API 510 Pressure Vessel Inspection Support in Washington

Short answer: In Washington, unfired pressure vessels that are not exempt carry a state inspection certificate from the Department of Labor and Industries (L&I) Boiler Program, with external inspections every two years and internal inspections every two years where the vessel is subject to corrosion. National Board certified owner/user organizations, which is how most refineries operate, may inspect to API 510 instead. The owner's API 510 Authorized Inspector (AI) runs that programme. Atlantis NDT performs the nondestructive examinations behind it: UT thickness at CMLs, corrosion mapping, PAUT, TOFD, WFMT, ET, RT, PT and VT. Atlantis performs the NDE; your API 510 Authorized Inspector remains inspector of record and signs the inspection report.

Washington is unusual in three ways that shape vessel work here. Its refining is concentrated in two small clusters on the north Puget Sound shoreline that run on Alaska North Slope and Canadian crude rather than pipeline crude from the Gulf. Since December 2024, its refineries have worked under a refinery-specific process safety rule, Part B of chapter 296-67 WAC, that goes further than the federal PSM standard. And its pulp and paper industry is big enough that L&I recognises a paper-industry inspection guideline alongside API 510 and the NBIC. To get started, request an NDE scope for your AI's plan.

Where API 510 pressure vessels are in Washington

Direct answer: Most of Washington's API 510 population sits in five refineries: two at Cherry Point and Ferndale in Whatcom County, two on March Point at Anacortes in Skagit County, and one on the Tacoma tideflats. Pulp and paper mills, the Tacoma LNG plant, Columbia Basin food and agricultural processing, power stations and aerospace plants add the rest.

Whatcom County: Cherry Point and Ferndale

BP's Cherry Point refinery is the largest in the state, and Phillips 66's Ferndale refinery sits a few miles south on the same stretch of shoreline. Between them they run crude and vacuum units, catalytic crackers, hydrocrackers and hydrotreaters, reformers, alkylation, coking at Cherry Point, hydrogen production and sulfur recovery. That mix gives the full refinery list of API 571 damage mechanisms: sulfidation and high-temperature hydrogen attack considerations in hydroprocessing, wet H2S damage and amine cracking in gas treating, ammonium bisulfide corrosion in reactor effluent air coolers and separators, and HF or sulfuric acid corrosion in alkylation depending on the technology. Marine-air exposure on the bluff means external corrosion and corrosion under insulation are never far behind.

Skagit County: March Point, Anacortes

HF Sinclair's Puget Sound refinery and the Marathon Anacortes refinery share March Point. Both are long-established plants with heavy-wall reactors, fractionators, drums and exchangers that have decades of thickness history, which is exactly where consistent CML numbering and like-for-like NDE matter most. A salt-water peninsula, frequent rain and cool temperatures make CUI on insulated vessels and external corrosion at supports and nozzles routine findings. See also refining NDT consulting in Anacortes.

Tacoma tideflats and south Puget Sound

The Par Pacific refinery on the Tacoma tideflats is the smallest of the five and supplies fuels including jet fuel to the south Sound. The tideflats also hold Puget Sound Energy's Tacoma LNG facility, chemical and fuel terminals, and port industry. LNG introduces cryogenic vessels, pretreatment absorbers and amine contactors, and heavy-wall receivers, where the inspection plan has to account for the outer jacket, insulation and low-temperature service. Further south, Olympia-area and Lewis County industry adds compressed-air and process vessels. See NDT consulting in Tacoma.

Pulp and paper: Longview, Camas, Wallula and the coast

Washington's kraft and paper mills along the lower Columbia River, in southwest Washington and on the Olympic Peninsula run digesters, black-liquor evaporators, recovery-boiler auxiliaries, white-liquor and green-liquor clarifier pressure equipment, bleach-plant reactors, blow tanks, accumulators and steam-heated paper machine dryer cans. Caustic cracking, sulfide and thiosulfate corrosion, erosion-corrosion and dryer-can thinning are the typical concerns. Washington's rules allow pulp and paper manufacturers to use TAPPI TIP 0402-16 for paper machine dryers when requested and approved by the chief inspector, so the dryer inspection basis may differ from the rest of the vessel population.

