The feeding gate is a proportional valve, that is, a valve that can control the switching speed of the valve. The proportional valve has a pilot valve, and the pilot valve must be energized whether the valve is opened or closed. The proportional valve is a valve controlled by 4~20mA signal, 4~12mA controls the valve to close, and 12~20mA controls the valve to open.Vacuum Hardening Stainless Steel The absolute value of the difference between the current and 12mA determines the speed of the valve action. The larger the absolute value of the difference, the faster the valve action; the smaller the absolute value of the difference, the slower the valve action.Sintering of B4C by Pressureless Liquid Phase Sintering Unloading gate operation screen: The computer controls the power on and off of the pilot valve and the input current of the proportional valve by comparing the set value of the blanking gate with the actual value of the blanking gate, so as to realize the precise positioning of the blanking gate. That is to say, when the deviation between the set value and the actual value is less than 100 degrees, there is no need to adjust the opening degree, and the unloading gate will not act. When the deviation between the set value and the actual value is greater than degrees, and the set value is greater than the actual value, the valve is opened; when the deviation between the set value and the actual value is greater than degrees, and the set value is less than the actual value, the valve is closed. Vacuum Heat Treatment of Fasteners There are 3 speed gears for forward and reverse valve action, which are high speed, medium speed and low speed respectively. The larger the deviation value is, the faster the valve action speed will be. When the difference between the actual angle and the set angle is greater than 8 degrees, use high speed, when it is 4~8 degrees, use medium speed, and when it is less than 4 degrees, use low speed.Vacuum sintering of transparent ceramics