API 653 Tank Inspection Support in Oklahoma

Short answer: In Oklahoma, an API 653 tank inspection is evaluated and signed by the owner's API 653 Authorized Inspector. The inspector's conclusions rest on NDE data: floor MFL scans with UT prove-up, shell thickness surveys, weld examinations and settlement readings. Atlantis performs that NDE at Cushing tank farms, Oklahoma refineries, pipeline stations, bulk plants and the Tulsa Port of Catoosa, and delivers the results to your inspector in a structured digital report.

Few places on earth hold as much crude oil in aboveground tanks as Cushing, the pipeline hub in Payne County where the US benchmark crude futures contract is delivered. Add refineries at Ponca City, Tulsa, Ardmore and Wynnewood whose sites date back to the 1910s and 1920s, a statewide web of crude gathering and transmission pipelines, gas processing plants, river terminals on the McClellan-Kerr Arkansas River Navigation System and hundreds of bulk plants, and Oklahoma has one of the country's most tank-intensive economies. Its storage-tank regulator also lists API 653 by name among the standards its rules reference. This page explains where Oklahoma's tanks are, what API 653 requires, how the Oklahoma Corporation Commission and federal rules fit together, and exactly what Atlantis does. Atlantis performs the NDE; your API 653 Authorized Inspector remains inspector of record and signs the inspection report. To start, send us your Oklahoma tank list.

Where API 653 tanks are in Oklahoma

Direct answer: Oklahoma's field-erected tanks are concentrated at the Cushing crude hub, at the Ponca City, Tulsa, Ardmore and Wynnewood refineries, at pipeline stations and breakout tanks across the state, at gas processing and NGL facilities in the producing basins, at the Tulsa Port of Catoosa, and at bulk plants and products terminals around Oklahoma City and Tulsa.

Cushing

Dozens of pipelines converge on Cushing, bringing crude from Oklahoma, the Permian, the Rockies and Canada and sending it on to Gulf Coast and Midwest refiners. Storage there exists to hold crude between pipelines, so the tank farms are dominated by large-diameter crude tanks, most with external floating roofs, operated by several midstream companies. Many are pipeline breakout tanks, which brings 49 CFR Part 195 and its API 653 requirement directly into play. Floor condition, floating-roof seals and pontoons, wind girders and settlement of very large tanks on the local soils are the recurring concerns. The area has also experienced induced seismicity; following the magnitude 5.0 earthquake near Cushing in November 2016, operators checked their tank farms, and post-event inspections and settlement surveys remain part of the toolkit an owner and inspector may call on.

Refinery tank fields

Phillips 66 operates the Ponca City refinery in Kay County; HF Sinclair operates the Tulsa refinery's east and west plants; Valero operates at Ardmore; and CVR Energy operates at Wynnewood. Each holds crude, intermediate, blendstock and finished-product tanks, plus asphalt and heated tanks. Because these sites have operated for about a century, some tanks have long histories of repair, re-bottoming and service changes, and older inspection records may use different reference points than modern ones. Re-establishing consistent measurement locations is often the first job.

Pipelines, gathering and gas processing

Crude gathering systems in the SCOOP, STACK and older producing areas feed crude stations with tankage, and transmission pipelines have pump stations with breakout tanks across the state. Gas processing and fractionation plants in central and western Oklahoma store condensate, NGLs and produced water; many NGLs sit in pressure vessels, but atmospheric condensate and water tanks at central facilities are API 653 candidates. Well-site production tanks are excluded from the Commission's storage-tank rules and regulated through its oil and gas programme.

Tulsa Port of Catoosa and river terminals

The Tulsa Port of Catoosa, at the head of the McClellan-Kerr Arkansas River Navigation System, and other river terminals handle liquid bulk, including fuels, chemicals and fertilizer. Tanks on river terraces face groundwater and flood considerations that inland tank farms do not.

Bulk plants and products terminals

Products terminals around Oklahoma City and Tulsa distribute gasoline and diesel across the state, and hundreds of smaller bulk plants hold fuel for agriculture, oilfield service and commercial customers. Bulk plants have their own subchapter in the Commission's storage-tank rules (see below).

What API 653 requires, in plain terms

Direct answer: API 653 is the standard for inspecting, repairing, altering and reconstructing in-service atmospheric steel tanks built to API 650 or API 12C. It requires monthly owner checks, a formal external inspection by the Authorized Inspector, shell thickness measurements and internal inspections whose intervals depend on measured corrosion within code ceilings. The current Fifth Edition has addenda through Addendum 4 (July 2025).

Routine checks. Owner personnel inspect each tank at least monthly for leaks, shell distortion, settlement, coating and roof damage, seal and drain problems and foundation deterioration. On Cushing's floating-roof tanks, standing water or product on the roof, damaged seals and blocked roof drains after heavy rain are typical findings.

