Bellows gate valves are forced sealing valves, so when the valve is closed, pressure must be applied to the disc to force the sealing surface not to leak. When the medium enters the valve body from below the disc, the resistance to be overcome by the operation force is the friction force of the stem and packing and the thrust generated by the pressure of the medium. The force of closing the valve is greater than the force of opening the valve, so the diameter of the valve stem is large, otherwise the fault of the stem top bend will occur. In recent years, from the emergence of the sealing valve, the flow of the globe valve medium by the disc above the valve chamber, then under the medium pressure, the force of closing the valve is small, and the force of opening the valve is large, the diameter of the valve stem can be reduced accordingly. At the same time, under the action of the medium, this form of valve is also tight.
China's valves "three to" once stipulated, the flow of cut-off valve, all from top to bottom.
When the bellows GATE valve IS opened, the opening height of the valve disc is 25% ~ 30% of the nominal diameter, and the flow rate has reached the maximum, indicating that the valve has reached the fully open position. So the full open position of the globe valve should be determined by the stroke of the valve disc. Electric gate valves are responsive, safe and reliable. Many plants with high control requirements set up compressed air stations for pneumatic instrument control components. Electric means electric. And a device that can control its flow.
First, what is the electric valve [/title] electric valve is simply to control the valve with an electric actuator, so as to realize the opening and closing of the valve. It can be divided into two parts, the upper part is the electric actuator, the lower part is the valve.