sil rating

Safe-T-Pull Device designed and manufactured at Safe-T-Products Malaga Western Australia
WHAT WE ARE DOING

SAFETY INTEGRITY LEVEL
(SIL) RATING

UNDERGOING COMPREHENSIVE TESTING AND ENSURING COMPLIANCE

Our devices are undergoing testing to meet the required standards for safety systems that demand a high level of reliability. These systems require a SIL rating, and the devices used in these systems must meet specific failure rate criteria as part of the overall SIL calculation.

To determine the failure rate, the device must undergo comprehensive testing to ensure compliance through a full Failure Modes and Effects Analysis (FMEA). Most devices on the market have not undergone actual testing but have been reviewed to state their compliance should they be subjected to testing. Safe-T-Products made the deliberate choice to follow a comprehensive independent testing regime to attain full compliance. While it may be a lengthy process, the benefits will far surpass the time and effort invested.
Obtaining SIL certification through real-life testing conducted by an independent certification authority will offer certainty and confidence in Safe-T-Products’ devices among safety-driven industries.

High Impact PC/PBT UV Stable Flame Retardant Plastic
Safe-T-Pull Device plastic pc/pbt designed and manufactured at Safe-T-Products Malaga Western Australia
2mm 316 Electro Polished Stainless Steel
Safe-T-Pull Device stainless steel designed and manufactured at Safe-T-Products Malaga Western Australia
3mm Powder Coated Aluminum
Safe-T-Pull Device Aluminium designed and manufactured at Safe-T-Products Malaga Western Australia

BENEFIT OF FULLY INDEPENDENT TESTING

  1. Independent Verification: Engaging third-party testing facilities for device durability assessments and partnering with functional safety auditing companies to conduct a comprehensive device FMEA offers an impartial and unbiased evaluation of the device’s safety and performance.
  2. Certification Authority: Securing a well-documented durability safety test certification that can be relied upon and will be recognised by relevant certification authorities and regulatory bodies is crucial for trust in the testing process.
  3. Safety Integrity Level (SIL): SIL serves as a measure for assessing the performance of safety systems employed across diverse industries. Having a fully endorsed performance level applicable to any SIL calculation ensures that Safe-T-Products’ devices are well-suited for a broad range of safety-critical applications.
  4. Real-Life Certification: The certification is not merely an assumption but a concrete, real-life documented safety test certification, offering tangible evidence of the devices’ safety and reliability.
  5. Industry Recognition: With the successful completion of rigorous independent testing, industries with stringent safety requirements, such as manufacturing, process control, and others, can have certainty and confidence in Safe-T-Products’ pull wire devices meeting their specific requirements.

Roadmap to Attain SIL rating

Safe-T-Products initiated its journey towards achieving SIL certification in mid-2015. While the process may have had earlier origins, a pivotal moment occurred in July 2015 when Cris Schulze, representing TUVRheinland Japan, presented an Advanced Seminar on the Functional Safety Standard ISO 13849 in our manufacturing facility in Malaga, Western Australia.
The strategic approach was structured as follows:
Clarify the definition of a single “operation.”
Develop an Automation Tester, known as STP-AMDT, capable of conducting the mechanical cycle durability test on three samples of our Safe-T-Pull pull wire devices. This test would subject each device to 6050 operations, record the applied Newton-meters
(Nm) of force and assess the device’s functionality post-endurance testing.
This plan was a significant step toward ensuring the certification of our products for SIL, with a particular emphasis on thorough testing and compliance with operational requirements and safety standards.

MILESTONES

Milestone – Testing of Electrical Component

(Completed)

SIL requires electrical components to comply with IEC 60947-5-1 compliant. Safe-T-Products worked with their supplier to design a microswitch with the stringent specifications required to pass the certification. The electrical durability tests to IEC 60947-5-1 for the safety direct-opening micro switch were successfully conducted by TUV Hungary on the Safe-T-Products special MVS 3400 and MVS 3600 Micro Switches.

Milestone – Safe-T-Pull Automation Mechanical Durability Tester (STP-AMDT) –

(CompleteD)

Develop bespoke SAFE-T-PULL Automation Mechanical Durability Tester (STP-AMDT)

Several of the durability tests specified in the standard were relatively straightforward to perform; However, finding an effective method for performing the 6050 full-cycle tests proved to be persistently challenging. From the outset, it became clear that the only way to successfully conduct the test was by creating a bespoke in-house automation tester specifically designed to suit our pull wire devices. This equipment was to mimic real-life field operations, accurately record the Nm force, and be strong enough to withhold prolonged testing.

After undergoing multiple changes to the initial design and programming over the past eight years, the Automation Tester was completed in mid-2023.

Milestone – Mechanical Cycle Durability Test –

(COMPLETED)

Safety in Mines Testing and Research Station (SIMTARS) in Queensland, Australia was willing to work with Safe-T-Products on the mechanical durability of the pull wire device. The Automation Tester was shipped to the facility, accompanied by technical staff and samples of the pull wire device.

  • 3 Sample of the STP in a PC/PBT Plastic enclosure
  • 3 Sample of the STP in an Aluminium enclosure
  • 3 Sample of the STP in a Stainless-Steel enclosure

Testing Procedure:

6050 full-cycle tests on 1 sample of each version sent, with each cycle consisting of five specific operations that must be executed in a particular sequence, while measuring the Nm of force and recording this data in a spreadsheet.

Operations:

  1. Left Pull Rod in
  2. Right Pull Rod in
  3. Left Pull Rod out
  4. Right Pull Rod out
  5. Reset

With a full-cycle time of 23 seconds, or roughly 156 per hour, it took three weeks to complete the testing of all three samples.

ENVIRONMENTAL DURABILITY TEST

(Completed)

Following the operation test, the next phase involves subjecting the same tested devices to extreme temperatures and humidity conditions as well as exposure to a saltwater solution. These conditions are intended to replicate a wide range of environmental situations.

Testing Procedure:

  • Testing at high temperature: 96 hours at +70 degrees C
  • Testing for variations in humidity and temperature: 96 hours in environment, changing between moist and warm atmosphere, at +25 degrees C
  • Testing at low temperature: 96 hours at -40 degrees C
  • Testing in a corrosive and salty environment: 96 hours at +35 degrees C in a solution of 5%NaCl

VIBRATION DURABILITY TESTING

(current stage)

After successful completion of the environmental durability test, the same devices proceed through additional tests designed to assess their continued mechanical durability.

Testing Procedure:

  • Shock Test: Evaluate the devices’ ability to withstand mechanical shocks
  • Vibration Test: Assess the devices’ resistance to vibration
  • Electrical Impulse Voltage Test at 2,500 V: Ensure electrical integrity under high voltage conditions
  • Resetting Test: Confirm that the devices can return to their proper state after activation or disruption
  • Wire Disengagement and Pull Wire Device Operation test: Verify that the devices continue to operate as intended after environmental and electrical durability testing

MILESTONES – failure mode & effects analysis (fmea)

IEC 61508 TYPICAL cERTIFICATE pROCESS

Safe-T-Products Malaga Western Australia SIL Rating IEC 61508 Typical Certificate Process