Refining and petrochemicals
Refinery Turnaround Planning: Interval, Duration, OSHA
US refineries plan routine turnarounds on key units every 3 to 5 years; each keeps a unit offline for several weeks to several months after 1 to 2 years of advance planning, usually in spring or fall. OSHA's process safety standard shapes inspection timing, contractor control, hot work and restart.
Figures come from EIA and AFPM and describe US refining. Other regions have different rules and there is no published benchmark.
How MaintWiz helps: Large turnarounds need one view of scope, permits, parts and progress. The MaintWiz shutdown module gives plant teams one plan for scope, schedule, permits, spares and execution, from the first work package to close-out. See the module · Get the data sheet
By Jai Balachandran · Published · Last reviewed
What MaintWiz adds:Scope, schedule and permits in one planSpares status with SAPReadiness gatesFindings to the planner
Fact block
What do public sources say about refinery turnarounds?
US refinery turnarounds are planned, periodic shutdowns of one or more units for maintenance, inspection and repair, run about every 3 to 5 years on key units and lasting several weeks to several months. 1,2
The T&I term is explained in T&I turnaround and inspection planning. For steel plants see steel plant shutdowns.
Refiners also call a turnaround a turnaround and inspection, or T&I; one Saudi Arabian refinery article describes a five-year T&I cycle. 9
| Item | What public sources say | Source |
|---|---|---|
| Usual term | Turnaround: a planned, periodic shutdown of one or more refinery units for maintenance, inspection and repair | EIA, AFPM |
| How often | Routine turnarounds on key units every 3 to 5 years (US refining) | EIA |
| How long | A unit offline for several weeks to several months (US refining) | EIA, AFPM |
| How far ahead | 1 to 2 years of advance planning; planning teams often begin years ahead | EIA, AFPM |
| Usual window | Spring or fall, when fuel demand is lower | AFPM |
| US regulatory driver | OSHA process safety standard: inspection and test frequency set by manufacturers' recommendations and good engineering practice, and more often if experience requires; hot work permits, contractor duties, change management and pre-startup review | OSHA 1910.119 |
| India driver | Factories Act (replaced by the OSH Code, 2020 from 21 November 2025) 1948 (pressure plant, section 31) and the Boilers Act 2025 (12-month certificate in most cases, once in force) | Factories Act 1948, Boilers Act 2025 |
| Critical-path items | No public, vendor-neutral list found | Searched; see sources |
Read with care. These figures describe US refining. Do not apply them to a petrochemical, chemical or manufacturing plant.
Transitions
Why are the shutdown and startup of a refinery unit hazardous?
Shutting down and starting up a refinery unit are transient operations whose hazards do not exist in steady running, and CSB investigations of Husky Superior (shutdown) and BP Texas City (startup) found weak safeguards, procedures and supervision. 4,5
The rules behind restart are mapped in OSHA PSM turnaround rules.
At Husky Superior in 2018 the explosion occurred while the FCC unit was being shut down for a turnaround. The CSB found the refinery relied entirely on catalyst slide valves to keep air and hydrocarbons apart, and that these valves are known in most of the industry as insufficient safeguards because they are not designed as positive isolation devices. It also found that the shutdown procedure was not aligned with the technology licensor's guidance in place since 1960. 4 At Texas City the day board operator had worked 12-hour shifts, seven days a week, for 29 consecutive days before the 2005 explosions. 5 At the Kuraray plant, a chemical facility, nonessential contractors were welding near a startup after a turnaround. 6 See shutdown safety plan and plant start-up after shutdown.
Software
Can software help with a refinery turnaround?
Software can hold the work list, the permits and isolations, and the daily progress for a large turnaround workforce in one place, so decisions in the morning meeting rest on the same data as the field.
About MaintWiz. MaintWiz is an industrial AI platform with IoT, SAP integration and predictive maintenance (PdM) capabilities. Its shutdown and turnaround module helps plants plan, schedule, execute and close out shutdown work.
Also: product data sheet.
What the shutdown module covers
As described on the MaintWiz shutdown maintenance product page.
- Shutdown calendar and critical-path scheduling, with work order sequencing and dependencies
- Asset prioritization, so the most critical equipment is scoped first
- Resource planning for people, spares, heavy equipment such as cranes, and outsourced vendors
- Electronic permits to work, risk management and contingency plans
- Real-time progress monitoring: schedule adherence, cost variance, quality metrics and risk factors
- Step-by-step checklists, pre-restart testing protocols and post-shutdown analysis
Proof
What MaintWiz customers report
Figures as published in MaintWiz case studies on maintwiz.com. They come from maintenance management projects, not shutdowns.
OSHA
Which OSHA rules shape a US refinery turnaround?
OSHA's process safety standard, 29 CFR 1910.119, names turnaround work in its contractor paragraph and sets the rules for inspection frequency, hot work permits, management of change and the pre-startup review. 3
OSHA PSM turnaround rules maps the rules to each activity.
