Is there interlocking in the SIS system?
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I have a question for everyone: Is there any interlock mechanism in the SIS system? If so, how is it implemented?
How should interlocking be understood? It’s self-locking, right? After each logical trigger, if the logic isn’t reset, it can’t return to its initial state.
What I want to express is that there are two pipelines leading into the same tank, and each of these pipelines is equipped with a shut-off valve; what type of interlock is needed to ensure that these two shut-off valves cannot be opened simultaneously? What’s its name? That is, when one of the cut-off valves is opened, the other one is closed – how is this logic implemented?
There are many ways to achieve this; what needs to be known is whether both valves are involved in the interlock or just one of them. What are the conditions for participating in interlocking? It’s necessary to explain them generally in order to understand how to implement it.
It’s only the interlock between these two valves that comes into play; the others are not involved. When one valve is opened, the other valve is in a closed state
Assume the two valves are: A, B. When valve A is opened, its open state is used as the interlock condition, while a closed valve B triggers the interlock action. Conversely, when valve B is opened, its open state is used as the interlock condition, with valve A being closed to trigger the interlock action.
So, it’s necessary to choose a three-way on/off valve with two inlets and one outlet, to ensure that only one feed path is open at a time.
Thank you very much; the approach you suggested is also a solution
What are the interlock conditions? How many?
The SIS system determines how the actuator should operate, based on the logical relationships in emergency situations. It cannot be simply described as interlocking or interconnection.