The core difference between ball valves and gate valves

1. Structure and Opening/Closing Method: The ball valve achieves on-off operation by rotating the spherical valve core by 90 degrees. The valve core is a spherical body with a through-hole, featuring a small rotation angle and fast movement. The gate valve, on the other hand, operates by the valve disc moving up and down along the axis of the valve seat. It requires multiple rotations during opening and closing, resulting in a longer movement stroke and much slower speed. 

2. Flow passage and flow capacity: The internal flow passage of the ball valve is straight and has minimal resistance, resulting in almost no pressure drop when the medium flows through. The diameter of the flow passage is basically the same as that of the pipeline, making it highly suitable for high-flow scenarios; in contrast, the flow passage of the gate valve is bent, causing the medium's flow path to change direction, resulting in high resistance. Under the same diameter, the flow capacity of the gate valve is much lower than that of the ball valve. 

3. Sealing and Applicable Pressure: The ball valve achieves sealing through the contact between the spherical surface and the valve seat. It has excellent sealing performance and can only be used for cutting off. Most conventional ball valves cannot precisely regulate the flow rate and are only suitable for full opening and full closing. The valve disc of the globe valve can stop at any position, allowing for precise control of the medium flow rate and pressure. The adjustment capability is its core advantage. In high-pressure conditions, the sealing and pressure-bearing performance are also more stable. 

4. Installation and Flow Direction: Ball valves generally have no restrictions on flow direction. They can be installed either in the forward or reverse direction, and the installation process is simple. Gate valves have specific requirements for the flow direction of the medium. The valve body will have an arrow indicating the direction, and they must be installed in accordance with the direction. Installing them in the reverse position will significantly affect the performance and sealing of the valve. 

5. Application scenarios and service life: Ball valves operate smoothly and with minimal wear, making them suitable for frequent opening and closing in pipelines. They are commonly used in water supply and drainage, gas, and general fluid transportation. Globe valves focus on throttling, pressure regulation, and shut-off, and are mostly used in steam, oil products, chemical media, and industrial pipelines requiring precise flow control. They are not suitable for frequent opening and closing and have a more reliable service life under long-term throttling conditions. 

6. In terms of price and maintenance: For the same specifications, ball valves have a simpler structure, lower cost, and easier daily maintenance; while gate valves have more complex components, higher costs, and require more steps for repair and disassembly.