Formal external inspection. An Authorized Inspector carries out an external inspection at least every five years, or sooner where shell corrosion is rapid: the code ties the interval to a quarter of the remaining shell corrosion life (RCA/4N). The tank can stay in operation.

Shell UT. When UT thickness measurements are used, the code requires them at least every five years while the corrosion rate is unknown, then at the lesser of half the remaining shell corrosion life (RCA/2N) or fifteen years.

Internal inspection. The out-of-service inspection is where floor condition is established. For a new tank, the first internal is due within ten years, extendable through safeguards (linings, cathodic protection, leak detection, release prevention barriers) to a ceiling of twenty years without a release prevention barrier or thirty years with one. Later intervals are calculated from measured bottom corrosion so that the floor stays above the minimum thickness the code accepts at the next inspection, within the same ceilings, or set by a qualifying risk-based assessment performed by the owner's specialists. That risk-based option is not available for pipeline breakout tanks under PHMSA's rule.

Addendum 4 revised the requirements for measuring tank-bottom plate thickness, so procedures and inspection plans written against earlier text should be checked against the current edition and addendum, available from api.org. Settlement is evaluated using the code's settlement annex, which matters a great deal on very large crude tanks, and repairs and alterations follow the code's examination and testing requirements with API 650 as the construction reference. These decisions rest with the owner and the Authorized Inspector. See API 653 tank inspection intervals explained for more.

Oklahoma regulations that sit on top of API 653

Direct answer: The Oklahoma Corporation Commission's Petroleum Storage Tank Division regulates many aboveground tanks under OAC 165:26, which lists API 653 among its referenced standards and requires SPCC compliance. The Commission's Pipeline Safety Department oversees intrastate gas and hazardous-liquid pipelines, PHMSA covers interstate lines and breakout tanks, and EPA SPCC and OSHA PSM apply. Confirm current requirements with the Commission.

OCC Petroleum Storage Tank Division and OAC 165:26

Oklahoma's aboveground storage tank rules are in Title 165, Chapter 26 of the Oklahoma Administrative Code, administered by the Corporation Commission's Petroleum Storage Tank Division (PSTD). The rules require registration of covered tanks, including tanks at retail sites, public airports, marinas and fleet and commercial facilities above set sizes, and contain a dedicated subchapter for bulk plant facilities, which must register their tanks. The chapter's codes and standards section lists API 653 among the referenced standards, alongside API RP 652 for bottom linings, NFPA 30, UL 142, PEI RP 200 and the federal SPCC rule; check the current rule text for the edition referenced. The rules also require owners of covered tanks to comply with SPCC and keep any required SPCC plan on site, require cathodic protection on protected systems to be tested within six months of installation or repair and at least every three years thereafter, and require records of repairs that restore a tank system after a release or failure to be submitted to PSTD.

The chapter excludes several classes of tank outright, including tanks used in oil and gas exploration and production, farm and ranch tanks, tanks used by public utilities to generate electricity, and tanks used by manufacturers in the production of goods. Exactly which tanks at a refinery, terminal or pipeline site fall under OAC 165:26 depends on the facility and its other regulators, so confirm applicability with PSTD before relying on it.

OCC Pipeline Safety Department and PHMSA

Through PHMSA certification, the Commission's Pipeline Safety Department inspects and enforces federal pipeline safety rules for intrastate natural gas and intrastate hazardous-liquid operators in Oklahoma; PHMSA oversees interstate pipelines. Under 49 CFR 195.432, atmospheric and low-pressure steel breakout tanks on regulated hazardous-liquid pipelines must be inspected in accordance with API 653, excluding the code's alternative risk-based internal inspection interval, while pressurised breakout tanks follow API 510. At Cushing, whether a given tank answers to PHMSA, to the Commission's pipeline programme, or to neither depends on how it is connected and operated. Because the federal rule incorporates an older edition of API 653, operators need procedures that reconcile it with the current edition.

EPA SPCC and OSHA PSM

SPCC-regulated facilities must test or inspect each aboveground oil container for integrity on a regular schedule and after material repairs, following industry standards: API 653 for field-erected tanks and STI SP001 for shop-built tanks. Tanks within OSHA PSM-covered processes, as at the refineries and gas plants, fall under the mechanical-integrity element at 29 CFR 1910.119(j).

Radiography in Oklahoma

Oklahoma is an NRC Agreement State, and radioactive-materials licensing, including industrial radiography, is administered by the Oklahoma Department of Environmental Quality. Repair-weld radiography is performed only by crews licensed for that work in Oklahoma; confirm current licensing authority with the state before planning RT.

