A plant shutdown, or turnaround, is one of the biggest events in a plant’s life. Every day offline costs production, so the work must be planned tightly and done right the first time. In Saudi Arabia, shutdowns at refineries, petrochemical plants, gas plants, power and desalination plants keep a large contractor market busy, especially in Jubail, Yanbu, Ras Tanura and Ras Al Khair.
This guide covers the main planning steps and how the specialist mechanical services fit together.
A typical timeline
| When | What happens |
|---|---|
| 12–18 months before | Set dates and goals; start the work list; identify long-lead materials |
| 6–12 months before | Freeze the scope; detailed planning; choose main contractors |
| 3–6 months before | Order materials; detailed job packs; joint registers; permit planning |
| 1–3 months before | Mobilise contractors; pre-fabricate spools; prepare scaffolding |
| Shutdown | Shut down, isolate, purge, open, inspect, repair, close, test |
| Start-up | Leak checks, hot torque, handover |
| After | Lessons learned and records |
Many plants try to schedule major work in the cooler months, which also helps productivity and safety in the field.
The specialist mechanical services
Most turnarounds need the same core specialist services. Planning them early avoids bottlenecks.
Nitrogen purging
Before equipment can be opened, hydrocarbons must be removed. After the work, oxygen must be removed before start-up. Both are done with nitrogen. See our nitrogen purging procedure and nitrogen purging services.
Pipe cold cutting
Spools that need replacing, tie-ins for new lines and modifications all need cutting, often in areas where hot work is restricted. Cold cutting avoids sparks and prepares weld bevels at the same time. See pipe cold cutting services.
Flange facing
Damaged flange faces found during inspection must be fixed before closing. On-site machining is usually far faster than replacement. See flange facing services.
Bolt torquing and tensioning
Every opened joint has to be closed with the right bolt load. On a large turnaround, this can be thousands of joints. Use our shutdown bolting checklist and see bolt torquing services.
Hydrotest
New or repaired piping and equipment must be pressure tested before start-up. See hydrotest requirements in Saudi Arabia and hydrotest services.
How the services connect
The order of work on a typical piece of equipment is:
- Purge with nitrogen to remove hydrocarbons.
- Open joints (bolting crew) and cut spools where needed (cold cutting crew).
- Inspect, then machine damaged faces (flange facing crew).
- Repair or replace items, weld in new spools.
- Close joints with controlled bolting.
- Test with hydrotest or leak test.
- Purge with nitrogen to remove oxygen.
- Start up, with bolting crew on standby.
Delays in any one service hold up the rest, so having these crews coordinated, or from one contractor, makes a real difference.
Crew planning
- Estimate hours from the job list, not from the last shutdown alone.
- Plan for day and night shifts if the schedule needs it.
- Make sure crews have site passes, medical checks and safety training before the shutdown starts.
- Keep a small reserve of key skills (bolting technicians, machinists) for emergent work.
Permits and safety
Turnarounds bring many contractors onto site at once, which raises the risk. Plan permit offices, gas testing teams and safety supervision to match the peak headcount. Make sure each contractor’s procedures align with the plant’s permit system.
Frequently asked questions
How long does a turnaround last?
From a few days for a small unit to several weeks for a major refinery turnaround.
Should I use one contractor for all mechanical services?
It reduces interfaces and makes scheduling easier. Many plants use one contractor for bolting, cutting, facing, testing and purging, with clear scopes for each.
When should I book specialist crews?
As early as possible. During peak turnaround seasons, experienced crews and large machines are in high demand.
We support shutdowns with all five services in Al Jubail, Yanbu, Ras Al Khair, Rabigh and across the Kingdom. Read our tips on choosing a contractor or contact us.
