The “A” export compressor was removed from service for scheduled maintenance which included breaking of containment for the fuel gas pipework. Following completion of this work and leak testing of the affected pipework, the unit was entered back into service in accordance with an internal procedure. Approximately 4 minutes into the re-start sequence, the enclosure extract gas heads (2 out of 3) alarmed High High in the turbine enclosure. Upon inspection, a ½” instrument fitting was found to be loose, within the enclosure. Following tightening of the loose fitting, a further leak test of the entire fuel gas system within the enclosure was carried out to confirm the pipework was no longer leaking.
- The importance of following procedure / permit when leak testing any system.
- Additional hazard identified on leak test permits to ensure leak test injection point is witnessed when remade and disturbed joint tag returned to Area Authority.
- Update Leak Testing procedure to highlight that leak testing injection points are still to be treated as disturbed joints and the disturbed joint tags to be applied so it can be captured with a service test when the system becomes live.
- Coaching for all leak testers with roll out of new and revised procedures to all leak testers.
Export gas compressor