Separate from OSHA, API inspection codes cover equipment already in service. API 510 covers pressure vessels and applies to hydrocarbon and chemical process vessels placed in service, API 570 covers piping systems, and API 653 covers steel storage tanks built to API 650 or its predecessor API 12C. Check which edition your site or jurisdiction has adopted. 10,11,12
| Paragraph | Requirement | Why it matters in a turnaround |
|---|---|---|
| (h) Contractors | Applies to contractors doing maintenance or repair, turnaround, major renovation or specialty work on or adjacent to a covered process | Host duties for selecting, informing, controlling and evaluating the turnaround contractor workforce |
| (i) Pre-startup safety review | Confirms equipment, procedures, changes and training before hazardous chemicals are introduced | The restart gate; see the restart guide |
| (j)(4) Inspection and testing | Frequency consistent with manufacturers' recommendations and good engineering practice, and more frequent if prior operating experience requires | The reason many inspections wait for the turnaround window |
| (j)(5) Deficiencies | Correct deficiencies outside acceptable limits before further use, or in a safe and timely manner with the necessary means to assure safe operation | Findings during the turnaround need decisions, not deferral by default |
| (k) Hot work permit | Required for hot work on or near a covered process | Permits for welding and cutting during the stop |
| (l) Management of change | Written procedures; replacements in kind excepted | Modifications made during the turnaround |
Lead time
How far ahead should a refinery plan a turnaround?
A large refinery turnaround may involve 1 to 2 years of advance planning, and AFPM says planning teams often begin years ahead. 1,2
For T&I planning and gating in Gulf refining, see T&I turnaround and inspection planning. Equipment guides: heat exchanger turnaround planning, catalyst change-out and fired heater turnaround planning and storage tank turnaround planning.
Work backward from the longest lead item and freeze the scope when the plan is built on it; there is no public freeze-date standard. See how to plan a plant shutdown and shutdown scope management. For the budget side, see shutdown budget planning.
Checklist
What belongs on a refinery turnaround checklist for transient operations?
A refinery turnaround checklist for transient operations should confirm the shutdown procedure against licensor guidance, positive isolation, written safeguards, trained operators, contractor and permit readiness, a fatigue rule and a restart gate.
A free Excel version is available: Refinery turnaround shutdown checklist (.xlsx). Plan the tests before restart with hydrotest and leak test planning.
| Check | Why it matters (public finding) |
|---|---|
| Shutdown procedure checked against the technology licensor's guidance | At Husky Superior the procedure did not match licensor guidance the refinery had held since 1960 |
| Positive isolation, not valves alone, between air and hydrocarbon systems | The CSB found slide valves are not designed as positive isolation devices |
| Steam barrier, purges and other transient safeguards written into the procedure | The CSB found most FCC shutdown safeguards were not implemented or not effective |
| Operators trained and drilled on transient operations | The CSB said procedural safeguards depend on hands-on training such as drills |
| Contractor induction, hot work and confined space permits ready | Several hundred people may be on site |
| Fatigue rule for operators and supervisors | Texas City operators had worked 12-hour shifts for 29 or more consecutive days |
| Restart gate and exclusion zone for nonessential people | See the restart guide |
The checks are a working template based on the CSB findings cited. The general 40-step list is in the shutdown checklist.
Visuals
Save the turnaround charts
Two charts for the turnaround planning room. Click either for the full-size image.
FAQ
Frequently asked questions
How often do refineries have turnarounds?
EIA says routine turnarounds on key units are planned every 3 to 5 years in US refining. 1
How long does a refinery turnaround take?
A unit can be offline for several weeks to several months. 1,2
How far in advance is a refinery turnaround planned?
EIA says 1 to 2 years of advance planning, and AFPM says planning teams often begin years ahead. 1,2
Why are turnarounds scheduled in spring and fall?
AFPM says refiners schedule them around lower fuel demand, typically spring and fall. 2
Which OSHA standard covers refinery turnarounds?
The process safety management standard, 29 CFR 1910.119, whose contractor paragraph applies to turnaround work on or adjacent to a covered process. 3
What did the CSB find at Husky Superior?
During an FCC unit shutdown for a turnaround in 2018, most safeguards that keep air and hydrocarbons apart were not implemented or not effective, and the refinery's process knowledge was insufficient. 4
What does a pre-startup safety review check?
That construction and equipment match design, procedures are in place and adequate, changes were reviewed and training is complete, before hazardous chemicals are introduced. 3
Is there a benchmark critical-path list for refinery turnarounds?
There is no published list. Build yours from your own work list and lead times.
Sources
Sources
- U.S. Energy Information Administration, Refinery Outages: Description and Potential Impact on Petroleum Product Prices
- American Fuel & Petrochemical Manufacturers, Refinery turnarounds 101: What are turnarounds and why do we need them? (17 October 2023)
- OSHA, 29 CFR 1910.119, Process safety management of highly hazardous chemicals
- US Chemical Safety and Hazard Investigation Board, FCC Unit Explosion and Asphalt Fire at Husky Superior Refinery (No. 2018-02-I-WI, 23 December 2022)
- US Chemical Safety and Hazard Investigation Board, Investigation Report: Refinery Explosion and Fire, BP Texas City (Report No. 2005-04-I-TX)
- US Chemical Safety and Hazard Investigation Board, Ethylene Release and Fire at Kuraray America, Inc. EVAL Plant, Pasadena, Texas (No. 2018-03-I-TX, 16 December 2022)
- Government of India, Ministry of Labour and Employment, The Factories Act, 1948
- Government of India, The Boilers Act, 2025 (Act No. 12 of 2025), Gazette text as published by PRS India
- Hydrocarbon Engineering, Ras Tanura refinery completes inspection project (18 February 2018)
- American Petroleum Institute, API 510 Pressure Vessel Inspection Code, 10th edition summary (May 2014)
- American Petroleum Institute, API Standard 570: 5th Edition (Piping Inspection Code)
- American Petroleum Institute, API 653 Tank Inspection, Repair, Alteration, and Reconstruction, 5th edition summary (November 2014)
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