Can a control valve be used as an SIS emergency shut-off device?
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According to the specifications, the solenoid valve attached to the control valve should be installed between the valve positioner and the actuator. Can control valves be used for emergency shutdown?
From a safety perspective, control valves should not be used for emergency shutdown; emergency shut-off valves generally require higher performance standards in terms of response time and leakage prevention.
Except for special purposes, control valves are generally not used as shut-off valves
Look at the SIL level; the specifications for safety instrumented systems in the petrochemical industry specify which levels are permissible and which are not
No, they are not at the same level. The safety review won’t pass
According to the specifications, the solenoid valve is installed between the positioner and the actuator, and that is what people do these days as well. In domestic design at the end of the last century, regulating valves combined with solenoid valves were used as interlock valves; however, after interlocking, operators were generally required to close the upstream and downstream manual valves to ensure no leakage. Later on, they gradually stopped doing it. From your previous posts, it seems that you are upgrading the tank area and installing an SIS system to meet safety regulations. Therefore, the original control valve certainly does not have a SIL certification, and from a regulatory perspective it does not meet the requirements. Of course, you can consult safety experts to see if it is possible to meet these requirements. Current designs often use pneumatic ball valves as emergency shut-off valves.
Today, pneumatic ball valves are mostly used as emergency shut-off valves; control valves should not be used as such. Safety inspections are quite strict in the tank farm area.
It is possible; by modifying the air circuit and using solenoid valves to control the quick-release valve, emergency shutdown can be achieved. This approach is widely used in many devices.
It’s better to be proper; I agree with what was said on floor 5.
It is best to use an emergency shut-off valve; if modification is required based on the existing setup, a control valve can also be used
The SIS system must not be used at all; its security level is definitely not sufficient； Emergency shutdowns where the security requirements for DCS systems are not high can be implemented in this way. However, the leakage level of the control valve must meet the specified standards, and its switching time must be within the required range (this is achieved through the use of solenoid valves, air-controlled valves, etc.).