API 510 Pressure Vessel Inspection Support in Louisiana

Short answer: In Louisiana, API 510 inspection of refinery, chemical, fertilizer and LNG pressure vessels is run by the owner's API 510 Authorized Inspector (AI), who sets the plan, evaluates the results and signs the report. Atlantis NDT supplies the nondestructive examination behind it: UT thickness at CMLs, automated corrosion mapping, PAUT and TOFD on welds, WFMT for wet H2S, amine and ammonia cracking, RT, MT, PT and VT. Atlantis performs the NDE; your API 510 Authorized Inspector remains inspector of record and signs the inspection report.

Louisiana packs an unusual amount of pressure equipment into two corridors: the Mississippi River between Baton Rouge and New Orleans, and the Calcasieu and Sabine area around Lake Charles and Cameron Parish. Between them sit some of the largest refineries in the United States, a world-scale nitrogen fertilizer complex, chlor-alkali and vinyls plants, and several LNG export terminals. The state boiler programme focuses on boilers, so the API 510 programme for unfired vessels is driven mainly by federal process safety rules, the owners' mechanical integrity standards and their insurers. This page explains how that works in Louisiana and where an independent NDE contractor fits. To start, request an NDE scope for your AI's plan.

Where API 510 pressure vessels are in Louisiana

Direct answer: Louisiana's API 510 population is concentrated in the Baton Rouge to New Orleans river corridor (refining, chemicals, fertilizer), the Lake Charles and Cameron Parish cluster (refining, petrochemicals, LNG), the lower river and Plaquemines Parish (refining and new LNG), and smaller gas, paper and power sites across north and central Louisiana.

Baton Rouge, Plaquemine, Geismar and the upper river

The ExxonMobil Baton Rouge refinery and chemical plant is one of the largest integrated sites in the country. Upriver and across the river, the Dow Louisiana Operations site at Plaquemine runs chlor-alkali, olefins and derivatives units, and Geismar hosts a cluster of chemical producers making isocyanates, polyols, ethylene oxide derivatives and specialty chemicals. Vessel types include reactors, distillation columns, chlorine and caustic service equipment, ethylene oxide reactors and storage, and large numbers of shell-and-tube exchangers. Caustic stress corrosion cracking, chloride cracking of stainless steels and wet chlorine corrosion are typical damage mechanisms.

Donaldsonville, Convent, Garyville and the River Parishes

The CF Industries Donaldsonville complex is among the largest nitrogen fertilizer manufacturing sites in the world. Ammonia plants carry high-pressure synthesis converters, ammonia separators and refrigerated or pressurised ammonia storage, where ammonia stress corrosion cracking of carbon steel welds is a recognised concern and wet fluorescent magnetic particle inspection of internal welds is a standard technique. Downriver, Marathon's Garyville refinery is one of the largest in the country, with crude, coking, hydroprocessing and sulfur recovery units. The Norco area hosts the Shell Norco chemical complex and Valero's St. Charles refinery.

New Orleans, Chalmette, Meraux and Plaquemines Parish

Below New Orleans, the PBF Chalmette refinery and Valero's Meraux refinery sit on the east bank, and Plaquemines Parish has become a growing LNG location with Venture Global's Plaquemines LNG. Refinery vessel scope here mirrors the upper river, while new LNG trains introduce acid gas removal (amine) absorbers, dehydration beds and cryogenic separators, with stainless and nine-percent-nickel materials in cold service.

Lake Charles, Westlake, Sulphur and Cameron Parish

Southwest Louisiana combines the Citgo Lake Charles refinery, the Phillips 66 Lake Charles refinery, Sasol's Lake Charles chemical complex and Westlake's chlor-vinyls and olefins operations with LNG export terminals at Sabine Pass, Cameron LNG and Calcasieu Pass. That mix puts amine contactors, sour water strippers, hydrotreater reactors, ethylene cracker quench and separation vessels and LNG pre-treatment equipment within a short drive of each other. Hurricanes Laura and Delta in 2020 also left owners here with a strong appreciation of external inspection after storm damage.

