-injection vave providethe quick connection withsealant-injection gun, andit is convenient to inject sealgrease into the seal part ofseat to reduce leakage.
5、自动泄压
阀门中腔停滞的介质由于温度升高而出现异常升压时，阀座出口端具有自动泄压功能，同时根据需要，阀体上可装安全阀，保证阀体具有自动泄压功能，确保管道安全。
Automatic Relief
When the medium in the middle cavityunusually raises pressure for the risingof temperature, outlet of seat hasautomatic relief function. At the same
time, according to tne ldn thesafety valve can be installed on the
body to ensure the automatic relieffunction of body. so that the pipecan be safe.
6、防静电设计
固定式球阀采用铬镍不锈钢的弹簧和小球使球体、阀杆和阀体之间相互导电，从而把静电完全释放。
Anti-static Design
Chrome and nickel stainlesssteel spring and small ballare adopted to make electroconductive among ball.Stemand body to comp latelyrelease static.
7、结构及特点
防操作的可靠性
大口径
固定式球阀的相对连动部(阀座和阀杆轴承)由于采用了摩擦系数小的特氟龙,因而操作扭距小，此外，由于密封润滑脂的长期产润滑，使得操作更加灵活。
Operational Reliability
For large ball valve, the TFE is adopted for seat and stem bearing,the relative movement at bearing portion requires less operationaltorque force because of less friction of the TFE, in addition, the longtime lubrication of the sealants makes the operation more effective.
阀座结构
阀座的结构有两种:单密封和双密封结构，一般具有自动泄压机能是单密封，双密封则由阀体上附加的安全泄压。
Seat Disign
There are tow kinds of seat design, single seal and double seal, theformer normally has self relief function, the latter relieves the pressurethrough the safety valve on the body.
阀杆加长
阀杆加长适用于埋地及低温用，加长尺寸根据需要确定，操作方式有手动、电动、气动、气液连动等。
Extended Stem
The extended stem is designed for underground and low temperatureservice, the length of stem depents on the service requirement. Theoperation methods include manual pneumatic-hydraulic etc.
对外力的安全性
阀体的壁厚根据高压容器的安全法规进行设计，对承受外力抗弯曲等符合API 6D规定，强度足够。
Safety on External Force
The body thinkness is designed in conformance to the requirementsof high-pressure vessel code and has enough strength As requiedby API 6D to prevent bucking induced external.
阀杆压盖部密封
填料压盖部密封如图所示采用了四个O型圈和密封注脂装置。
Sealing of Stem Gland
As shown in figure, the sealing of gland is accomplished byorrangement of four O-ring and a sealant injection device.
