Functional Safety - Compliance with 61508 and 61511

Functional Safety – Compliance with 61508 and 61511

The HSE recognises BS EN 61508, and its associated daughter standards (e.g. BS EN 61511,BS EN 62061 etc.) as good practice in the implementation of safety systems. Incidents such as Buncefield, shown overleaf, have prompted much thought into how processes can be made safer, and BS EN 61511, the process sector application of 61508, provides a good lifecycle model on how to do this. Of course, any individual or organisation can implement the life-cycle activities, but will the resulting system be compliant?

Haden Freeman has competent and experienced engineers, who have developed functional safety management systems and perform functional safety life-cycle activities compliant with the standards.

Everything from the planning of functional safety, to analysing the potential hazards, allocating target Safety Integrity Levels (SILs), through to the installation and commissioning of the Safety Instrumented Systems (SISs), and verifying that the installed system meets the target SIL.

Experienced process engineers chair and document HAZOPs and HAZIDs, and undertake SIL determination for hazard mitigation Safety Instrumented Functions (SIFs). This provides the basis for the E&I engineers to specify the trips required to carry out the safety function.

The logic solver, be it relay based or Safety PLC, is specified and designed in-house, where software factory testing can take place.

Once on site, our experienced commissioning team ensures that the installation meets the design requirements, that the trip actions operate correctly and confirm that the target SIL has been achieved for the installed system.

Haden Freeman can develop periodic test procedures for clients to maintain the SIS and, if requested can carry out these tests on that basis.