二、结构特点
1、中线蝶阀为整个蝶板与阀座在360°圆周内同心(中线)，具有双向密
封功能，压力、流量可自由调节。
2、四级加载弹性密封，绝对保证了阀门内、外的零泄漏。
A、轴头、蝶板园周连接处的特殊过渡曲线与阀座的合理过盈。
B、轴头端面采用弹性O型圈和轴肩处刚性垫圈、弹性橡胶垫组合。
C、轴的径向采用O型圈与金属垫的组合。
D、阀座镶在有弹性条的阀体槽内。
3、采用可调弹性弹子定位，定位准确，结构简单。
三、设计规范
遵循GB 12238，API609，MSS SP-67，MSS SP-68标准。
四、驱动方式
手动、蜗轮传动、气动、电动。
Disc, the trim part of butterfly valves, rotates with the stem to open/close and modulate the valve.
Butterfly valves can cut off or throttle the circulation of medium. So, recently, the sealing performance is becoming more and more important characteristics. Better sealed, better sales. Small in size, light weight and simple structure, butterfly valve is 30 to 50 percent lighter, at average, compared to gate valve. It can rotate the disc 90 degrees to close or open the valve. The torque of butterfly valve is small because the force exerted on both side of disc is approximately equal and in opposite directions.
1. Fluoroplastic Lined Butterfly Valve of This company
1)There are two basic types of fluoroplastic lined butterfly valves, fully lined wafer type butterfly valve, such as D71F4, D71F46, and fully lined flanged type butterfly valve, such as D41F4, D41F46. Both of the two types valves are centred lined. With two-piece body, integration of lined body and seat, the valve is corrosion resistant of any kind of medium, except molten alkali carbonate and fluorin, because the whole valve, except fluoroplastic seat and fluoroplastic lined disc, would not have any direct contact with the medium. Especially for D71F46, the disc and stem is forged in integration, coated with FEP. The valve is easy to be zero leakage because of smooth inside surface, small fluid resistance, high CV value, quick flow, small torque, class IV sealing structure and special sealing face.
The special sealing face is equipped with heat resistant and aging resistant gasket made of silicone rubber.
2)The above model number D41F4 and D41F46 is about flanged ends semi lined butterfly valve, with fully lined body and stainless steel disc.
2. Characteristics of Structure
1)The whole disc is concentric with seat in 360 degrees. Butterfly valve is mainly applied to stop, distrubute and change flowing direction of medium.
2)Class IV sealing is the guarantee of zero leakage.
A.Joint of axil and the edge of disc has special treatment. So does the seat.
B.End of axil is with O-ring and between the axil there are rigid gasket and rubber gasket.
C.The O-ring and metallic gasket is added in the radial of axil.
D.Seat is inserted in the body.