API 570 Piping Inspection Support in Mississippi

Short answer: In Mississippi, API 570 inspection of refinery, LNG, chemical, fertilizer and terminal piping is planned, evaluated and signed by the owner's API 570 Authorized Inspector (AI). No Mississippi rule names API 570; the obligation comes mainly from federal OSHA process safety management and EPA's Risk Management Program. Atlantis NDT performs the examinations behind the AI's plan: UT thickness at condition monitoring locations (CMLs), corrosion mapping, profile radiography, guided-wave screening and weld examination by PAUT, TOFD, MT and PT. Atlantis performs the NDE; your API 570 Authorized Inspector remains inspector of record and signs the inspection report.

Mississippi's piping population is dominated by one very large site and a handful of specialised ones. At Pascagoula, Chevron's refinery is the largest in the state and one of the larger refineries in the country, with an LNG terminal, chemical plants and the shipyard alongside it on Bayou Casotte and the Pascagoula River. Inland, two specialty refineries run naphthenic oils and asphalt; a fertilizer complex at Yazoo City handles ammonia; a titanium dioxide plant on the coast runs chlorine chemistry; the Collins pipeline hub moves refined products north; and salt-dome gas storage sits under the Pine Belt. Each of these needs a different API 570 programme. This hub sets out where the piping is, what the code requires, which methods fit Mississippi damage mechanisms, how the federal and state bodies divide the work, and what Atlantis delivers to your AI. To start, request an NDE scope for your AI's inspection plan.

Where API 570 piping is in Mississippi

Direct answer: Mississippi's API 570 piping is concentrated at the Pascagoula refinery and the Bayou Casotte industrial harbour, at the Vicksburg and Sandersville specialty refineries, at the Yazoo City nitrogen fertilizer complex, at coastal chemical plants such as the DeLisle titanium dioxide plant, at the Collins pipeline terminals, and at gas-processing, gas-storage and power facilities across the state.

Pascagoula and Bayou Casotte

The Pascagoula refinery runs crude, vacuum, conversion, hydroprocessing, reforming and sulfur units connected by many miles of process and interconnecting piping, plus a deep-water marine terminal that receives crude by tanker. A site of that size will normally run a mature API 570 programme with a large CML database, its own inspection staff and contract NDE crews brought in for surveys and turnarounds. The work that matters most here is consistency: thousands of CMLs measured the same way, at the same points, with readings that can be trended over many intervals. Beside the refinery, the Gulf LNG terminal on Bayou Casotte runs cryogenic piping in stainless steel, chemical plants handle aromatics and intermediates, and Ingalls Shipbuilding operates on the Pascagoula River. Ship piping and nuclear-plant piping follow their own rules and are outside this page.

Vicksburg and Sandersville

Ergon's refinery at Vicksburg on the Mississippi River specialises in naphthenic lubricating oils and asphalt, and Hunt Southland Refining operates at Sandersville near Laurel. Specialty and asphalt refineries run heavy, hot, viscous products in insulated and heat-traced piping, so corrosion under insulation, tracing failures and high-temperature UT are routine considerations. Naphthenic crudes also bring naphthenic acid corrosion into the damage mechanism review for hot circuits, which pushes CML density up at elbows, tees and high-velocity points.

Yazoo City and the fertilizer industry

CF Industries' Yazoo City complex produces ammonia-based nitrogen fertilizers. Ammonia, nitric acid, urea and ammonium nitrate solution piping each has its own damage mechanisms, from stress corrosion cracking in ammonia service to nitric acid attack where material selection or welding is wrong. Owners of these plants apply API 570 discipline to process piping that falls under PSM, where ammonia inventories almost always make the process covered.

The coast: DeLisle, Gulfport and Biloxi

At DeLisle, near Pass Christian, a large titanium dioxide plant uses the chloride process, with chlorine, titanium tetrachloride and acid piping in demanding service. Gulfport and the coastal counties have fuel terminals, port facilities and military installations whose fuel systems are inspected under owner or federal programmes. All coastal piping shares the same salt air, humidity and hurricane exposure as Pascagoula.