North and central Louisiana

Away from the coast, the Shreveport refinery, natural gas processing in the Haynesville area, paper mills around West Monroe and Bogalusa, and power stations across the state add digesters, recovery-boiler auxiliaries, separators, deaerators and air receivers. Pulp and paper vessels bring their own damage mechanisms (caustic and sulfide attack in digesters and liquor tanks), and are often inspected under the same owner programme as the site boilers, which in Louisiana fall under the Office of State Fire Marshal.

What API 510 requires, in plain terms

Direct answer: API 510 governs in-service inspection, repair, alteration and rerating of pressure vessels. Each vessel needs an inspection plan, periodic external inspections, internal or on-stream inspections tied to corrosion rate and remaining life, pressure-relief device testing, and AI-authorised repairs. Intervals come from the code, the owner's programme and, where used, an RBI assessment.

API 510 is published by the American Petroleum Institute (api.org). Confirm requirements against the edition your programme has adopted; older editions circulating online are not current. Paraphrasing the current code: external inspections are performed at intervals not exceeding the lesser of five years or the internal/on-stream interval; internal or on-stream inspections at intervals not exceeding the lesser of half the calculated remaining life or ten years; and, where remaining life is under four years, at an interval up to the full remaining life but not more than two years. A documented RBI programme meeting the code's conditions can replace these fixed limits. Pressure-relief devices, inspected and tested following API RP 576, typically run on intervals of no more than five years in typical process service and ten years in clean, non-fouling, non-corrosive service unless documented experience or RBI justifies longer.

Three API 510 concepts shape most Louisiana NDE scopes:

Condition monitoring locations. CMLs are the fixed points where thickness is measured repeatedly. Corrosion rates (short-term and long-term) and remaining life are calculated from them, so CML naming, probe selection and calibration consistency matter more than raw speed.
On-stream substitution. The code allows on-stream inspection in place of internal inspection under defined conditions. In practice the AI needs to be confident the damage is predictable and that the external NDE can find it. Good corrosion maps and sized weld indications are what make that case.
Damage-mechanism-driven planning. Inspection plans should address the specific damage mechanisms the vessel is susceptible to, using API RP 571 as the reference. In Louisiana that list is long: wet H2S damage, amine cracking, ammonia SCC, caustic SCC, chloride SCC, HTHA in hydroprocessing and CUI almost everywhere.

Repairs, alterations and rerating are authorised by the AI and performed by a qualified repair organisation; many Louisiana owners require National Board Inspection Code compliance and an R-stamp holder for pressure-boundary repairs. For the arithmetic behind intervals, see API 510 interval calculation explained, and for sour service, API 510 intervals in wet H2S service.

NDE methods for API 510 work in Louisiana

Direct answer: Louisiana vessels need UT thickness and corrosion mapping everywhere, WFMT for cracking in wet H2S, amine and ammonia service, PAUT and TOFD for weld integrity and flaw sizing, and RT, PT, VT and ET in specific services. The table links each method to the Louisiana equipment where it is most used.

Method	What it finds	Typical Louisiana application	Governing reference
UT thickness at CMLs	General wall loss; corrosion-rate and remaining-life data	Crude, vacuum and coker vessels on the river; gas separators in the Haynesville	API 510; ASME Section V
Automated UT corrosion mapping	Localised thinning, HIC and blistering in plate, laminations	Lake Charles amine contactors and sour water strippers, scanned on-stream before turnarounds	API 510; ASME Section V; API 571
WFMT (wet fluorescent MT)	Surface-breaking cracks in welds and HAZ	Ammonia converters, separators and storage around Donaldsonville; amine regenerators; caustic service	ASME Section V Article 7; API 571
PAUT	Weld cracking and fusion flaws, sizing from the outside	Weld examination on hydroprocessing and chemical reactors without entry	ASME Section V Article 4; owner specification
TOFD	Through-wall height of planar flaws; fast weld screening	Long seams on columns and heavy-wall reactors; repair verification	ASME Section V Article 4
RT	Volumetric weld flaws; profile RT for wall loss	Small-bore nozzles, repair welds, insulated attachments	ASME Section V Article 2; NBIC Part 3
PT and VT	Surface cracks on stainless and non-magnetic alloys; overall condition	Stainless chlorine/caustic equipment, LNG cold-service vessels	ASME Section V Articles 6 and 9; API RP 572
ET	Tube thinning, pitting and cracking	Exchanger bundles in Geismar and Plaquemine chemical units	ASME Section V Article 8

