A refinery turnaround is a planned shutdown of a refinery or some of its units for inspection, maintenance, repairs and upgrades. The American Fuel & Petrochemical Manufacturers describes it as “a planned period of extensive maintenance, renovation and capital investment.” Most refineries run a turnaround on each major unit every three to five years.
Key takeaways
- Most refineries are on a three- to five-year turnaround cycle (AFPM).
- A complex turnaround can take more than a million work hours over a couple of months.
- US turnarounds usually happen in spring and fall, around the summer driving season, and EIA says planned maintenance generally peaks in late February and March (EIA).
- Marathon’s 2026 El Paso turnaround cost about $130 million, lasted about 45 days and peaked at up to 2,000 workers (El Paso Inc.).
- Process safety incidents happen five times more often during startup than in normal operation, according to a US Chemical Safety Board digest.
What happens during a turnaround?
Units are shut down, cooled, drained and cleaned so crews can open vessels, columns, heat exchangers and furnaces. The work usually includes:
- Inspecting and repairing vessels, piping and heaters, often to meet inspection deadlines
- Replacing catalyst in reactors
- Cleaning heat exchangers and replacing tube bundles
- Overhauling pumps, compressors and valves
- Installing equipment for capital projects that can only be tied in while the unit is down
How often do refineries do turnarounds?
Most refineries run each major unit on a three- to five-year cycle, and some major units run four to six years between turnarounds (BIC Magazine). Refiners stagger turnarounds across units so the whole refinery is rarely down at once, and sometimes defer them when margins are strong. Citgo, for example, pushed a Lake Charles turnaround from late 2025 into 2026.
When do refinery turnarounds happen?
In the US, most turnarounds fall in spring and fall, before and after the summer driving season. EIA says planned maintenance generally peaks during late February and March, and the fall season usually starts in September (Marketplace). In 2026, refineries running at 97% faced pressure to delay fall work.
How long does a turnaround take and how many people work on it?
Turnarounds last weeks to months. Two examples:
| Turnaround | Duration | Workforce | Cost |
|---|---|---|---|
| Marathon El Paso, 2026 | About 45 days | Up to 2,000 at peak, 206,000 work hours | About $130 million |
| FCL Co-op Refinery, Regina, 2023 | Up to 60 days | 1,200 extra trades, 1,400+ people in total, 510,000 hours | More than $89 million |
Across the industry, Industrial Info Resources tracked about $1.1 billion of US refinery maintenance projects starting in the first quarter of 2026, nearly half at ExxonMobil, Marathon and Valero refineries.
Planning starts years ahead. Marathon told El Paso Inc. that turnaround planning begins up to three to four years before the work.
Turnaround safety
Shutdowns and startups are the riskiest times in a refinery. The Chemical Safety Board notes that process safety incidents happen five times more often during startup than during normal operation, and that half of process safety incidents in one refining study happened during startups, shutdowns and other infrequent events. Turnarounds also bring thousands of contractors on site who may not know the plant, which is why refiners invest heavily in permits, training and supervision.
Who works on a turnaround?
Turnarounds are planned by the refiner’s turnaround managers, planners and schedulers, process and reliability engineers, and inspection teams. The work itself is mostly done by contractors: pipefitters, boilermakers, welders, millwrights, electricians, instrument technicians, insulators, scaffold builders, crane crews and inspectors. See the main oil refinery jobs.
Need engineers for a turnaround or capital project? Apollo Technical recruits process, mechanical, reliability, electrical and controls engineers for refineries and petrochemical plants, from our Houston engineering team. See where every refinery is on our US oil refineries map.
