SGS-TUV Saar Functional Safety Certificate (SIL) for Automatic Valves Pneumatic Products

About SGS-TUV Saar GmbH

SGS-TUV Saar GmbH is a joint venture between SGS SA (the world's leading testing, inspection, and certification company) and TUV Saarland (a respected German technical inspection organization). The organization is accredited to perform functional safety assessments and certifications under IEC 61508 and related sector-specific standards. Their functional safety assessments are recognized worldwide and are accepted by regulatory authorities, safety consultants, and end users across the process industries, machinery sector, and other safety-critical applications.

Certification Scope and Product Coverage

The SGS-TUV Saar Functional Safety Certificate for Automatic Valves covers NAMUR Series pneumatic solenoid valves, including general purpose, explosion-proof, and intrinsically safe configurations. According to the certificate, these products are certified for Safety Integrity Level 2 (SIL 2) in singular (single-channel) application with a Hardware Fault Tolerance (HFT) of 0, and for Safety Integrity Level 3 (SIL 3) with Performance Level e (PL e) in redundant application with a Hardware Fault Tolerance (HFT) of 1 or greater. This dual rating provides safety engineers with the flexibility to use Automatic Valves products in a wide range of safety-critical architectures.

Understanding Safety Integrity Levels (SIL) and IEC 61508

The IEC 61508 standard, titled "Functional Safety of Electrical/Electronic/Programmable Electronic Safety-Related Systems," is the foundational international standard for functional safety. It provides a comprehensive framework for managing functional safety throughout the entire lifecycle of a safety-related system, from concept and design through installation, operation, maintenance, and decommissioning. The standard defines four Safety Integrity Levels (SIL 1 through SIL 4), with SIL 4 representing the highest level of safety performance and SIL 1 the lowest.

SIL Ratings Explained

Each Safety Integrity Level corresponds to a range of target failure probabilities for the safety function. For low-demand mode applications (where the safety function is called upon to operate less than once per year), SIL 1 requires a Probability of Failure on Demand (PFD) between 0.1 and 0.01, SIL 2 requires a PFD between 0.01 and 0.001, SIL 3 requires a PFD between 0.001 and 0.0001, and SIL 4 requires a PFD between 0.0001 and 0.00001. These progressively tighter requirements mean that higher SIL ratings demand exponentially more reliable components and system architectures. The Automatic Valves SIL certification to SIL 2 in single-channel and SIL 3 in redundant configurations places these products among the most safety-reliable pneumatic valves available on the market.

Hardware Fault Tolerance (HFT)

Hardware Fault Tolerance is a key concept in functional safety that describes the ability of a system to continue performing its safety function even when one or more hardware components have failed. An HFT of 0 means the system has no fault tolerance and a single hardware failure could prevent the safety function from operating. An HFT of 1 means the system can tolerate one hardware failure and still perform its safety function. Achieving SIL 3 with HFT of 1 or greater, as certified for Automatic Valves products in redundant configurations, means that a redundant pair of these valves provides an extremely high level of safety reliability, suitable for the most demanding safety applications in the process industries.

Relationship to IEC 61511 and Process Safety

While IEC 61508 is the generic functional safety standard, the process industries typically apply IEC 61511 (titled "Functional Safety - Safety Instrumented Systems for the Process Industry Sector") as the sector-specific implementation. IEC 61511 references IEC 61508 for the certification requirements of individual safety components, meaning that a pneumatic valve certified to IEC 61508 by SGS-TUV Saar can be directly specified in Safety Instrumented Systems (SIS) designed according to IEC 61511. This makes the Automatic Valves SIL-certified products directly applicable to safety systems in oil and gas, chemical, pharmaceutical, and other process industry facilities.

SIL-Certified Automatic Valves Products

Automatic Valves, a brand of ROSS Controls headquartered in Ferndale, Michigan, has been manufacturing pneumatic valves for industrial automation since 1945. The company's commitment to quality and safety is demonstrated by its investment in achieving SIL certification from SGS-TUV Saar, one of the most demanding and respected functional safety certification bodies in the world.

The SIL-certified product range includes the NAMUR Series of solenoid-operated pneumatic valves, which are specifically designed for direct mounting on quarter-turn and linear actuators according to the NAMUR (VDI/VDE 3845) interface standard. These valves are used extensively in process control applications for emergency shutdown, safety interlock, and critical process control functions.

Key Technical Specifications

The SIL-certified NAMUR Series valves feature spool-type construction with bar stock aluminum valve bodies and aluminum spools, Buna-N (nitrile) seals, Polyamid 66 solenoid bodies, and solenoid pilot-controlled actuation. Available in 3/2 normally closed, 5/2, and 5/3 (closed center, open center, and power center) configurations, these valves cover all common actuator control requirements. Operating pressure ranges from 0 to 150 psig for 3/2 valves, 35 to 150 psig for 5/2 valves, and 50 to 150 psig for 5/3 valves. The operating temperature range extends from -29°C to 50°C (-20°F to 123°F), making these valves suitable for both indoor and outdoor installations in a wide range of climatic conditions.