The point of the table is that two Louisiana vessels of the same size can have nothing in common NDE-wise. An ammonia separator is a cracking problem that needs WFMT on clean internal welds; a crude tower overhead drum is a corrosion-rate problem that needs dense thickness data; a chlorine-service stainless vessel needs PT and close attention to chlorides. Our API 571 damage mechanisms guide covers these mechanisms in depth. Industrial radiography in Louisiana is licensed by the Louisiana Department of Environmental Quality radiation programme (Louisiana is an NRC Agreement State; confirm current licensing authority with the state), and RT is performed by crews licensed in Louisiana.

How Atlantis supports your Authorized Inspector

Direct answer: Atlantis turns the AI's inspection plan into procedure-controlled NDE, executes it with ASNT-certified technicians under Level III oversight, and delivers a digital report the AI can evaluate and sign. We are not an Authorized Inspection Agency and we do not supply API-certified inspectors.

Along the river, many inspection firms bundle the AI with the NDE crew. Atlantis deliberately sells only the NDE. Your AI may be an owner employee, part of a corporate inspection organisation, or a third-party inspector you already contract; in every case they get independent data and stay fully in control. Our handoff runs like this:

Plan intake. We take the AI's vessel list, CML map, inspection type and damage mechanisms of concern. If CMLs are poorly located for the active mechanism, we say so, and the AI decides.
Procedures under Level III review. Written techniques for UT, corrosion mapping, PAUT/TOFD, WFMT and other methods, with reporting thresholds from the owner's specification.
Field execution. Crews mobilised to your site; on-stream work scheduled around unit operations, internal work around the turnaround and vessel entry permits.
Data QA before demobilisation. Readings compared with history; anomalies re-shot while access exists.
Digital report. CML IDs, readings, maps, indications, photos, calibration, equipment and technician certifications in Atlantis's reporting platform.
AI evaluation and sign-off. The AI determines rates, remaining life, next intervals and repairs.
Next interval. The data structure carries forward so trends stay comparable.

When the owner's engineers run RBI or commission a fitness-for-service assessment, our maps and flaw sizes are inputs; those assessments are done by the owner's engineers or a specialist. See API 510 pressure vessel NDE support and pressure vessel inspection services.

Louisiana regulations that sit on top of API 510

Direct answer: Louisiana's boiler law is administered by the Office of State Fire Marshal (OSFM) and is aimed at boilers; according to the National Board's jurisdictional synopsis, pressure vessels are built to ASME Section VIII when the owner requires it rather than under a state field-inspection programme. Process vessels are driven by OSHA PSM 1910.119(j) and EPA RMP. Confirm current requirements with the OSFM boiler section.

Office of State Fire Marshal. The Louisiana boiler statute sits in Title 23 of the Louisiana Revised Statutes, with rules in Title 55 of the Louisiana Administrative Code, and the Boiler Inspection Section of OSFM is the jurisdictional authority. Boilers receive certificate inspections by state deputy inspectors or by insurance-company inspectors commissioned by the state, and repairs follow the National Board Inspection Code with R-stamp organisations. Air tanks and other unfired vessels are a grey area in public summaries, so do not assume either way: confirm with OSFM whether a particular vessel falls under state inspection.

OSHA PSM and EPA RMP. Louisiana has no state OSHA plan for private-sector employers, so federal OSHA enforces 29 CFR 1910.119. Its mechanical integrity element requires written procedures, inspection and testing following RAGAGEP, documented inspections, and correction of deficiencies before further use or in a safe and timely manner. For pressure vessels, API 510 is the RAGAGEP most owners cite. EPA's Risk Management Program (40 CFR Part 68) Program 3 applies equivalent mechanical integrity requirements to many of the same Louisiana facilities, and LDEQ administers air permits that influence turnaround timing.

