Electric valve manufacturers teach you how to calculate the torque of the valve. Shanghai Lianggong valve torque is the force that makes the object rotate. The torque of the engine refers to the torque output by the engine from the crankshaft end. Under the condition of fixed power, it is inversely proportional to the engine speed. The faster the speed is, the smaller the torque is, and vice versa. It reflects the load capacity of the vehicle in a certain range.

阀门扭矩计算具体是：二分之一阀门口径的平方×3.14得出是阀板的面积，再乘以所承压力（即阀门工作压力）得出轴所承受的静压力，乘以磨擦系数（去查表一般钢铁的磨擦系数取0.1，钢对橡胶的磨擦系数取0.15），乘以轴径除以1000即得阀门的扭矩数，单位为牛·米，电动装置和气动执行器参考值取阀门扭矩的1.5倍。

The calculation of valve torque is: the square of one-half of the valve diameter × 3.14 the area of the valve plate is obtained, and then multiplied by the bearing pressure (i.e. the working pressure of the valve) to obtain the static pressure borne by the shaft, multiplied by the friction coefficient (refer to the table, the friction coefficient of general steel is 0.1, and the friction coefficient of steel to rubber is 0.15), multiplied by the shaft diameter divided by 1000 to obtain the torque of the valve, in n · M, The reference safety value of electric device and pneumatic actuator is 1.5 times of valve torque.

阀门在设，选用执行器是靠估算，基本分为三部分：

When designing the valve, the selection of actuator is based on estimation, which is basically divided into three parts:

1、密封件见的摩擦力矩（球体与阀座）

1. Friction torque of seal (ball and valve seat)

2、填料对阀杆的摩擦力矩

2. Friction torque of packing to valve stem

3、轴承对阀杆的摩擦力矩

3. Friction torque of bearing to valve stem

故计算压力一般取公称压力的0.6倍（约为工作压力），摩擦系数根据材料定。计算的力矩乘1.3~1.5倍以选执行器。阀门扭矩计算要兼顾阀板与阀座的摩擦，阀轴与填料的摩擦，介质不同压差下对阀板的推力。

Therefore, the calculated pressure is generally 0.6 times of the nominal pressure (about the working pressure), and the friction coefficient is determined according to the material. Multiply the calculated torque by 1.3 ~ 1.5 times to select the actuator. The valve torque calculation shall take into account the friction between the valve plate and the valve seat, the friction between the valve shaft and the packing, and the thrust of the medium on the valve plate under different differential pressure.

因为阀板、阀座和填料的种类太多了，每一种都有着不同的摩擦力，还有接触面的大小，压紧的程度等等。所以一般都是用仪表实测而不是计算。

Because there are too many types of valve plate, valve seat and packing, each of which has different friction, as well as the size of contact surface, compression degree and so on. Therefore, it is generally measured with instruments rather than calculated.