Collins and the Pine Belt

Collins, in Covington County, is a major refined-products hub on the Colonial Pipeline, with terminals operated by several pipeline and wholesale companies. Terminal piping between pipeline delivery points, tanks, pumps, manifolds and loading racks is a typical API 570 population, and the boundary with the regulated pipeline must be documented. Around Hattiesburg and the Pine Belt, natural gas is stored in salt domes; storage facilities, compressor stations and gas-processing plants elsewhere in the south of the state combine regulated pipeline piping with plant piping the owner may manage under API 570 principles.

Power and pulp and paper

Mississippi Power and Entergy run gas-fired and other generating plants whose fuel-gas and chemical-feed piping may sit under an owner programme, while power piping normally follows ASME B31.1 practice. Pulp and paper mills in the east and north of the state run liquor, chlorine dioxide and caustic piping where owners often borrow API 570's circuit and CML approach.

What API 570 requires, in plain terms

Direct answer: API 570 governs in-service inspection, repair, alteration and rerating of metallic process piping and its pressure-relief devices. The owner divides piping into circuits, assigns a service class by leak consequence, places CMLs where damage is expected, and schedules thickness and external inspections by class and remaining life, or by a qualifying RBI programme. The AI evaluates and signs.

The current edition is the fifth edition, published in February 2024 alongside API RP 574, with an addendum issued in 2025. API's own summary of the changes highlights a defined Inspection Supervisor role, stronger pressure-relieving device requirements and rules on deferring inspection repair recommendations. Copies found online are usually older editions, so work from a licensed current copy. In our own words, the parts that shape an NDE scope are:

• Roles. The owner runs the programme. The authorized piping inspector plans, evaluates and accepts; examiners such as Atlantis technicians measure and report but do not evaluate; repair organisations repair what the inspector authorises; piping engineers handle alterations and rerates.
• Scope. Hydrocarbon, chemical and other flammable or toxic process services are in scope; utility services can be added at the owner's option. New construction stays under ASME B31.3.
• Service classes. Class 1 for services where a leak could quickly become an emergency, such as flashing light hydrocarbons; Class 2 for most unit piping; Class 3 for flammables that do not significantly vaporise and many off-site lines; and, in recent editions, Class 4 for low-consequence services.
• Intervals. Thickness measurement at the shorter of half the remaining life or the class maximum. OSHA's refinery mechanical integrity guidance, citing API 570, gives five years for Class 1 and ten years for Classes 2 and 3. The 1998 edition set three years for injection points; check the current edition. Confirm the values your AI applies before dates are set.
• Special locations. Injection and mix points, deadlegs, small-bore connections, insulated lines in the CUI temperature range and soil-to-air interfaces receive extra CMLs and specific methods.
• Corrosion rates. Long-term and short-term rates come from CML history, and the inspector normally governs on the more conservative one.

Atlantis can calculate corrosion rates and remaining life from its thickness data for the AI's review; the interval decision is the AI's and the owner's. Background: API 570 code requirements, what triggers an internal piping inspection and API 510 vs API 570.

Naphthenic acid, ammonia and storm surge: the Mississippi damage picture

Direct answer: Mississippi programmes combine the full refinery mechanism list at Pascagoula with specialised mechanisms elsewhere: naphthenic acid corrosion in hot specialty-refinery circuits, ammonia and nitric acid service at Yazoo City, chlorine chemistry on the coast and cryogenic stainless at the LNG terminal. Externally, coastal humidity and flooding make CUI and support corrosion constant themes.

Refinery internal mechanisms. At a large, complex refinery the API 571 list commonly includes sulfidation in hot circuits, high-temperature hydrogen attack screening for hydroprocessing equipment, ammonium bisulfide and chloride corrosion in effluent piping, wet H2S damage in sour water and amine service, and erosion in coker and slurry lines. Injection points for wash water and inhibitors need dense grids or mapping rather than single spot readings.