Safety Data and Reliability Parameters

The SIL certificate from SGS-TUV Saar includes specific reliability data that safety engineers need to calculate the overall Safety Integrity Level of their Safety Instrumented Functions (SIF). This data typically includes the dangerous failure rate, safe failure fraction, mean time to dangerous failure (MTTFd), and diagnostic coverage factor. These parameters are essential inputs for Safety Integrity Level verification calculations performed according to IEC 61508 or IEC 61511 methodologies. The certificate confirms that Automatic Valves NAMUR products achieve SIL 2 capability in singular application (HFT = 0) and SIL 3 capability in redundant application (HFT greater than or equal to 1), providing safety engineers with verified data they can confidently use in their SIS design calculations.

Applications for SIL-Certified Pneumatic Valves

SIL-certified pneumatic valves from Automatic Valves are deployed in a wide range of safety-critical applications across the process industries and beyond. Any application where the failure of a valve to operate on demand could result in a hazardous event is a candidate for SIL-rated valve components.

Common applications include Emergency Shutdown (ESD) systems where valves must close (or open) rapidly to bring a process to a safe state, fire and gas safety systems where valves control suppression media or isolation barriers, burner management systems in boilers and furnaces where valve failure could lead to explosive fuel accumulation, critical process isolation where valves provide last-resort containment of hazardous materials, and turbine and compressor protection systems where rapid valve action prevents mechanical damage or hazardous releases.

In all of these applications, the SIL certification from SGS-TUV Saar provides the documented evidence that safety regulators, insurance companies, and corporate safety teams require to approve the use of Automatic Valves products in their safety-critical installations.

Download the SGS-TUV Saar SIL Certificate

The complete SGS-TUV Saar Functional Safety Certificate for Automatic Valves NAMUR Series pneumatic valves is available for download in PDF format from this page. This document provides the specific SIL ratings, hardware fault tolerance values, and applicable standard references that safety engineers need for their Safety Instrumented System design and verification calculations.

Automatic Valves, part of the ROSS Controls global family, is exclusively focused on fluid power, delivering high-quality and cost-effective pneumatic solutions for safety-critical applications in the automation, transportation, process, and automotive industries. For technical support or assistance with SIL-rated valve selection, contact Automatic Valves Technical Service through their website at www.automaticvalve.com.

Frequently Asked Questions

What is a SIL certificate and why does it matter?

A SIL (Safety Integrity Level) certificate is a third-party document verifying that a product meets the functional safety requirements of IEC 61508 for use in safety-related control systems. It matters because it provides quantitative reliability data and design assurance that safety engineers need to include the product in Safety Instrumented Systems (SIS) that protect people, the environment, and assets from hazardous events. Without SIL certification, a valve cannot be confidently specified for safety-critical applications.

What SIL rating do Automatic Valves products achieve?

Automatic Valves NAMUR Series pneumatic valves are certified by SGS-TUV Saar for SIL 2 in singular (single-channel) application with Hardware Fault Tolerance (HFT) of 0, and for SIL 3 with Performance Level e in redundant application with HFT of 1 or greater. This means a single valve can be used in SIL 2 applications, while a redundant pair of valves can achieve SIL 3 safety performance.

What is the difference between SIL 2 and SIL 3?

SIL 2 requires a Probability of Failure on Demand (PFD) between 0.01 and 0.001, meaning the safety function will fail to operate on demand no more than once in 100 to 1,000 demands. SIL 3 requires a PFD between 0.001 and 0.0001, meaning no more than one failure in 1,000 to 10,000 demands. SIL 3 represents a significantly higher level of safety reliability and is typically required for the most critical safety functions in process plants.

Who is SGS-TUV Saar and why is their certification important?

SGS-TUV Saar GmbH is a joint venture between SGS SA and TUV Saarland, specializing in functional safety certification. They are one of the most respected and globally recognized certification bodies for IEC 61508 functional safety assessments. Their certification is accepted by safety regulators, end users, and engineering consultants worldwide, providing strong assurance that certified products meet rigorous functional safety requirements.

Can I use Automatic Valves SIL-certified products in IEC 61511 safety systems?

Yes. IEC 61511, the process industry sector-specific standard for Safety Instrumented Systems, references IEC 61508 for the certification of individual safety components. Pneumatic valves certified to IEC 61508 by SGS-TUV Saar, such as the Automatic Valves NAMUR Series, can be directly specified in SIS architectures designed according to IEC 61511. The reliability data provided in the SIL certificate is used as input for the SIL verification calculations required by the standard.