SIS shut-off valve
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I’m seeking advice from experts: is it possible to manually open or close this isolation valve (which is connected to the SIS system)? What should be done?
1. Why do you want to manually intervene to turn it on/off? 2. The isolation valves that are part of the SIS interlock system are installed as safeguards to prevent serious safety and property accidents; modifying them without permission – do you really want to end up in prison? 3. To put it another way, an emergency shut-off button can be added to the auxiliary control panel; if you press that button, it could trigger corresponding interlocks, resulting in casualties or the shutdown of the equipment – will you be responsible for that? When starting it, a reset is required – do you want to press the reset button to open the valve before all the alarms or safety measures have been disabled?
Sil1 works fine; logical priority can be used, or dual solenoids can be installed. Sil2 doesn’t work
Many SIS interlocks are equipped with manual buttons to facilitate manual intervention in emergency situations, just as high-speed trains and subways have manual stop buttons
Sure, that’s fine, but are you sure you want to do this? Just remove the interlock. But one has to take responsibility if something goes wrong; if it involves modifying the interlock logic, it’s better to let the process team come up with a solution.
Disable the SIS interlock and force the valve. I suggest you consider the consequences; we must not operate the process valves on our instruments carelessly.
Consider the consequences! This allows for the interlock to be disabled, after which operations can be carried out from the auxiliary control panel!
Once in the SIS system, manual switching should be avoided; at most, a manual interlock can be used, but such an interlock must be equipped with a reset confirmation button. If manual operation of the valves is necessary, a thorough SIL rating assessment must be carried out. Your company can proceed with this approach only if it can afford the safety hazards that may result from interlock failures caused by human error; having an emergency plan in place is essential.
Once in the SIS system, manual switching should be avoided; at most, a manual interlock can be used, but such an interlock must be equipped with a reset confirmation button. If manual operation of the valves is necessary, a thorough SIL rating assessment must be carried out. Your company can proceed with this approach only if it can afford the safety hazards that may result from interlock failures caused by human error; having an emergency plan in place is essential.
Once in the SIS system, manual switching should be avoided; at most, a manual interlock can be used, but such an interlock must be equipped with a reset confirmation button. If manual operation of the valves is necessary, a thorough SIL rating assessment must be carried out. Your company can proceed with this approach only if it can afford the safety hazards that may result from interlock failures caused by human error; having an emergency plan in place is essential.
It’s very simple to do; once the process has undergone change confirmation, just add a soft button and use an AND function block or an RS flip-flop to determine the priority