Naphthenic acid in hot circuits. Naphthenic acid attack is localised and velocity-sensitive, so it appears at elbows, reducers, pump discharges and weld roots rather than as even wall loss. Corrosion mapping at fittings, combined with thickness readings placed where flow turns, gives the AI a far better picture than a single reading per CML.

Ammonia and nitrogen services. Carbon steel in anhydrous ammonia can suffer stress corrosion cracking under some conditions, and stainless in nitric acid service depends on correct material and welding. Weld examination by WFMT, PT or PAUT, chosen by the AI's damage mechanism list, sits alongside thickness work.

CUI and coastal flooding. High humidity and heavy rainfall soak damaged insulation, and the 2005 Katrina storm surge showed how far salt water can reach into coastal plants. After a flooding event, lines that were submerged often need targeted external inspection. Our API RP 583 CUI guide and API 571 damage mechanisms guide give the background.

NDE methods for API 570 work in Mississippi

Direct answer: UT thickness at CMLs carries the programme; corrosion mapping covers injection points and naphthenic-acid-prone fittings; profile RT covers insulated and small-bore lines; guided-wave screening covers long terminal and dock runs; PAUT, TOFD, MT and PT cover welds in cracking services; and VT covers every external inspection.

Mississippi has been an NRC Agreement State since 1962, and the Mississippi State Department of Health's Division of Radiological Health licenses industrial radiography. RT on Mississippi sites is performed only by crews licensed for work in Mississippi; we confirm licensing and exclusion zones during scoping, and offer PAUT where radiography would disrupt a busy unit.

How Atlantis supports your Authorized Inspector

Direct answer: We deliver the NDE in the AI's plan: Level III-reviewed procedures, examinations by technicians certified to an ASNT SNT-TC-1A written practice, data checked against history on site, and a digital report organised by circuit and CML. We are not an Authorized Inspection Agency and we do not supply API-certified inspectors.

1. Scope from the plan. Circuits, isometrics, CMLs, damage mechanisms, methods and coverage come from the AI's inspection plan.
2. Procedures. An ASNT NDT Level III prepares or reviews each technique, including high-temperature UT for hot specialty-refinery circuits and profile RT through insulation.
3. Fieldwork. Crews are mobilised to your site; the schedule is agreed during scoping around permits, unit status and weather.
4. Data QA. Readings are compared with the previous survey before the crew leaves; unexpected loss and mismatched IDs are re-shot or flagged.
5. Report. CML readings, C-scans, radiographs, guided-wave results with follow-up, calibration records and technician certifications in our digital reporting platform.
6. AI evaluation and sign-off. The AI reviews rates, remaining life and next dates, decides on repairs and signs.
7. Next interval. The same CML identifiers and reading patterns carry forward.

At a refinery with its own inspection department, that usually means extra certified hands for a survey or a turnaround peak; at a smaller plant, it means a complete NDE package the AI can evaluate without chasing missing data. RBI and fitness-for-service assessments are performed by the owner's engineers or specialists using our data; Atlantis does not offer them. See API 570 piping NDE support and piping circuit and CML inspection.

Mississippi regulations that sit on top of API 570

Direct answer: Federal OSHA enforces process safety management in Mississippi, which has no State Plan for private employers, and EPA Region 4 enforces the Risk Management Program. PHMSA regulates hazardous-liquid pipelines in the state directly, the Mississippi Public Service Commission covers intrastate gas pipelines, and PHMSA's LNG rule applies to the regulated parts of the LNG terminal. Confirm current requirements with each agency.

OSHA PSM and EPA RMP

Under 29 CFR 1910.119(j), covered processes need written mechanical integrity procedures, inspection and testing of piping following recognised and generally accepted good engineering practices, documented results and timely correction of deficiencies. API 570 is the practice most owners cite. OSHA's refinery guidance also expects anomalous thickness readings to be investigated and retested rather than ignored, which is why on-site data QA matters. The Pascagoula refinery, the Yazoo City fertilizer plant, gas plants and many chemical plants hold covered processes, and EPA's RMP rule at 40 CFR Part 68 carries a parallel mechanical integrity element for Program 3 processes.

