Regarding a valve status
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Does FL stand for accident lockout, meaning that the valve remains in its original position in the event of a gauge air failure? Please advise
FL stands for fault hold, which means that the valve remains in its original position in the event of a fault
What was said on the second floor is correct; the three-stage protection of the valve is used for position maintenance. Please give some guidance below
In practice, it is still divided into two categories, depending mainly on the original intention of the design team; generally, they are categorized as air supply failures and power supply failures.
You shouldn’t try to understand this thing in too complex a way, because it is primarily the manufacturing processes that set the requirements, and then our instruments are used to implement them!
If there is only FL, it is generally a loss of air lock. If it is FLC(O), L stands for loss of air, and C stands for loss of power.
Just as there is a feature in control systems known as power loss retention during configuration, such systems ensure that the values displayed after a power loss remain unchanged at the level they were on just before the power loss occurred. Similarly, if valves need this functionality – that is, in the event of a sudden gas supply interruption or power outage – the valve should remain in the position it was in immediately before the change in power source. This can be achieved through air storage tanks or energy storage devices, or via mechanical locking mechanisms.
By \"loss of air lock,\" do you mean that the valve remains in its original position after a fault in the instrument air?
There are three types of fault locations: power loss, air loss, and signal loss. The specific requirements depend on those specified in the process. FL stands for fault retention, but as for what exactly constitutes a fault, it depends on the process requirements – whether it is power loss, air loss, or signal loss.
Three-stage protection for power failures actually has both advantages and disadvantages. Three-stage protection for power failures actually has both advantages and disadvantages.