Functional Safety

Functional Safety – Compliance with 61508 and 61511

The incidents at Buncefield and BP Texas City Refinery in 2005 were a reminder that there was still a lot to learn even after the steps taken in the 15 years since the similar incident at Texaco’s Milford Haven Refinery. A move towards improved process safety saw the implementation of the Control of Major Accident Hazards Regulations 1999 (“COMAH”). The more recent BS EN 61508 and associated standards has moved the thinking on as to how to make processes safer.

Life-cycle activities can be easily implemented, but will the resulting system be compliant? Haden Freeman has put in a lot of resources to develop functional safety management systems to be capable of performing functional safety life-cycle activities compliant with the standards. HFL’s engineers are competent and highly experienced in implementing these systems.

The full range of services are available from the initial planning of the functional safety through to the testing and commissioning and HFL can even develop periodic test procedures for clients to maintain the Safety Instrumented Systems (SISs) and, if requested, can carry out these tests on that basis.
These services include:
• The chairing of HAZOPs and HAZIDs meetings by an experienced process engineer
• Undertake hazard and risk assessments to determine target Safety Integrity Levels (SILs) for Safety Instrumented Functions (SIFs)
• E&I engineers will specify the trips required to carry out the safety functions
• Specify and design, in-house, the logic solver, be it relay based or Safety PLC
• Factory test the software
• Installation and commissioning of the (SISs)
• Confirm that the target SIL operates as specified
• Verification that the design and installation of the SIS Meets the target SIL

Download the PDF Guide to Functional Safety – Compliance with 61508 and 61511