Pipelines: PHMSA, the Public Service Commission and LNG

PHMSA's Office of Pipeline Safety inspects and enforces the rules for both interstate and intrastate hazardous-liquid pipelines in Mississippi, while the Pipeline Safety Division of the Mississippi Public Service Commission handles intrastate natural gas systems under PHMSA certification. The hazardous-liquid rule (49 CFR Part 195) and gas rule (Part 192) govern regulated pipelines, including the Collins delivery systems and gas storage pipelines; plant and terminal piping inside the fence generally stays under API 570 and PSM, and the operator documents the boundary at launchers, receivers, meters or the first isolation valve. The regulated portions of LNG facilities fall under 49 CFR Part 193. Pipeline-side NDE is on our pipeline inspection page.

MDEQ, boilers and vessels

The Mississippi Department of Environmental Quality issues air and water permits for the major plants, and leak detection and repair conditions in air permits make piping leaks an environmental compliance issue too. The Mississippi State Department of Health's Boiler and Pressure Vessel Safety Branch covers boilers and pressure vessels, not process piping. Vessel and tank outages usually share windows and scaffolding with piping work, so plan them together; see API 510 pressure vessel inspection in Mississippi and API 653 tank inspection in Mississippi.

Planning around turnarounds, storms and rain

Direct answer: Run on-stream CML surveys, mapping and guided-wave screening year-round; plan insulation stripping and CUI campaigns outside the peak of hurricane season; book turnaround NDE well ahead because Gulf Coast turnaround seasons overlap; and allow for heavy rain and summer heat.

• Hurricane season, June to November: coastal owners avoid leaving insulation stripped or lines open in the peak months, and keep a post-storm walkdown plan. Atlantis can collect post-storm and post-flood data once the site is safe.
• Turnaround seasons: spring and autumn turnarounds along the Gulf Coast compete for the same NDE technicians. Agreeing scope early, with on-stream UT done beforehand, protects the critical path.
• Year-round on-stream work: CML surveys, injection-point mapping, profile RT on hot or insulated lines and screening of long runs.
• Pipeline hub rotation: at Collins, terminal piping work follows pipeline batch schedules and the operator's tank rotation.
• Heat and rain: early starts, shade and temperature-corrected readings in summer; drainage and access planning in wet months.

Book a scoping call to fit the work into your turnaround or rotation.

API 570 piping inspection support across Mississippi

Direct answer: Atlantis supports API 570 programmes statewide, from Pascagoula and the coast to Vicksburg, Yazoo City and the Pine Belt. Crews are mobilised to your site and the schedule is agreed during scoping.

• Pascagoula and Jackson County: refinery, LNG terminal and Bayou Casotte chemical piping.
• Gulfport, Biloxi and DeLisle: chemical, terminal and port piping on the coast.
• Vicksburg and the river: specialty refinery, asphalt and river-terminal piping.
• Laurel, Sandersville, Collins and Hattiesburg: refinery, pipeline terminal, gas storage and gas-processing piping.
• Yazoo City and the Delta: ammonia and nitrogen fertilizer piping.
• Jackson and the north: industrial, pulp and paper and utility piping.

Statewide services are on NDT inspection services in Mississippi; Level III support is on NDT consulting in Mississippi; and for technician development see ASNT NDT training in Mississippi and NDT training in Pascagoula.

Keeping piping history usable

Direct answer: Corrosion rates depend on comparable readings. We keep your circuit and CML numbering, record the reading pattern, instrument and calibration for each CML, and deliver data that loads into your inspection database, with optional digital twin and ERP views.

Large sites often hold readings from several contractors and several software systems. When a reading pattern or location differs from history, we flag it rather than let it produce a misleading rate, and new CMLs are photographed and described for the next crew. Results can be viewed in a digital twin of the unit, and certificates, calibrations and work orders can be tracked in our inspection-management ERP. Layouts are on NDT report templates; construction-code background is in ASME B31.3 explained.