Columbia Basin, Spokane and eastern Washington

Food processing, cold storage and ammonia refrigeration around Yakima, the Tri-Cities, Moses Lake and Spokane bring ammonia receivers and accumulators. Data centres, battery-material and silicon plants around Moses Lake add process vessels and compressed gas systems. Federal facilities such as the Hanford Site fall under federal regulation and outside the state boiler law, so their programmes follow their own rules.

Aerospace and manufacturing around Everett, Renton and Seattle

Aircraft and component plants run autoclaves for composite curing, air receivers, nitrogen systems and process vessels. Autoclaves see pressure and thermal cycling and quick-actuating closures, so the inspection plan typically focuses on door locking mechanisms, closure welds and fatigue-sensitive details. Our pressure vessel inspection page for Seattle covers this work.

What API 510 requires, in plain terms

Direct answer: API 510 covers in-service inspection, repair, alteration and rerating of pressure vessels and their pressure-relief devices. Each vessel needs an inspection plan; external and internal or on-stream inspections are scheduled from measured corrosion rates and remaining life; and the AI accepts results and authorises repairs. In Washington, this applies through the owner/user route in the state rules.

API 510 is published by the American Petroleum Institute; the current edition is the 11th (October 2022). Public copies of older editions circulate widely, so confirm requirements against the edition your programme uses. In paraphrase, the code sets external inspection at no more than the lesser of five years or the internal or on-stream interval, and internal or on-stream inspection at no more than the lesser of half the remaining life or ten years. Where remaining life is under four years, the interval may be the full remaining life up to two years. An RBI programme that meets the code's conditions may set different intervals, and that assessment is done by the owner's engineers or a specialist, not by Atlantis.

The working document is the inspection plan. For each vessel it names the credible damage mechanisms (API 571 is the reference), the inspection type and coverage, the condition monitoring locations (CMLs), the NDE technique and the next due date. On-stream inspection can substitute for internal inspection when the code's conditions are met, which in practice means the external NDE can actually detect and size the damage the plan expects. Corrosion rates come from thickness trends at the CMLs; remaining life is the margin between measured and required thickness divided by the governing rate.

Pressure-relief devices sit inside the same programme. API 510 requires the owner to inspect and test them at intervals tied to service, with API RP 576 as the reference practice, and in Washington repair and resealing of safety devices requires the appropriate National Board certificate of authorization. Repairs and alterations to the pressure boundary follow API 510's own provisions together with the NBIC, and Washington adds its own condition: only organisations with a National Board "R" certificate may perform them, documented on "R" forms. For the arithmetic see API 510 interval calculation explained, and for code background, the API 510 code overview.

NDE methods for API 510 work in Washington

Direct answer: UT thickness and automated corrosion mapping provide the trend data; PAUT, TOFD and WFMT address cracking in hydroprocessing, amine, sour-water and caustic services; ET covers exchanger tubes; RT, PT and VT cover welds, stainless equipment and overall condition. In Washington's climate, CUI screening of insulated vessels is a standing item on almost every plan.

Coverage is as important as technique. We document scan areas, grid density, the damage mechanism each technique targets and any locations that could not be examined, so the AI can judge whether an on-stream examination genuinely substitutes for an internal one. Insulated vessels near salt water are prime CUI candidates; see CUI inspection support, and for mechanism background, our API 571 damage mechanisms guide.

Radiography in Washington is licensed by the state: Washington is an NRC Agreement State, and the Department of Health's Office of Radiation Protection licenses and inspects industrial radiography. RT on Washington sites is performed by crews licensed for work in the state.

How Atlantis supports your Authorized Inspector

Direct answer: Atlantis converts the AI's inspection plan into Level III-reviewed procedures, performs the examinations with ASNT-certified technicians and delivers a digital report the AI evaluates and signs. We are not an Authorized Inspection Agency and we do not supply API-certified inspectors. That separation keeps the NDE data independent of the inspection judgement.

