Comprender las diferencias entre la válvula de escalón y la válvula de compuerta

 
As essential industrial valves in pipeline systems, both globe valves and gate valves play indispensable roles in areas such as pipeline transportation and industrial production. Despite their similarities in appearance, structure, and function, there are significant differences in detail that directly impact applications and performance of these industrial valves.
   
Firstly, structurally, a gate valve tightly closes its sealing surface against the pressure of the medium, preventing leakage. During the opening and closing process, the gate valve's gate and seat sealing surfaces always remain in contact and rub against each other, making the sealing surface prone to wear. In contrast, a globe valve has a relatively simple structure, with the sealing surface being a small trapezoidal side of the valve stem; even if the valve core falls off, it is equivalent to the valve being closed. Additionally, in terms of appearance, for the same diameter, gate valves are generally taller than globe valves, while globe valves are longer. Gate valves are also divided into rising stem and non-rising stem types, while globe valves do not have this distinction.
   
Secondly, in terms of operation principles, a globe valve adopts a rising stem design, where rotating the handwheel causes the stem to rise or fall, thereby opening or closing the valve. On the other hand, a gate valve operates by raising or lowering the stem through rotation of the handwheel, but the position of the handwheel itself remains unchanged. Furthermore, a globe valve can be used for both shut-off and flow regulation, while a gate valve can only be fully open or fully closed and cannot regulate flow. Globe valves have designated inlet and outlet directions, whereas gate valves do not have such requirements.
   
Moreover, concerning sealing performance, the sealing surface of a globe valve is relatively simple, and once the valve core falls off, it is equivalent to the valve being closed. Although the sealing effect may not be ideal under high pressure differentials, its check effect is better. In contrast, the sealing surface of a gate valve is achieved through the side of the gate, and its sealing effect is not as good as that of a globe valve; even if the valve core falls off, it will not close the valve like a globe valve.
   
Finally, in terms of performance, globe valves have greater fluid resistance and require more force during opening and closing. However, due to the short distance between the valve disc and the sealing surface, the opening and closing stroke is relatively short. Conversely, gate valves are easy to operate but have a longer opening and closing time because the gate and sealing surface are further apart. Additionally, when fully open, gate valves have almost zero fluid flow resistance within the valve body channel, making them very easy to operate.
 
In conclusion, understanding the characteristics and application scenarios of globe valves and gate valves is crucial to ensuring the correct selection and use of these valves, thereby meeting the needs of pipeline systems and maximizing efficiency and safety.