主要用于气体、大口径水管线及蒸汽等介质管路中, 防止倒流, 控制阀启闭部件除靠介质流动自行关闭以外，还通过弹簧复位执行机构强制关闭，以避免关闭力矩不够，倒流带来危害，工作压力高时，还可加装液压缓闭装置，防止水锤、气锤损害设备。

主要特点：

阀体采用大偏心的三偏心蝶型阀结构，蝶板形成重锤自动关闭。
不需要外加重锤，减少流阻损失，通过弹簧复位气缸，提供力矩助关。
金属密封启闭零泄漏，耐冲涮，抗创击，必要时加装，液压缓闭系统。 
介质回流压力加上弹簧助关，确保阀门止回的密封性能。
角行程动作，轴向填料密封确保不渗漏 。

It mainly used to pipeline on gas, steam and so on to prevent regorging.Depending on the operating medium itself to close, besides, it can be closed forcibly by the spring return actuator, avoiding dangerous by flow backwards. If the working pressure is too high, we can fix hydraulic pressure sets to prevent water hammer and air hammer from damaging equipments.
 
Main characteristic: 
The body valve is three eccentric butterfly structures, the disc can became a hammer to close automatically. 

Reducing flow block without hammer. Spring return cylinder helps to offer torque.

Metal seated reaches zero leakage
Flow backwards of operating medium and spring return guarantees valve’s seal.
Angle action 

气动金属密封蝶型主动式止回阀
Metal seated Butterfly pneumatic check valve
 
结构性能特点structure characters

 
大偏心轴设计形成重锤自动关闭
在三偏心结构基础上，阀轴偏置距离加大，将蝶板一端形成重锤，可以自动关闭阀门，同时加装辅助气动弹簧关闭系统，在介质回流压力不够时，在未回流前将蝶板预先关闭，确保止回和减免水锤现象的发生。
  
Eccentric axial design
　On the base of the Eccentric triple structure, it makes the stem wider than before, which produce a hammer makes the valve close automatically. At the same time, it sets assistant pneumatic spring system, ensures safety and decrease water hammer.

无滑动磨损实现长寿命

斜锥面金属密封蝶阀设计采用了一个双偏心和一个特殊斜锥椭圆密封结构，实现蝶板在开启瞬间密封面即分离，关闭接触即密封的效果，这种密封结构实现启闭无机械滑动摩擦，大大延长了密封件的使用寿命, 并且达到启闭轻松自如目的，且具有密封自动补偿功能。

No slip friction Realizing long service life.
The Metal seated butterfly valve adopts a double eccentric structure and a inclined cone seal. The seal-ring can be separated once open the disk, and the valve can be sealed once the seal-ring contacts the disk. This structure can decrease the friction torque when the butterfly valve opens and closes, and expanded the life time, and make opening and closing easily.