Torque Analysis Of Globe Valve

During the closing phase of the globe valve from the fully open position, as the disc drops, the fluid creates a differential pressure before and after the disc to prevent the disc from falling, and this resistance increases rapidly as the disc drops. When the globe valve is fully closed, the pressure difference between the front and back of the disc is equal to the working pressure of the medium, and the resistance is the largest. With forced sealing force, the operation force at the moment of closure of the globe valve increases rapidly. During valve opening, thrust due to medium pressure or differential pressure between the front and back of the disc helps to open the valve. It should be noted that the torque at the moment of valve opening may exceed that at the moment of valve closing because of the greater static friction force to be overcome. When the globe valve is opened, the opening height of the disc reaches 25% ~ 30% of the nominal diameter of the globe valve, the flow rate has reached the maximum, which indicates that the globe valve has reached the fully open position, so the fully open position of the globe valve should be determined by the disc stroke. The closing and re-opening of the globe valve is similar to that of the forced sealed gate valve, so the closing position of the globe valve should be determined by increasing the operating torque to the specified value.