扭矩参数
Torque Data

蝶阀扭矩参数
Butterfly Valve Torque Data

　　扭矩是操作阀门所需的旋转作用力。蝶阀上的这种旋转作用力取决于三个因素：(1)阀瓣与阀座密封的摩擦力；(2)轴承摩擦力；(3)动力矩。
　　Torque is the rotary effort required to operate a valve. This turning force in a butterfly valve is determined by three factors. (1) Friction of the disc to seat for sealing (2) Bearing friction (3) Dynamic torque.
　　最小启动力矩是在某个压差下，轴承摩擦力和阀座/阀瓣干扰摩擦力所产生的扭矩的总和。这个值通常是操作阀门所需扭矩的最大值，用于决定执行机构的选型。左侧所列的参数值是通过性能试验而得到的，包括了保险余量。所列的扭矩值对于常温下的水和润滑液体有效。对于干燥或非润滑液体的扭矩值，请咨询美国尼伯科公司的用户服务代表。
　　Breakaway Torque is the total of the torques resulting from bearing friction and seat/disc interference friction at a given pressure differential. This value is normally the highest required torque to operate a valve, and is used in sizing actuators. The values listed at the left are based on performance tests and include a safety factor. The torques listed are valid for water and lubricating fluids at ambient temperature. For dry and non-lubricating fluids, contact your NIBCO customer service representative.
　　通径DN200以上的蝶阀应用于液体时，倾向于关闭阀门的动力矩明显增加。由于这种原因，推荐使用齿轮操作机构或执行机构。
　　Butterfly valves, sizes 8" and larger, when used on liquids, show a marked increase in dynamic torque which tends to close the valve. For this reason, gear operated or actuated valves are recommended.
　　所列扭矩适用于EPDM(三元乙丙橡胶)。在计算适用于Buna-N(腈基丁钠橡胶)或氟橡胶的扭矩时，请对所列的扭矩值乘以1.25。对于应用于干燥流体介质的阀门的扭矩值，请咨询工厂。
　　Torque listed for EPDM. When calculating torques for Buna-N, or Fluoroelastomer multiply listed torque by 1.25. Consult factory for dry service valves.