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.

閥門扭矩計算具體是：二分之一閥門口徑的平方×3.14得出是閥板的面積，再乘以所承壓力（即閥門工作壓力）得出軸所承受的靜壓力，乘以磨擦系數（去查表一般鋼鐵的磨擦系數取0.1，鋼對橡膠的磨擦系數取0.15），乘以軸徑除以1000即得閥門的扭矩數，單位為牛·米，電動裝置和氣動執行器參考值取閥門扭矩的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.

閥門在設，選用執行器是靠估算，基本分為三部分：

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

1、密封件見的摩擦力矩（球體與閥座）

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

2、填料對閥桿的摩擦力矩

2. Friction torque of packing to valve stem

3、軸承對閥桿的摩擦力矩

3. Friction torque of bearing to valve stem

故計算壓力一般取公稱壓力的0.6倍（約為工作壓力），摩擦系數根據材料定。計算的力矩乘1.3~1.5倍以選執行器。閥門扭矩計算要兼顧閥板與閥座的摩擦，閥軸與填料的摩擦，介質不同壓差下對閥板的推力。

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.

因為閥板、閥座和填料的種類太多了，每一種都有著不同的摩擦力，還有接觸面的大小，壓緊的程度等等。所以一般都是用儀表實測而不是計算。

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.