What to send us for a Mississippi quote

Direct answer: Send the circuit list and isometrics, the last API 570 report, the AI's plan, insulation and access details and your dates. We reply with questions or a scope, and a quote within 24 hours of having what we need.

1. Circuit list with service class, material, size, schedule, temperature and pressure.
2. Isometrics with CMLs, injection points, deadlegs, small-bore connections and insulated or traced sections marked.
3. The last API 570 report and thickness history, or confirmation that this is a baseline.
4. The AI's plan and damage mechanisms, including naphthenic acid, ammonia, chlorine or cryogenic services.
5. Which lines connect to PHMSA- or PSC-regulated pipelines, and where the boundary is documented.
6. Access, scaffolding, insulation removal, permits, site orientation and dates.

Send us your circuit list and we will scope the NDE against your AI's plan.

Frequently asked questions: API 570 in Mississippi

Who performs API 570 piping inspection in Mississippi?

The owner's API 570 authorized piping inspector, employed by the owner or an inspection agency, directs the inspection, evaluates the results and signs. Qualified examiners take the measurements. Atlantis performs that NDE and delivers documented results to your AI, who remains inspector of record.

Is API 570 required by law in Mississippi?

Not by name. OSHA PSM requires covered processes to inspect piping following recognised good engineering practice, which for most owners is API 570, and EPA's RMP has a parallel requirement. Confirm your obligations with OSHA, EPA Region 4 and your programme documents.

How often does refinery piping need inspection under API 570?

Thickness at the shorter of half the remaining life or the class maximum; OSHA guidance citing API 570 gives five years for Class 1 and ten for Classes 2 and 3. A qualifying RBI programme can set intervals instead. Your AI sets the dates.

Who regulates pipelines in Mississippi?

PHMSA directly regulates interstate and intrastate hazardous-liquid pipelines; the Mississippi Public Service Commission inspects intrastate gas pipelines under PHMSA certification. Piping inside a plant or terminal fence stays under API 570 and PSM.

How do you inspect for naphthenic acid corrosion?

Following the AI's plan, we use corrosion mapping and dense UT grids at elbows, reducers, pump discharges and other high-velocity points in hot circuits, because the attack is localised. Single spot readings can miss it.

Do you inspect ammonia piping at fertilizer plants?

Yes. We perform the thickness and weld examinations the AI's plan calls for, including MT or WFMT and PAUT on carbon steel welds where stress corrosion cracking is a listed mechanism.

Is Atlantis an Authorized Inspector?

No. We are not an Authorized Inspection Agency and we do not supply API-certified inspectors. That keeps our NDE independent of the evaluation your AI makes.

Who licenses industrial radiography in Mississippi?

The Mississippi State Department of Health's Division of Radiological Health, under the state's NRC Agreement State programme. RT is performed only by crews licensed for work in Mississippi.

What certifications do your technicians hold?

Certification to an ASNT SNT-TC-1A written practice for each method, with Level III-reviewed procedures. Certificates and calibration records come with every report.

Do you provide RBI, fitness-for-service or API 570 training?

No. RBI and FFS are performed by the owner's engineers or specialists using our data, and we train only to ASNT SNT-TC-1A. See the API inspector career guide and ASNT Level III training.

How quickly can you mobilise to Pascagoula or Vicksburg?

We quote within 24 hours of receiving the scope information. Mobilisation is agreed during scoping around permits, turnaround dates and weather.

Next step

For CMLs coming due, naphthenic acid mapping, post-storm checks or turnaround weld NDE, get a quote within 24 hours. Atlantis performs the NDE; your API 570 Authorized Inspector remains inspector of record and signs the inspection report.

More Atlantis NDT services in Mississippi

• NDT training and certification in Mississippi
• Level III consulting in Mississippi
• NDT inspection services in Mississippi
• API 653 storage tank inspection support in Mississippi
• API 510 pressure vessel inspection support in Mississippi
• Practical NDT simulator in Mississippi

Part of the wider piping circuit inspection service at Atlantis NDT.