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The general preparations that are to be done for a unit shutdown
Phase1: preparation
1-Management determines what repair work and upgrades are to be done during the turnaround.
2- Engineering planning, diagrams, and so on are completed or repair and project work for the turnaround. Plant departments and maintenance are notified of the shutdown and planned work.
3 – Logistics of materials, supplies, and tools needed for shutdown are determined.
4- A list is prepared of equipment to be inspected.
5- The shutdown schedule is continually reviewed to determine ways to reduce turnaround time.
6- Shutdown procedures, blind lists, and check-off lists are verified as up-to-date.
7. Additional operations and maintenance personnel are scheduled for the shutdown.
Phase 2: unit shutdown
1- Plans, including training, are prepared to minimize the flaring of materials, equipment damage accidents.
2- Unit feed and temperature are slowly decreased to prevent damage from thermal shock.
3- Unit vessels and piping are deinventoried as much as possible to recover all unit hydrocarbons.
4- After all hydrocarbons have been pumped ot or drained from piping and vessels, purge with an inert gas.
5- Insert blinds, aerate, and use gas doctors to check the lower explosive limits (LEL) of each vessel after equipment is hydrocarbon free.
6- Check vessels daily for LEL before allowing entry and check hot work jobs while maintenance and contractors are doing turnaround work.
7- Engineering and operations personnel do a final inspection before equipment is closed up.
