Engineering English
Safety Instrumented System
Chemical Engineering · Engineering Safety · Last updated: July 30, 2026 · How this entry was written
Definition: A safety instrumented system is a layer of protection designed to prevent hazardous events by detecting abnormal conditions and taking automated actions. It is composed of sensors, logic solvers, and final control elements to achieve a safety function.
Example in context
“The safety instrumented system was tested during the plant shutdown to ensure it would trip the reactor in case of overpressure.”
“Güvenlik enstrümante sistemi, aşırı basınç durumunda reaktörü kapatacağından emin olmak için tesis kapatma sırasında test edildi.”
Where engineers use it
Safety instrumented systems are applied in refineries and chemical plants to detect dangerous deviations and automatically activate shutdown valves or other safety actions. An engineer must design, verify, and maintain SIS to meet safety integrity level (SIL) requirements and comply with standards like IEC 61511.
Synonyms: SIS, safety shutdown system, emergency shutdown system
In Engineering Safety
An arrangement of sensors, logic solver and final elements that is independent of the basic control system and acts to bring a process to a safe state when defined limits are exceeded. Its performance is specified in terms of integrity levels.
“The safety instrumented system trips the feed pump and closes the inlet valve whenever two of three pressure transmitters exceed the high-high set point.”
Practice: can you use “Safety Instrumented System” at work?
During a plant turnaround, you are asked to review the SIS logic solver configuration for a high-pressure reactor. Justify the need for a separate logic solver compared to the basic process control system.
Show a model answer
“The safety instrumented system must be tested periodically to maintain its integrity.”
“Safety Instrumented System” in 21 languages
| English | Safety Instrumented System |
|---|---|
| Turkish | güvenlik enstrümante sistemi |
| French | système instrumenté de sécurité |
| German | sicherheitsinstrumentiertes System |
| Spanish | sistema instrumentado de seguridad |
| Chinese | 安全仪表系统 |
| Arabic | نظام الأمان الآلي |
| Portuguese | sistema instrumentado de segurança |
| Russian | система безопасности на основе приборов |
| Japanese | 安全計装システム |
| Italian | sistema strumentato di sicurezza |
| Vietnamese | hệ thống thiết bị an toàn |
| Hindi | सुरक्षा इंस्ट्रुमेंटेड प्रणाली |
| Thai | ระบบเครื่องมือวัดเพื่อความปลอดภัย |
| Indonesian | sistem instrumentasi keselamatan |
| Korean | 안전 계장 시스템 |
| Bengali | নিরাপত্তা উপকরণ ব্যবস্থা |
| Dutch | beveiligingsinstrumentatiesysteem |
| Swedish | säkerhetsinstrumenterat system |
| Finnish | turvallisuusinstrumentoitu järjestelmä |
| Ukrainian | система безпеки на основі приладів |
Frequently asked questions
What does Safety Instrumented System mean in engineering?
A safety instrumented system is a layer of protection designed to prevent hazardous events by detecting abnormal conditions and taking automated actions. It is composed of sensors, logic solvers, and final control elements to achieve a safety function. In Chemical Engineering, the term carries a usage-frequency rating of 10/10 in the Engineering English library.
How do you pronounce Safety Instrumented System?
Safety Instrumented System is pronounced /ˈseɪfti ˈɪnstrəmɛntɪd ˈsɪstəm/ (IPA). The Engineering English app plays audio for the term and checks your pronunciation with speech recognition.
How is Safety Instrumented System used in a sentence?
Example from an engineering context: “The safety instrumented system was tested during the plant shutdown to ensure it would trip the reactor in case of overpressure.”
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