LNG terminals. LNG export terminals are also subject to federal regulators (FERC for siting and PHMSA under 49 CFR Part 193 for LNG facilities), whose requirements sit alongside the owner's API 510 programme for process vessels. Confirm which code governs each item of equipment with the operator's compliance team.

Pipelines at the fence line. Intrastate pipeline safety in Louisiana is handled by the Pipeline Safety division within the Louisiana Department of Energy and Natural Resources (formerly the Department of Natural Resources), acting with PHMSA. That governs pipelines, not plant vessels, but launcher and receiver barrels and slug catchers at plant boundaries sometimes fall between programmes and should be assigned explicitly. For how API 510 inspectors and National Board commissioned inspectors differ, see API 510 vs NBIC commissioned inspector.

Planning around turnarounds and hurricane season in Louisiana

Direct answer: Schedule internal inspections into planned turnarounds, run on-stream NDE months ahead to decide which vessels must be opened, and build hurricane season (June to November) into the plan, including post-storm external inspections.

Louisiana turnaround seasons overlap with Texas, so NDE crews, scaffolding and radiography are in short supply at the same time across the Gulf Coast. The practical answer is to move work out of the outage window:

On-stream first. Corrosion mapping on amine, sour water and crude overhead vessels, and PAUT on welds of concern, completed well before the turnaround so the AI can decide which vessels genuinely need opening.
Fertilizer plant outages. Ammonia plants run long between outages, so every outage must capture WFMT on converter, separator and storage welds, plus thickness and hardness checks the plan calls for. Surface preparation time for WFMT is often the bottleneck and must be in the schedule.
LNG trains. New trains generate baseline inspections and early-life inspections; good baselines make later rate calculations meaningful.
Hurricane season. Coastal units shut down ahead of storms. Afterwards, the AI typically wants external inspections of vessels exposed to flooding, wind loads or impact, with UT at insulation exposed to floodwater to check for accelerated CUI. Having baseline data before the season makes those post-storm checks quicker to evaluate.

River-corridor sites also deal with high humidity and frequent rain, which make insulation integrity and CUI a constant external-inspection theme. See CUI inspection for how we support CUI screening.

API 510 inspection support across Louisiana

Direct answer: Atlantis supports API 510 programmes from Baton Rouge to New Orleans and across the Lake Charles area. Crews are mobilised to your site, and the schedule is agreed during scoping.

Baton Rouge and the upper river: pressure vessel inspection in Baton Rouge, with corrosion inspection, piping inspection, weld inspection and third-party inspection. Tank owners nearby can see API 653 tank inspection in Baton Rouge and tank inspection services.
New Orleans, Chalmette, Meraux and the lower river: pressure vessel inspection in New Orleans, plus corrosion, piping, weld and tank inspection.
Lake Charles and Cameron Parish: third-party inspection in Lake Charles for refinery, petrochemical and LNG sites.

The sibling hubs API 570 piping inspection in Louisiana and API 653 tank inspection in Louisiana cover piping and storage tanks at the same sites. For all methods across the state see NDT inspection services in Louisiana; to build in-house NDE skills, see ASNT NDT training in Louisiana.

Keeping Louisiana vessel data usable

Direct answer: Corrosion rates are only as good as the CML history behind them. Atlantis delivers structured digital data that keeps your CML numbering, documents calibration and qualifications, and can feed a digital twin or inspection-management ERP.

Large river-corridor sites often have decades of vessel history spread across contractor formats. When a contractor renames CMLs or changes probe types without recording it, the AI can end up with a false corrosion rate, and therefore a wrong interval. We map readings to your existing CML IDs, record instrument, probe and calibration for each set, and explain every location we could not read. Results can be linked to a digital twin of the unit, managed in our inspection-management ERP, and reported in the formats shown on NDT report templates.

