Which is better, an ASME ball valve or a gate valve?
The main differences between ball valves and gate valves lie in their valve core, seat, stroke, actuator, media flow direction, and maintenance. Generally speaking, when choosing between installing a gate valve or a ball valve before and after a control valve, if economy is a primary consideration, use a gate valve, as it is much cheaper. Gate valves are also suitable for large-diameter, low-pressure oil, hơi nước, and water pipelines. If sealing is a priority, use a ball valve. Ball valves are suitable for applications with high leakage requirements, are suitable for rapid opening and closing, and have a longer lifespan than gate valves.
Which is better, a ball valve or a gate valve?
Since both gate valves and ball valves can be used after control valves and perform similar functions, differing only in structure, users often wonder whether to choose a gate valve or a ball valve. This article will discuss this point. Before delving into the question, we must first clarify that there is no inherently better product than a gate valve or ball valve for installing before or after a control valve. The choice depends on the user’s specific circumstances and operating conditions. Let’s first briefly understand the characteristics of gate valves and ball valves.
Functionally, gate valves can be installed before and after control valves, primarily used in water supply and hot water pipelines, commonly known as water valves. They are generally not used in steam pipelines because the gate is difficult to open under high steam pressure. They are also unsuitable for pipelines with sediment, as sediment accumulation in the gate’s seat groove can cause incomplete closure. The gate valve’s opening and closing element is a gate, whose movement is perpendicular to the fluid direction. Gate valves can only be fully open or fully closed; they cannot be used for regulation or throttling. Ball valves can also be installed before and after control valves. In pipelines, they are mainly used for shut-off, distribution, and changing the flow direction of the medium. They have the same 90-degree rotation action, but the difference is that the plug body is a ball with a circular through-hole or channel along its axis.
From an advantage perspective, gate valves are characterized by low resistance, short size, and low price. The relative advantage of ball valves is their superior fluid control characteristics. They only require a 90-degree rotation and a small torque to achieve a tight seal. Ball valves are best suited for on/off and shut-off applications.
From the above, we can see that both gate valves and ball valves can be used before and after control valves. Neither valve is ideal for flow control, although ball valves offer better fluid control characteristics and sealing performance. However, in actual installation cases, although both gate valves and ball valves are used before and after control valves, gate valves are more frequently chosen by users. Why is this? Specifically:
1. Ball valves are more cumbersome to operate and require high-quality sealing surfaces. Ball valves require strict manufacturing processes for sealing; choosing the wrong manufacturer can easily lead to internal leakage due to insufficient technical expertise. This also results in relatively high costs, especially for large-diameter ball valves. Gate valves, on the other hand, have lower purchase costs, better sealing performance, require less effort to operate, and provide maximum flow path without resistance when fully open.
2. Ball valves may jam after a period of inactivity.
3. Ball valves have stricter requirements for the medium compared to gate valves. For example, they are only suitable for media containing high levels of fiber or oxygen.
