Should the valve body of a quick-opening valve be a ball valve or a gate valve?
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Should the valve body of a quick-opening valve be a ball valve or a gate valve? The pneumatic on-off valves encountered in daily work all have ball valve bodies; I wonder why gate valve bodies aren’t used? Globe valves are generally cheaper than ball valves. I guess that’s the case, right? A ball valve can be quickly opened with only a small amount of torque, while does a gate valve require a greater opening torque? Is that why the cylinders chosen are more expensive than ball valves? So, why choose a pneumatic ball valve? Faster action time? So, what are the advantages and disadvantages of the two in terms of sealing performance?
Butterfly valves and gate valves have different structures. Pneumatic valves can use gate valve bodies.
Generally, the time required to rotate 90 degrees is shorter than that for gate valves. The ball valve has two sealing seats.
Gate valves don’t open quickly; they’re extremely slow
A ball valve operates with partial rotation – the valve stem rotates 90° to move the closing element (the ball) back and forth. A gate valve, on the other hand, requires full rotation; turning the handwheel causes the valve stem to move up and down, thereby moving the closing element (the gate) back and forth. In simple terms, for a ball valve, one complete opening and closing cycle is achieved when the valve stem rotates 90° (as it is designed to rotate only that much), while for a gate valve, the valve stem needs to rotate 360×N° (where N is a large number) in order to fully open or close the valve
Actuators with linear travel are more than twice as expensive as those with angular travel, while the valve body of gate valves is not much cheaper.
The travel time meets the requirements for fast opening and closing.
I don’t know much about prices; if the cost of direct flow is really that much higher, then it’s indeed more appropriate to use ball valves rather than gate valves.
Do the two options use different types of actuators in terms of structure? Is it true, as mentioned below, that linear actuators are much more expensive and slower in operation, which is why ball valves were ultimately chosen?
This post was last edited by Zhou Liuliuxu on 2019-11-12 at 14:04. I’m not familiar with the prices of actuators, but linear-type valves aren’t necessarily slower in speed. In my previous work in the chemical industry, I saw gate valves and globe valves with a diameter of around DN350 being used as emergency shut-off valves; they had both manual and pneumatic operation options. The pneumatic version allowed for very fast opening and closing – it took less than ten seconds to fully open or close them. When operated pneumatically, the entire pipeline would vibrate somewhat loudly. On the other hand, when large-diameter multi-turn valves are operated manually, it can be a real pain to open them