Regulator valve with cut-off function, SIS system problem
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Dear heroes, I would like to ask, there is a liquid level regulating valve that is adjusted in DCS. Now I want to add a cut-off function to the SIS system for interlocking. If it is equipped with a solenoid valve accessory with SIL level, can it be added to the SIS? SIL1 level
Strictly non-compliant, SIL1 requires the entire valve to have SIL1 rated functionality. However, many old equipment safety technical modifications use this method, and so-called experts have passed it.
There is no problem with SIL1. I have just communicated this matter with the design institute recently. There is no requirement in the standard to be independent.
Specification 7.2.1 SIL1 level safety instrumentation function, the control valve can be shared with the basic process control system, and the action priority of the safety instrumentation system should be ensured. Therefore, they can be shared, but the entire regulating valve and solenoid valve must be SIL certified products.
Can the cutting capacity of the regulating valve be achieved?
It should be ok. If you are not sure, ask someone to calculate the PFD of the circuit.