Selection of stop valves

Disadvantages of globe valves: ① High fluid resistance. The medium flow path inside the valve body is quite tortuous, resulting in higher energy consumption. However, the fluid resistance of DC stop valves is relatively low ； ②The opening and closing torque is high, making it difficult to operate. When closing, since the movement direction of the valve disc is generally opposite to the direction of the medium pressure, it is necessary to overcome the force exerted by the medium, resulting in a high opening and closing torque. For high- and medium-pressure stop valves with large diameters, a balanced design can be used to reduce the torque required for opening and closing ； ③The direction of medium flow is restricted. It is generally required that the medium flow from top to bottom. . Structural types of stop valves: The structural forms of the valve body in stop valves include straight-through type, straight-flow type, and right-angled type. The straight-through type is a common design, but it has high fluid resistance ； DC types have lower fluid resistance and are often used for fluids containing solid particles or those with high viscosity. Right-angled valve bodies are often forged and are suitable for globe valves with smaller diameters and higher pressures. Installation and maintenance of globe valves ① Globe valves operated by handwheels or handles can be installed at any position in the pipeline. ②Handwheels, handles, and transmission mechanisms shall not be used for lifting. ③During installation, care should be taken to ensure that the flow direction of the medium is consistent with the direction of the arrows indicated on the valve body. ④Globe valves equipped with drive mechanisms (such as gear-driven, electric, pneumatic, or hydraulic types) shall be installed in accordance with the provisions of the product’s instruction manual.