Turnaround Project Planning Primer
Pre-Turnaround Scheduling (Maintenance)
Scheduling pre-turnaround work must take into account the restrictions imposed for conducting activities in a unit or plant that is running or in the process of being shut down.
Sometimes the extent or scope of the pre-turnaround work exceeds the time allowed and causes a portion of this work to spill over into the turnaround. This means that pre-turnaround work must also be monitored, as it can impact the turnaround schedule and manpower.
Pre-turnaround activities usually fall into these categories:
- Erection of scaffolding
- Staging of equipment, materials
- Tagging of valves to be replaced, leaks
- Removal of insulation
- Demolition / removal of idled equipment
- Testing of valves at the shop
- Fabrication of piping spools, sandblasting, painting, testing
- Mobilization of equipment
- Mobilization of contractors (hiring, drug testing, safety orientation)
- Mobilizing and rigging cranes
- Installation of battery limit blinds
Check your work scope to ensure that all work that can be done ahead of the turnaround is properly identified and flagged as pre-turnaround. Ensure that all the pre-turnaround work is scheduled within the specified pre-turnaround time span. If some activities extend into the turnaround, you should check if the logic is correct or allows improvement to bring it back into the pre-turnaround time span. If the extending activities cannot be pulled back, then you should try to add more pre-turnarounds days (to start the pre-work earlier) until the work fits within the pre-turnaround period.
All of the scaffolding needed to install unit / plant battery limit blinds should be erected pre-turnaround. If the operation of the unit / plant allows it, all other major equipment blind scaffolding should also be erected, so as not to slow down the blinding of the equipment.
Demolition of idled equipment may be allowed in some cases during the pre-turnaround period, depending on safety considerations and possible interference with other work in the unit such as scaffolding, blinding, etc.
Insulation removal may also be dependent upon blinding. Asbestos removal requires special handling, so be sure to review the procedures to allow sufficient time for this task.
Staging and rigging can occur mostly at any time, since these activities seldom interfere with other work.
Rigging a large crane usually involves placing mats, positioning the crane, assembling and rigging the boom and testing. In a congested area, this may take a little longer to accomplish due to safety considerations.
Staging is an important logistical function. How and where temporary buildings, power, air, tool cribs, field parts and materials warehouses, fabricated pipe spools, new (replacement) equipment, cranes, conveyors, drums, temporary structures, dust and runoff containment barriers will be located will have an impact upon the efficiency of the turnaround execution.
Shop fabrication of piping spools is usually scheduled according to pipe type, size or schedule, to minimize material handling. It is best to let the shop schedule the fabrication, unless there is some high priority work identified on the critical path turnaround schedule. The ideal situation is to have all shop fabricated pipe completed, primed and painted (if required), tested and delivered to a shake-out area near the unit or where it is to be installed before the turnaround starts.
All testing of replacement parts should also be completed before the turnaround starts. In particular long delivery items should be tested or verified early to allow sufficient time for replacement or repair, should they prove faulty. Most testing involves valves.