SIL, or Safety Integrity Level, is a measure of the functional safety of an electrical, electronic, or programmable safety-related system. Defined within the international IEC 61508 standard, there are four SIL levels, each corresponding to a progressively lower probability of failure on demand.
In rotating machinery applications, different protection functions require different SIL levels. While shaft overspeed and thrust or axial position protection frequently require SIL 3 certification—and Sensonics solutions can be certified to meet these requirements—vibration protection functions are more commonly specified at SIL 2 or SIL 1, depending on the application and risk assessment.
A SIL-certified safety solution signifies a system with a proven level of reliability and accuracy in detecting and mitigating hazardous conditions, providing essential assurance for turbines and rotating plant.
How do SIL-3 certified systems help maintain the operational integrity of rotating plant?
1. Safe and reliable shutdown mechanisms
Turbines and rotating equipment are particularly vulnerable to overspeed, excessive axial movement, and damaging vibration levels, all of which can lead to catastrophic failure if left unchecked.
At Sensonics, our SIL-certified systems support certified shutdown functions that activate immediately when predefined conditions are exceeded—for example, when a safe speed threshold is breached. Where required, these shutdown functions can be designed and certified to SIL 3, particularly for overspeed or thrust protection, ensuring operations are halted before a hazardous situation develops. This protects equipment, personnel, and surrounding infrastructure.
2. Compliance with IEC 61508 standards
Compliance with IEC 61508 is widely recognised as a benchmark of quality and operational excellence in safety system design. Sensonics’ SIL-certified solutions are developed in accordance with these standards, ensuring that protective functions are implemented with proven reliability, systematic fault avoidance, and built-in fail-safe principles.
This structured approach provides operators and stakeholders with confidence that each protection function meets its appropriate SIL requirement, rather than applying a one-size-fits-all certification level.
3. Proof testing for improved reliability
Proof testing is a fundamental requirement of SIL-certified systems, regardless of the SIL level achieved. Its purpose is to identify hidden or dormant failures that may not be apparent during normal operation. By simulating fault conditions or isolating and testing specific components, proof testing validates that the system continues to meet its required safety performance level over time, in line with IEC 61508 targets. Sensonics systems are designed to support effective and practical proof testing, using extensive field experience and industry benchmarks to ensure long-term dependability across speed, position, and vibration protection functions.
4. Risk mitigation for safety-critical applications
Rotating machinery used on offshore platforms, in petrochemical facilities, power plants, and other high-risk environments is often classed as safety critical. These applications demand a rigorous and proportionate approach to risk mitigation.
Our SIL-certified solutions help bridge the gap between condition monitoring and active machinery protection. By integrating speed, position, and vibration monitoring within a single architecture—each engineered to the SIL level appropriate to its function—operators can manage risk holistically and respond rapidly to developing faults.
Protecting the present, engineering the future
SIL certified systems are the global benchmark in safety for rotating machinery. With nearly 50 years’ experience at the forefront of the vibration, position, and machinery protection technology sector, Sensonics solutions combine advanced monitoring with proven safety mechanisms. To find out more about how our products meet the requirements of your application, please get in touch today by clicking here.
