Note：
　　 　　 DN50（2")-600(24")Type"Lug"butterfly valves are suitable for the pressure grade of PN1.0MPa separately.Two dimensions in one culumn show the connection dimensions of PN1.0/PN1.6MPa pressure grade.The upper flanges of the butterfly valves accommodates all types of operaters:manual,wormgear,electric and pneumatic actuators. 　　Difference between Type"Wafer"and"Lug":Both Type"Wafer"and"Lug"have the same construction and performances and are made of the same materials.The main difference between them is that type"Wafer"valves are mounted between pipe flanges (Wafer type)by bolts (or extended hexagon-head bolts),while type"Lug"can be either mounted between two pipes by ordinary hexagon head bolts or mounted on the pipe end (Lugged-type).As the valve is used at the end of pipe line.It is necessary to indicate in order.

为更好保证阀门的密封性能，法兰必须采用对夹蝶阀专用法兰。
若用户需要我公司配套法兰，请提供以下技术参数：
1.侧法兰连接标准
2.公称通径及管子外径
3.公称压力
4.法兰类型
5.密封面形式
6.法兰材质

Cv=当阀门全开时，阀两端压差为1磅/英寸2，流体用60°F的清水时，通过阀门的美加仑/分的流量数。
CV=Q√(G/△P)

其中：G=比重，清水为1.0
　　　Q=最大流量
　　　ΔP=压力差，1b/1n2
C=当阀门全开时，阀两端压差为100KPa（1Kg/cm2),流动用常温清水时，某给定行程的流量以m3/h计，介质密度取Kg/m3的流量数值（m2).
Cv=1.17C