Crude Distillation Unit Inspection
The crude distillation unit (CDU) represents the entry point for all crude oil into a refinery. Operating at temperatures exceeding 350°C and pressures up to 25 bar, CDU equipment endures some of the most severe service conditions found in refining. The furnace tubes carry fluid under thermal stress, experiencing brittle failure risks and creep damage over time. Fired heater inspection requires specialized radiographic examination of tube welds, combined with creep rupture damage detection techniques.
The atmospheric distillation tower itself requires periodic ultrasonic scanning for wall thinning, corrosion pitting, and localized erosion. Internal trays and support structures within the tower must be inspected through available access points. NDT consulting services experienced with CDU assessment bring knowledge of typical failure modes, remaining-life assessment methodologies, and regulatory requirements specific to atmospheric distillation operations.
Heat exchanger networks serving CDU require systematic inspection strategies. Tube-side fouling deposits obscure eddy current examination results, necessitating chemical cleaning prior to inspection. Digital twin solutions integrate inspection data with operational parameters to identify heat exchanger segments most at risk from continued operation, supporting capital investment decisions.
Hydrotreating Unit Equipment
Hydrotreating processes remove sulfur, nitrogen, and other impurities from refinery products through catalytic hydrogenation reactions. Operating under hydrogen pressure and elevated temperature, the reactors are susceptible to stress corrosion cracking in austenitic materials and hydrogen attack in ferritic steels. Periodic inspection via phased array ultrasonic testing with TOFD sizing establishes crack initiation and growth patterns, informing continued operation decisions and planned replacement schedules.
Reactor internals including catalyst support structures and product distribution systems require assessment through removable inspection plugs and access openings. Magnetic particle testing of critical welds combined with visual inspection of internal components confirms mechanical integrity. NDT training programs prepare facility personnel for systematic internal inspection procedures that maximize information gathering while minimizing turnaround duration and re-commissioning risks.
Hydrogen barrier materials and corrosion-resistant alloy cladding require specialized assessment. Ultrasonic thickness measurement through cladding layers demands methodology development and equipment calibration reflecting actual material systems. NDTConnect platform captures inspection procedures and equipment performance data for continuous improvement of NDT execution quality.
Catalytic Conversion Units
Fluid catalytic cracking (FCC) units operate at high temperatures with abrasive catalyst particles in circulation. Erosion-corrosion of process piping causes localized metal loss that may not be detected by conventional wall thickness measurements at arbitrary locations. Systematic ultrasonic scanning combined with 3D modeling identifies erosion patterns, distinguishing uniform corrosion from problematic erosion zones requiring accelerated replacement.
Catalyst circulation systems experience unique inspection challenges including complexity of dense-phase flow piping, high operating temperatures, and difficult access for conventional ultrasonic scanning. Advanced NDT techniques including guided wave ultrasonics enable rapid screening from accessible points, with follow-up detailed inspection at identified concern areas. Atlantis NDT provides specialized expertise in FCC equipment assessment developed through extensive industry experience.
Regenerator systems where catalyst is heated in air present corrosion challenges distinct from process-side equipment. Thermal stressing and oxidation accelerate degradation of ferrous materials. Periodic radiographic examination combined with remnant strength assessment informs replacement decisions that must coordinate with catalyst supply strategy to maintain uninterrupted processing capability.
Alkylation and Treating Unit Assessment
Alkylation units using hydrofluoric acid or sulfuric acid present extreme corrosiveness challenges. Specialized corrosion-resistant alloys provide necessary protection but require periodic assessment to detect localized corrosion escape failures. Ultrasonic examination demands careful methodological development reflecting actual material properties and acid exposure conditions.
Amine-based treating units for acid gas removal require monitoring for equipment degradation from amine carryover, temperature cycling, and pressure variations. Systematic inspection of amine contactors, regenerators, and downstream equipment establishes integrity baselines and predicts remaining service life. Risk-based inspection frameworks prioritize equipment with highest consequence potential, optimizing resource allocation across complex facility networks.