SIL Assessment provided by Magion.

22/1/2018

For a construction company, supplier for the oil & gas industry, Magion has assisted in providing a SIL (Safety Integrity Level) assessment for an LNG terminal in Europe. Magion was contacted by the end user and the construction company, to provide a team of certified SIL engineers to assist with the SIL assessment procedures for the design of a new LNG terminal, consisting of an offloading facility, storage and Regas Unit. The construction company had very little experience with the SIL methodology and relied on Magion’s engineers to reach compliance with the internationals standards as required by the end user and the authorities.

The objective of a SIL assessment is to determine the SIL level of a safety function which is or is to be installed to reduce risk of industrial operations. The SIL assessment will have to be in compliance with the international standard IEC 61511: “Functional safety; safety instrumented systems for the process industry sector”. Ultimately these safety levels will have to be in accordance with levels of risk reduction deemed to be acceptable within the process industry.

Magion’s team consisted of a certified SIL facilitator, leading the assessment process, and a SIL scribe who was responsible for the administration of the assessment, but also actively took part in the assessment process. After a brief period of preparations, the assessment sessions were held in order to assess the relevant safety scenarios and determine the corresponding SIL levels. During these sessions end user and supplier staff members of various disciplines were present to contribute to the assessment process. The involvement of these experts is of paramount importance as their knowledge ensures that the right decisions are being made with respect to installation design and risk mitigation.

After completion of the initial SIL assessment, the results were used as input for a redesign of the installation for the benefit of safe operations. Since the HAZOP and the design of the LNG terminal had been done without compliance to IEC61511 in mind, a gap analysis was required to ensure that all scenarios resulting from the HAZOP studies were covered in the SIL assessment and vice versa. This was also important because of the required traceability of requirements in the SIS Safety lifecycle. Finally, a follow-up session was organized to close the remaining gaps with which the project was successfully completed.