What does the flow action of a control valve mean?
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In the specification sheet for control valves, there is an item under the valve body section titled “Flow action to: open”. What does this mean? What is often seen is open.
Why is it FC upstairs? It’s clearly open
It should mean “flow away,” that is, the direction in which the fluid acts on the valve core
I agree that the term \"flow action to open\" on the fourth floor is easy to understand – it simply refers to the flow of fluid. This has nothing to do with FC or FO; it describes the direction of flow through the valve body. The F in FC and FO likely stands for failure to close/open
I’ve encountered the same problem: “Flow action to : 160mm” – I don’t know what that means either
The fourth floor is the correct answer; 160mm was entered incorrectly – it’s hard to understand
Take action to open it – there’s no problem with that. 160mm is likely the maximum travel of the valve (fully open)
. . . . Is there also the concept of flow shutdown for control valves? That’s strange – don’t control valves have a direction? Flow always occurs from bottom to top, that is, in one direction; so isn’t it meaningless to write it that way?
While paying attention to this issue, I encountered this as well, but I didn’t take it seriously and decided to learn* learn*.
Regulating valves come in two types: flow-open and flow-closed. In the flow-open type, the force exerted by the fluid on the valve core is in a direction that causes the valve core to open； Flow closure occurs when the force exerted by the fluid on the valve core is in the direction that causes the valve core to close. The choice between flow-on and flow-off mode is determined during the selection and design phase of the control valve; it should be installed in accordance with the design specifications, otherwise the control valve may not function properly.