What to send us for a Louisiana quote

Direct answer: Send the vessel list and data reports, the AI's plan and CML map, the last API 510 report, the damage mechanisms of concern, access and cleaning status, and target dates. We quote within 24 hours of having that information.

Vessel tags, U-1 data reports or nameplate data, drawings, materials and any PWHT or cladding details.
The previous API 510 inspection report and thickness history.
The AI's inspection plan, CML map and damage mechanism review (wet H2S, amine, ammonia SCC, caustic, HTHA, CUI).
Inspection type (external, internal, on-stream) and whether vessels will be cleaned, gas-freed and open.
Access: scaffold, insulation removal, surface temperatures, confined-space requirements.
Dates, turnaround window, TWIC needs for river and port facilities, site orientation.

Send us your vessel list and we will come back with questions or a scope.

Frequently asked questions: API 510 in Louisiana

Who does API 510 pressure vessel inspection in Louisiana?

An API 510 Authorized Inspector, employed by the owner-user or an inspection agency, directs and signs the inspection. NDE within it is performed by qualified examiners. Atlantis performs that NDE and supplies the data; your AI remains inspector of record.

Does Louisiana require pressure vessel inspections by state law?

Louisiana's OSFM boiler programme centres on boilers; unfired process vessels are generally driven by OSHA PSM, EPA RMP, insurers and the owner's programme rather than a state field-inspection schedule. Some vessel categories may be treated differently, so confirm with the OSFM Boiler Inspection Section.

How often do pressure vessels need API 510 inspection?

External inspections at no more than the lesser of five years or the internal interval; internal or on-stream inspections at no more than half the remaining life or ten years, whichever is less, with a two-year cap under four years of remaining life. RBI can set different intervals. The AI decides.

Is Atlantis an Authorized Inspector or inspection agency?

No. We are not an Authorized Inspection Agency and we do not supply API-certified inspectors. We supply independent NDE that your AI evaluates and signs.

How do you inspect ammonia vessels for stress corrosion cracking?

The usual approach is WFMT on internal welds and heat-affected zones after abrasive cleaning, supplemented by UT or PAUT to size any indications. Coverage and acceptance are set by the owner's plan; we execute, document and report.

Can amine and sour water vessels be inspected on-stream?

Yes, automated UT corrosion mapping and PAUT can be run from the outside to find HIC, blistering and weld cracking. Whether that supports an on-stream inspection in place of an internal inspection is the AI's decision under API 510.

Do you inspect LNG terminal pressure vessels in Cameron or Plaquemines Parish?

Yes. LNG pre-treatment, dehydration and separation vessels need UT, PAUT, PT and VT suited to stainless and low-temperature materials. The operator's compliance team confirms which items fall under API 510 and which under other federal LNG requirements.

What certifications do your technicians hold?

Technicians are certified to an ASNT SNT-TC-1A written practice and work under ASNT NDT Level III oversight. Certificates and vision records are included in the report.

Do you perform RBI or fitness-for-service in Louisiana?

No. We provide the thickness maps and flaw sizes that RBI and fitness-for-service studies use; the owner's engineers or a specialist perform those assessments.

Do you offer API 510 exam training?

No. Atlantis trains to ASNT SNT-TC-1A only. See the API inspector career guide for the certification route and NDT training in Louisiana for NDE skills.

How fast can you mobilise to Baton Rouge or Lake Charles?

We quote within 24 hours once we have the scope, and the mobilisation date is agreed during scoping around permits, turnarounds and storm season.

Next step

Whether you face a fertilizer outage, a refinery turnaround or post-storm external inspections, book a scoping call or get a quote within 24 hours. Atlantis performs the NDE; your API 510 Authorized Inspector remains inspector of record and signs the inspection report.

More Atlantis NDT services in Louisiana

Part of the full range of pressure vessel inspection services from Atlantis NDT.

Speak to an ASNT NDT Level III

Atlantis NDT provides ASNT Level III consulting, NDT training to ASNT SNT-TC-1A, inspection management software and independent report validation. Request a free consultation and we will return a tailored quote — affordable, accessible and fully customizable to your programme.