Valves in Ductile Iron, Cast Steel & Stainless Steel
27
2025
-
10
Introduction to J41 Cast Steel Globe Valve
Author:
Globe valves belong to forced sealing valves, so when the valve is closed, pressure must be applied to the valve disc to force the sealing surface not to leak.
Globe valves belong to forced sealing valves, so when the valve is closed, pressure must be applied to the valve disc to force the sealing surface not to leak. When the medium enters the valve from below the valve disc, the resistance that the operating force needs to overcome is the frictional force between the valve stem and the packing, as well as the thrust generated by the pressure of the medium. The force required to close the valve is greater than the force required to open it, so the diameter of the valve stem should be larger, otherwise the valve stem bending fault may occur. In recent years, with the emergence of self sealing valves, the flow of medium in shut-off valves has shifted from above the valve disc into the valve chamber. Under the pressure of the medium, the force required to close the valve is small, while the force required to open the valve is large, resulting in a corresponding reduction in the diameter of the valve stem. Meanwhile, under the influence of the medium, this type of valve is also relatively tight. The "Three Modernizations" of valves in our country once stipulated that the flow direction of globe valves should be from top to bottom. When the shut-off valve is opened and the opening height of the valve disc is 25% to 30% of the nominal diameter, the flow rate has reached a large level, indicating that the valve has reached the fully open position. So the fully open position of the shut-off valve should be determined by the stroke of the valve disc.
One-Stop Valve Production Specialist
CONTACT US
No. 85 Xiangyang Road, Weicheng District, Weifang City, Shandong Province, China