NDE methods for API 653 work in Oklahoma

Direct answer: Oklahoma API 653 work leans on floor MFL with UT prove-up for large crude tanks, shell and annular-plate UT, visual examination of floating roofs and seals, corrosion mapping, MT, PT and vacuum-box testing after repairs, PAUT or RT on new welds, and settlement surveys, which matter particularly for Cushing's large-diameter tanks.

Procedures are reviewed by an ASNT NDT Level III and technicians are certified to an SNT-TC-1A written practice. MFL screens the floor quickly, and every reportable indication is proved up with UT so the inspector works from measured remaining thickness. For method trade-offs see MFL versus UT for tank floors; for scope detail see aboveground storage tank inspection.

How Atlantis supports your Authorized Inspector

Direct answer: Atlantis performs the NDE your API 653 inspector's plan calls for, checks data quality before leaving site, and delivers a digital report built for the inspector's evaluation and signature. We are not an Authorized Inspection Agency and we do not supply API-certified inspectors. Our job is the examinations and the data.

1. Scope from the inspector's plan: floor coverage, shell and annular-plate locations, roof and seal examinations, weld examinations and settlement points.
2. Procedure review by an ASNT NDT Level III for the tank's construction, coatings and service, including heated and insulated tanks.
3. Examinations by technicians certified to an SNT-TC-1A written practice: MFL and UT prove-up, shell and annular UT, visual, surface and volumetric methods.
4. Data QA on site: readings checked against calibration records and the previous inspection before demobilising, while access still exists.
5. Digital report in our reporting platform: floor maps, prove-up readings, shell readings by course and location, weld records, photographs, calibration data and technician certifications, using report templates matched to the inspector's file.
6. Inspector evaluation and sign-off: the inspector evaluates, decides on repairs and sets the next dates.
7. Reuse: the same locations next time, with tracking in our inspection-management ERP or a digital twin of the tank farm.

We can calculate corrosion rates and remaining life from our thickness data for the inspector's review; the interval decision belongs to the inspector and the owner under API 653 and any applicable regulation. Atlantis performs the NDE; your API 653 Authorized Inspector remains inspector of record and signs the inspection report. For a midstream operator with tanks at Cushing and along a pipeline system, that separation means one independent NDE data set that any inspector on your roster can work from. Request an NDE scope for your inspector's plan, or see API 653 tank inspection support.

Planning around storm season, heat and pipeline schedules

Direct answer: Oklahoma's weather allows tank NDE most of the year, but spring storm season, summer heat and winter ice storms all shape scheduling. Out-of-service work on large crude tanks must also fit shipper schedules and hub inventory, so internal inspections are planned well in advance and coordinated with pipeline operations.

Spring storms and wind. Severe thunderstorms, hail and tornadoes are part of an Oklahoma spring. Hail damages roof coatings and floating-roof components, and high winds are a real structural concern for tanks that have been emptied for inspection, since an empty tank has none of the product weight that resists wind loads. Owners and their engineers often plan outages and temporary measures with that in mind, and external visual inspections after storm season give the inspector an early look at roof and seal damage.

Summer heat. Shell temperatures in an Oklahoma summer affect UT readings, couplant performance and technician safety, especially inside tanks and on black-coated roofs. Early-morning work windows, high-temperature couplants and temperature-corrected measurement help keep data accurate.

Winter ice. Ice storms make stairways, roofs and wind girders hazardous and can stall work for days. Internal inspections are rarely planned for the depth of winter.

Pipeline and hub schedules. At Cushing and at crude stations, taking a large tank out of service means coordinating with shippers and other tanks in the system. Cleaning a crude tank with heavy sludge can take longer than the NDE itself, so book the crew to arrive the day the tank is released for entry. Book a scoping call with your outage plan.

API 653 inspection support across Oklahoma

Direct answer: Atlantis mobilises crews to tank sites throughout Oklahoma, with the schedule agreed during scoping: Cushing, Tulsa and the Port of Catoosa, Ponca City, Oklahoma City, Ardmore, Wynnewood and the producing basins. The Tulsa pages below cover tank, corrosion, piping and vessel inspection in more detail.

• Tulsa and northeast Oklahoma: tank inspection in Tulsa and corrosion inspection in Tulsa.
• Refinery and terminal piping and pressure equipment: piping inspection in Tulsa and pressure vessel inspection in Tulsa.
• Cushing, Ponca City, Oklahoma City, Ardmore and Wynnewood: served by mobilised crews; include the site address with your tank list.

Tank piping, manifolds and pressure vessels at the same sites follow their own codes; see our companion hubs for API 570 piping inspection in Oklahoma and API 510 pressure vessel inspection in Oklahoma, and the statewide NDT inspection services in Oklahoma page. Pipeline operators can also see pipeline inspection services.