In Washington the inspector of record is usually one of two people. At refineries and large chemical or mill sites, it is the owner's API 510 inspector working inside a National Board certified owner/user organization. At smaller sites, the state certificate inspection is done by an insurance company's special inspector commissioned by L&I, or by an L&I inspector. Atlantis works underneath either as the NDE contractor:

1. Plan intake. Vessel list, CML map, damage mechanisms, inspection type and due dates from the AI's plan, plus certificate expiry dates so one campaign serves both the API 510 schedule and the state certificate.
2. Procedures. UT, mapping, PAUT, TOFD, WFMT, ET and RT techniques prepared or reviewed by an ASNT NDT Level III, with coverage plans where on-stream inspection is proposed in place of entry.
3. Field execution. Crews mobilised to your site; the schedule is agreed during scoping around unit status, permits, confined-space entry and weather.
4. Data QA. Readings checked against history before demobilisation; anomalies re-shot while scaffolding and insulation removal are still in place.
5. Digital report. CML IDs, readings, C-scans, indication tables, photographs, calibration and equipment records and technician certifications in Atlantis's reporting platform.
6. Evaluation and sign-off. The AI determines corrosion rates, remaining life, intervals and repairs. Corrosion-rate and remaining-life figures can be calculated from our data for the AI's review, but the decision is the AI's and the owner's. Atlantis performs the NDE; your API 510 Authorized Inspector remains inspector of record and signs the inspection report.
7. Next cycle. CML numbering carries forward unchanged, so the next survey trends like for like.

Where the owner's engineers run RBI or a fitness-for-service assessment, our maps and flaw sizes feed work done by them or a specialist. More: API 510 pressure vessel NDE support and pressure vessel inspection services.

Washington regulations that sit on top of API 510

Direct answer: L&I's Boiler Program enforces chapter 70.79 RCW and chapter 296-104 WAC: certificates of inspection, two-year internal and external intervals for unfired vessels subject to corrosion, the NBIC as the inspection standard, API 510 for certified owner/users and mandatory "R" certificates for repairs. L&I's DOSH enforces process safety, including the refinery-specific Part B of chapter 296-67 WAC. Confirm details with L&I.

Boiler and unfired pressure vessel law. Washington's Board of Boiler Rules adopts the rules, and the chief boiler inspector at L&I administers them. The state adopts the NBIC Parts 1 to 4 as its inspection, repair and pressure-relief standards. According to the National Board's jurisdictional synopsis (reviewed by the state in 2025), unfired pressure vessels receive an external inspection every two years and an internal inspection every two years when subject to corrosion, and the certificate of inspection for pressure vessels is valid for no more than 26 months. National Board certified owner/user organizations may choose to use the current edition of API 510 instead. Exemptions include, among others, vessels under federal regulation, vessels designed for 15 psi or less, small vessels below the volume and diameter limits in the rules, vessels containing liquefied petroleum gases (exempt from inspection and fees), and vessels in cities that enforce equal or stricter ordinances. Check the current rule text for your equipment.

Who inspects. L&I inspectors, special inspectors employed by insurance companies and commissioned by the department, and inspectors of certified owner/user organizations. Insurers must notify L&I when risks are written, cancelled or suspended for unsafe conditions, and a certificate on an insured vessel lapses when insurance ends. Inspection reports are filed with the department within 30 days.

Repairs and alterations. Only organisations holding a National Board "R" certificate of authorization may repair or alter the pressure boundary in Washington, on "R" forms with a completed traveler. NDE of repair welds, whether RT, UT, PT or MT, is part of the repair package the "R" holder and the inspector review; Atlantis can perform that NDE for the repair organisation or the owner but does not hold or use an "R" stamp.

Process safety: DOSH and the refinery rule. Washington runs its own OSHA state plan through L&I's Division of Occupational Safety and Health (DOSH). Chapter 296-67 WAC carries the process safety management standard, and L&I adopted a new Part B for petroleum refineries in December 2023, effective December 27, 2024. Part B keeps the mechanical integrity element and adds refinery-specific requirements built on lessons learned since the original PSM rule, including a documented damage mechanism hazard review as part of the process hazard analysis cycle and a hierarchy of hazard controls analysis. For vessel inspection that means refineries need a damage mechanism basis for every vessel and NDE that demonstrably addresses it. Non-refinery PSM sites remain under Part A. EPA's Risk Management Program (40 CFR Part 68) Program 3 runs in parallel.

