Safety Instrumented Systems according NEN-EN-IEC 61508 /61511

Safety Instrumented Systems (SIS) are applied for safety, but also to protect the environment or to prevent equipment damage and loss. IEC 61508/61511 are international standards, giving requirements to SIS systems based on the SIL concept. The SIL concept is increasingly used worldwide.

Some relevant aspects:
• SIL – Based on the risk level;
• Compliance with technical requirements - SIL classes, principles for design;
• Creation of a Safety Management System - Activities, planning, responsibilities, procedures;
• Focus on safety life cycle - from basic engineering, operation until decommisioning;
• Documentation and verification - Capture and control of information;
• Functional requirements - Use of overrides, start-up procedure, the dynamic process;
• Periodic activities - testing, maintenance, assessments, implement improvements.

Comply with the IEC requirements
A Safety Instrumented System (SIS) is more than a technical device acting when a process deviates  too much. Research has show that many accidents happen because of the human factor problem: poor specification of the SIS and carelessly implemented modifications.  Work should be subject to a quality system and proper procedures. During the engineering phase but also during the operational phase.

SSC has TÜV certificate "Functional Safety - Safety Instrumented System.

SIL schema ib

Picture above: Safety systems (SIS) should always be separate from the control.

Only 44% of Major Hazards companies apply SIL !

Column November 2010
Only 44% of Major Hazards companies apply SIL !

The Dutch Labor Inspectorate performed an inspection of 58 Major Hazards companies . This was a follow up of the BP Texas City disaster. Recently, a report with the inspection results have been p...

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