What to send us for a quote

Direct answer: Send your tank list, the last API 653 reports, your inspector's plan, the cleaning and access status, and your dates. We return a scoped NDE quote within 24 hours.

1. Tank list and drawings: tank IDs, diameter, height, roof type, product, year built, plate thicknesses, bottom history, lining, cathodic protection, PSTD registration where applicable, and whether the tank is a pipeline breakout tank.
2. Previous reports: external and internal reports, floor maps, shell readings and settlement surveys, so we can repeat locations and corrosion rates stay valid.
3. The inspector's plan: examinations, coverage, acceptance references and report format, with the name of your Authorized Inspector or agency.
4. Access and cleaning: service status, cleaning contractor, gas-free and confined-space arrangements, roof access and any wind-restraint measures for emptied tanks.
5. Dates: PHMSA, SPCC or internal due dates, outage windows, shipper constraints and site safety orientation needs.

Get a quote within 24 hours.

Frequently asked questions: API 653 tank inspection in Oklahoma

Who can perform an API 653 inspection in Oklahoma?

An API 653 Authorized Inspector, working for the owner or an inspection agency, is responsible for the inspection and signs the report. Qualified NDE technicians gather the data. Atlantis performs that NDE with ASNT-certified technicians under Level III oversight and delivers results to your inspector.

Does the Oklahoma Corporation Commission require API 653?

The Commission's aboveground tank rules (OAC 165:26) list API 653 among their referenced codes and standards and require covered owners to comply with SPCC, which relies on industry standards for integrity testing. Which tanks fall under the rules depends on use and exclusions. Confirm applicability with the Petroleum Storage Tank Division.

Are Cushing tanks regulated by PHMSA?

Many Cushing tanks are breakout tanks on hazardous-liquid pipelines. PHMSA oversees interstate systems and the Commission's Pipeline Safety Department oversees intrastate ones; either way, 49 CFR 195.432 requires API 653 inspection without the code's alternative risk-based internal interval.

Are oilfield production tanks covered by OAC 165:26?

No. Tanks used in oil and gas exploration and production are excluded from the Commission's aboveground storage tank chapter and handled through its oil and gas programme. Larger atmospheric tanks at central gathering and processing facilities may still be inspected to API 653 by owner choice or other rules.

How often does a crude tank need an internal inspection?

For a new tank, within ten years, extendable by credited safeguards up to twenty years, or thirty with a release prevention barrier. Later intervals follow measured floor corrosion within the same ceilings. Breakout tanks cannot use the risk-based alternative. The inspector and owner set the actual interval.

Should a tank be inspected after an earthquake or major storm?

That is the owner's and inspector's call, but external visual examination and a settlement survey compared with the baseline are common follow-ups after a significant earthquake, flood, hail or wind event. Atlantis can collect that data quickly once access is safe.

Is Atlantis an Authorized Inspector?

No. We are not an Authorized Inspection Agency and we do not supply API-certified inspectors. We perform and document the NDE; your inspector evaluates it and signs.

Can you inspect while the tank stays in service?

Yes for shell UT, corrosion mapping, external visual examination including floating-roof and seal checks, and settlement readings. Floor scanning and internal weld examination need the tank emptied, cleaned and gas-free.

What certifications do your technicians hold?

Technicians are certified to an ASNT SNT-TC-1A written practice for each method, with procedures reviewed by an ASNT NDT Level III. Radiography is performed only by crews licensed for industrial radiography in Oklahoma.

Do you perform RBI or fitness-for-service assessments?

No. Those are performed by the owner's engineers or specialist consultants. Atlantis supplies the floor, shell and weld data they rely on.

Do you offer API 653 certification training?

No. Atlantis provides ASNT SNT-TC-1A NDT training only, including NDT training in Oklahoma. For the API certification route, see our API inspector career guide.

How soon can a crew reach Cushing or Tulsa?

Crews are mobilised to your site on a schedule agreed during scoping, built around your outage window and shipper constraints. Send tank details for a quote within 24 hours.

Plan your Oklahoma tank inspections

From a floor scan on a Cushing crude tank to a shell survey at a Tulsa terminal or a post-storm check at a bulk plant, start with your inspector's plan and your tank list. Send us your tank list, or see NDT consulting in Oklahoma for Level III procedure support.

More Atlantis NDT services in Oklahoma

• NDT training and certification in Oklahoma
• Level III consulting in Oklahoma
• NDT inspection services in Oklahoma
• API 510 pressure vessel inspection support in Oklahoma
• API 570 piping inspection support in Oklahoma
• Practical NDT simulator in Oklahoma

Part of the wider aboveground storage tank inspection service at Atlantis NDT.