Pipelines and the fence line. The Washington Utilities and Transportation Commission's pipeline safety programme oversees intrastate pipelines with PHMSA; interstate lines fall to PHMSA under 49 CFR Parts 192 and 195. Pig receivers and separators at the fence line should have a clearly assigned code and inspection owner.

Planning around turnarounds, weather and the certificate cycle

Direct answer: Line up certificate expiry dates with API 510 due dates, use on-stream NDE to limit the number of vessels opened, book refinery turnaround NDE early because the five refineries draw on one regional labour pool, and plan external and CUI work for the drier months.

• Two-year certificate rhythm: for vessels inspected under the state schedule rather than API 510, list each vessel's certificate expiry beside its internal and external due dates and plan one campaign to meet both.
• Refinery turnarounds: Puget Sound refineries supply most of the state's fuel, so outages are carefully staggered. Heavy-wall TOFD, reactor weld PAUT and WFMT of amine and sour water vessels should be scoped and procedures approved before the outage starts.
• On-stream first: where external NDE can see the expected damage, the AI may credit an on-stream inspection; agree technique and coverage before the outage so entries are saved for vessels that genuinely need them.
• Weather: the wet season from autumn through spring makes insulation removal and external coatings work harder; schedule CUI campaigns and external surveys for summer where possible, and plan weather protection for winter work in Whatcom and Skagit counties.
• Mill outages: pulp and paper mills run long campaigns with short annual or semi-annual shutdowns; on-stream UT of digesters and accumulators and ET of evaporator tubes are planned into those windows.
• Remote sites: eastern Washington and Olympic Peninsula sites need travel and access planning, which is agreed during scoping.

API 510 inspection support across Washington

Direct answer: Atlantis supports API 510 and state-certificate vessel programmes from Whatcom County to the Tacoma tideflats, the lower Columbia River and eastern Washington. Crews are mobilised to your site, and the schedule is agreed during scoping.

• Seattle, Everett and Renton: pressure vessel inspection in Seattle, with corrosion inspection, piping inspection, tank inspection and pipeline inspection in the Seattle area, plus ultrasonic testing in Seattle.
• Ferndale, Cherry Point and Blaine: refinery vessels, heavy-wall reactors and gas-treating equipment.
• Anacortes and March Point: refinery vessels with long thickness histories; NDT consulting in Anacortes.
• Tacoma and south Puget Sound: refinery, LNG, terminal and port vessels.
• Longview, Kelso, Camas and Vancouver: pulp, paper and chemical plants on the lower Columbia.
• Tri-Cities, Yakima, Moses Lake and Spokane: ammonia refrigeration, food processing, power and manufacturing.

Sibling hubs for the state: API 653 tank inspection in Washington and API 570 piping inspection in Washington. For all NDT methods statewide see NDT inspection services in Washington; for procedures and written practices, NDT consulting in Washington; and for in-house technicians, ASNT NDT training in Washington. Results can be viewed in 3D through a digital twin for Seattle-area assets.

Damage-mechanism reviews under the refinery rule

Direct answer: Washington's refinery PSM rule expects owners to identify credible damage mechanisms for process equipment and act on them. Atlantis does not perform the review, but it supplies the NDE evidence that shows whether a mechanism is active and whether the chosen technique can see it.

For a vessel inspection programme, a damage mechanism review produces a list of mechanisms by vessel or corrosion loop, with susceptibility and recommended inspection methods. The weak point in many programmes is not the list; it is the link between the list and what the NDE crew actually does. A mechanism such as amine stress corrosion cracking calls for WFMT on internal welds or PAUT from outside, not spot UT thickness. Ammonium bisulfide corrosion in an effluent separator calls for mapping around inlet and outlet nozzles, not a single CML per course. High-temperature hydrogen attack screening is a specialist area with its own techniques and limitations, and whether and how to screen is a decision for the owner's engineers.

Atlantis helps close that gap in a practical way. Our Level III reviews the technique against the mechanism and records coverage, detection capability and limitations in the procedure. The report then states, vessel by vessel, which mechanism each examination addressed, where data was taken and what could not be examined. That gives the AI, the PSM coordinator and the damage-mechanism review team a clean record to cite. Results can also be tracked in our inspection-management ERP, mapped onto a digital twin and delivered in formats shown on NDT report templates. For sour-service interval background see API 510 intervals in wet H2S service. Ask us to map NDE to your damage mechanism review.

