Several issues with safety instrumented systems
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Recently, there have been demands that the chemical industry start to implement safety instrument systems in high-risk positions gradually, but we know very little about this. Therefore, we would like to ask our seniors and experts: 1. What constitutes a complete safety instrument system? In addition to the systems and on-site instruments needing to meet the corresponding SIL levels, are there any similar requirements for the wiring and external power supplies? 2. Is there any difference in the installation of safety instruments compared to ordinary instruments? 3. Which instruments at home and abroad have SIL certification? Temperature, pressure, and solenoid valves generally have it; do motor protectors and AC electrical contactors also have SIL certification? 4. Must the safety instrument system be certified by a relevant authority? Is it acceptable to operate without such certification? Could everyone in the system help answer this? Thank you. If there are anyone who makes instruments for this purpose, you can also leave me a message
Generally, SIS systems are required to undergo certification; it’s difficult to achieve full certification for field instruments. China’s economic conditions are also quite complex. At present, as long as it can be seen that a SIS system is in use, no further action is taken – basically, no one goes to the site to conduct inspections. :lol
The indoor components of standard SIS systems are generally SIL-certified, with many brands available such as Conixen, Heima, ICS, SM, and so on. Basically, Sil3 is fine; those that aren’t certified definitely won’t work, as it’s a mandatory requirement. But it’s not possible outdoors; in other words, it can only achieve independence from the DCS system. However, it is impossible to achieve the detection of the original device, the honor of the actuator, or triple redundancy, as the cost is extremely high. I suddenly realized there’s so, so much I need to say………………