Brief Introduction to Ball Valve
Ball valve and Plug Valve are belong to same Type, While the Closure member is a ball. it rotates as the center line of valve to realize opening or closing the valve.
Ball valve is mainly used for chutting off, distributing or changing the direction of flow. it's widely used in recently years. it's with the features of Low hydraulic resistance, the resistance coefficient is equal to the pipe of same length. Simple Structure, Small size and light weight. Reliable seal performance, most of seal materials are plastic, good seal performance. and widely used in the vacuum system either.
- Easy to operate, switch swiftly. 90 degree rotating to control open and close, convienent to remote control.
- Easy to maintance, ball valve have simple structure, seal ring normally are moveable.
- When fully closed or opened, the ball and seat surface are compeletely seperated, the seal surface won't be corroded by media.
- Wide range of application. diameter from milimeter to meter. pressure from vacuum to high pressure.
Ball valve has been widely used in the petroluem, chemical, electricity generating, paper making, avaition, rockets and other industries,. even in the daily life of us. Ball valve could divided into following types by it's structure.
Ball valve could divided into straight-through type, three type, and right angle type. the latter two type used for distribute media or change the direction of media.
- Float ball valve, the vall is floating, under the pressure of media, the valve will move and push seat to the seal surface. to ensure the outlet sealed tightly. float ball valve has simple structure, good seal performance, while the working media pass all pressure to the outlet seal ring. so it's important to know the seal ring could bear the working load. and this structure is widely used for low or medium pressure ball valve.
- Fixed ball valve, the vall is fixed. it won't move under pressure, this valve with a floating seat, the seal will be moved and pressed on the ball sureface tightly. normally, to guanrantee seal performance, the valve have up and down shaft. this makes low torque and suitable for high pressure and large diameter valve. to further reduce the operating torque and reliability, recent years oil seal ball valve appears, that realized by adding lubricating oil, forming a oil membrane, not only strengthern the seal performance, but also lower operating torque. it's more suitable for large diameter ball valve.
- Elastic Ball valve. the ball is elastic, the seal ring adopting metal materials. pressure difference is large, it can not meet the seal requirement based on the pressrue of media. it must apply force. this valve suitable for high temperature and high pressure media. Below the inner wall of ball has a elastic groove, makes it elastic, when channel closed, the shaft wedge head opend and press seat to realize seal, befor ball rotating the wedge head relased, and ball and seal will have a gap between them. to reduce the friction and torque.
Ball valve could divided into straight-through type, three type, and right angle type. the latter two type used for distribute media or change the direction of media.