What to send us for a Washington quote

Direct answer: Send the vessel list, the AI's plan and CML map, the latest API 510 or state certificate inspection reports, certificate expiry dates, access and insulation status and target dates. We quote within 24 hours of receiving that information.

1. Vessel tags, U-1 data reports or nameplate data, Washington state and National Board numbers, drawings and materials of construction.
2. The last API 510 report, the last certificate inspection report and the thickness history.
3. The AI's inspection plan, CML map and damage mechanisms of concern, including any outputs of a damage mechanism review.
4. Certificate expiry dates and whether on-stream inspection is proposed in place of internal entry.
5. Inspection type, cleaning and entry status, insulation and scaffold requirements.
6. Dates, outage window and site safety and orientation requirements.

Send us your vessel list and we will reply with questions or a draft scope.

Frequently asked questions: API 510 in Washington

Does Washington require pressure vessel inspections?

Yes, for non-exempt unfired pressure vessels. Under chapter 296-104 WAC, they need a certificate of inspection from L&I, with external inspections every two years and internal inspections every two years when subject to corrosion. Certified owner/user organizations may use API 510 intervals. Confirm current rules and exemptions with the L&I Boiler Program.

Can a Washington refinery use API 510 instead of the state's two-year intervals?

The state rules let National Board certified owner/user organizations use the current edition of API 510. Refineries normally operate that way, with intervals set by the code from corrosion rate and remaining life. The owner's AI and the organisation's programme govern; confirm the arrangement with L&I.

Who can inspect pressure vessels in Washington?

L&I inspectors, insurance-company special inspectors commissioned by L&I, and inspectors of certified owner/user organizations. API 510 inspections are signed by the owner's AI. Atlantis performs the NDE that all of them rely on.

Who can repair a pressure vessel in Washington?

Only organisations holding a National Board "R" certificate of authorization, documented on "R" forms. Atlantis can perform the repair-weld NDE for the "R" holder or the owner, but it does not perform or stamp repairs.

How often must a vessel be inspected under API 510?

Under the current edition, external inspection at no more than the lesser of five years or the internal interval, and internal or on-stream at no more than the lesser of half the remaining life or ten years, with special rules when remaining life is under four years. RBI can set different intervals.

What does Washington's refinery PSM rule change for vessel inspection?

Part B of chapter 296-67 WAC, effective December 27, 2024, applies to petroleum refineries and adds requirements such as damage mechanism review to the familiar mechanical integrity element. Vessel NDE must be traceable to the mechanisms identified. Read the rule text for exact obligations.

Is Atlantis an Authorized Inspector?

No. We are not an Authorized Inspection Agency and we do not supply API-certified or state-commissioned inspectors. We deliver independent NDE data for your AI to evaluate.

Who licenses industrial radiography in Washington?

Washington is an NRC Agreement State, so the Department of Health's Office of Radiation Protection licenses radiography. RT is performed by crews licensed for work in Washington.

Can you inspect paper machine dryers and mill vessels?

Yes. We perform UT thickness and mapping on dryer cans, digesters, accumulators and blow tanks, and ET on evaporator tubes. Washington allows TAPPI TIP 0402 for dryers when the chief inspector approves it; the inspector decides the basis.

Do you perform RBI or fitness-for-service?

No. We supply the thickness maps and flaw sizes those assessments use; the owner's engineers or a specialist perform them.

Do you offer API 510 certification training?

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

How quickly can you mobilise to Anacortes or Ferndale?

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

Next step

To line up NDE that supports your AI, your certificate cycle and your refinery or mill outage, get a quote within 24 hours or book a scoping call. Atlantis performs the NDE; your API 510 Authorized Inspector remains inspector of record and signs the inspection report.

More Atlantis NDT services in Washington

• NDT training and certification in Washington
• Level III consulting in Washington
• NDT inspection services in Washington
• API 653 storage tank inspection support in Washington
• API 570 piping inspection support in Washington
• Practical NDT simulator in Washington

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