A key issue is how the process equipment will be 'hazard-freed' as it is shutdown. Obviously the Hazids/RAs will state this is done, but in my experience significant hazards (typically locked-in pressure) can remain unless the process to do this is VERY well planned and managed. Problems that I've experienced include: - Copying the same action list as for the last major shutdown some time ago, but not realising there is some subtle difference in the subsequent task lists, or a small modification, that should be taken into account and thus the valving sequence should be different this time. - Organisational pressures to begin the planned shutdown tasks that are on the critical path, resulting in shift handover miscommunications during the hazard-freeing phase. The shutting down preparation plan should include marking up P&IDs (e.g. with highlighter) to show how the hazard-freeing is progressing, and to help ensure no small sections are missed. - If pressure is accidentally 'locked-in' to a small section of equipment that isn't on the critical path, then by the time it's opened up some days later 'everyone knows' that there's no residual pressurised fluids, so the normal checks by permit issuer and receivers seem pointless and aren't carried out conscientiously. - Lots of time pressure towards the planned end date, so making up broken HP joints is done with less checking than required. Using a tag that names those who do this task for each joint helps to ensure no short cuts. - If the schedule goes awry, long working hours by lots of key people, and thus a greater likelihood of errors of both omission and commission. Senior management need to set a good example, including telling someone to take a real rest, if that's needed. Hope these experiences help, and that all goes well.

Many Thanks Both - Useful Stuff Alfasev unfortunately the second of your two links is broken and only leads to a page not found error ? Thanks again though for taking the effort to reply. Cheers

Many Thanks, that link good. Thanks again

You may find HSG253 Safe Isolation of Plant and Equipment useful. Download from http://www.hse.gov.uk/pubns/priced/hsg253.pdf