This 2026 practice exam bank prepares candidates for the API 570 Piping Inspector certification. The questions reflect the API 570 Body of Knowledge (BOK) and reference API 570 Piping Inspection Code (In-service Inspection, Rating, Repair, and Alteration), API RP 574 (Inspection Practices for Piping System Components), API RP 577 (Welding Inspection and Metallurgy), API RP 578 (Material Verification Program), API RP 576 (Pressure-Relieving Devices), ASME PCC-2, API 571 (Damage Mechanisms), ASME B31.3 (Process Piping), and ASME B16.5, BPVC V and IX.
\nFrom the API 570 program page on api.org (check it before you book; details change by exam window):
\nCorrect Answer: A
Explanation: API 570's recommended maximum inspection interval table gives visual external intervals of 5 years for Class 1, 5 years for Class 2, 10 years for Class 3, and optional for Class 4. (The half-remaining-life limit applies to thickness measurements, not external visual.) Class definitions depend on consequence (toxic/flammable/etc.).
Correct Answer: A
Explanation: API 570 classifies piping by consequence: Class 1 highest (flashing flammables, HF, H2S above 3%, anhydrous HCl), Class 2 (most flammables, on-site steam, acids/caustics), Class 3 (flammables that do not vaporize, non-toxic), Class 4 (water, plant air).
Correct Answer: A
Explanation: ASME B31.3 Eq. 3a: t = PD / (2(SE + PY)) where P = pressure, D = OD, S = allowable stress, E = quality factor, Y = coefficient from Table 304.1.1. Add mill tolerance (typically 12.5%) and corrosion allowance for required nominal thickness.
Correct Answer: A
Explanation: Per API 570 and RP 574, TMLs concentrate at locations of expected damage: elbows (extrados & intrados), tees, reducers, dead legs, injection points, mixing points, vents/drains, and at known damage mechanism locations.
Correct Answer: A
Explanation: Injection points (e.g., corrosion inhibitor, water, antifoulant injection) experience accelerated localized corrosion downstream. API 570 treats injection points as separate circuits; the recommended upstream limit is the greater of 12 in. (300 mm) or three pipe diameters upstream, and the downstream limit is the lesser of the second change in flow direction past the injection point or 25 ft (7.6 m) beyond the first change in flow direction. Injection-point thickness measurements have a 3-year recommended maximum interval.
Correct Answer: A
Explanation: CUI is most aggressive in the temperature range where moisture can be present beneath the insulation: −12 to 175°C (carbon steel). API 570 and API RP 583 give CUI risk-based inspection guidance. Stainless can suffer chloride SCC in this same range.
Correct Answer: A
Explanation: Dead legs (block valves, vent lines, dead-end caps) accumulate stagnant fluid, water, sediment, or vapor that drive localized corrosion, MIC, and freeze damage. API 570 requires identification and special inspection of dead legs.
Correct Answer: A
Explanation: Most piping cannot be entered for internal inspection. API 570 requires external NDT (UT, RT, guided wave UT, PEC, PAUT corrosion mapping) at intervals that establish integrity. Internal inspection at openings is performed where access allows.
Correct Answer: A
Explanation: HTHA per API 941 occurs in carbon and low-alloy steels exposed to hydrogen partial pressure and elevated temperature combinations that exceed Nelson curve limits. AUBT (Advanced Ultrasonic Backscatter Technique), TOFD, and metallographic replication are used to detect HTHA.
Correct Answer: A
Explanation: Positive Material Identification (PMI) uses portable XRF or OES to verify alloy composition during construction, repair, and in-service. API RP 578 prevents catastrophic failures from material mix-ups (e.g., carbon steel instead of 5Cr-1/2Mo in a hot piping system).
Correct Answer: A
Explanation: API 570 limits thickness measurement intervals to the lesser of one-half remaining life or the table maximum: 5 years for Class 1, 10 years for Class 2, 10 years for Class 3, optional for Class 4 (3 years for injection points). RBI may modify these intervals.
Correct Answer: A
Explanation: API 570 Section 4 requires the inspector to hold current API 570 certification, experience per the API ICP requirements, and operate under the owner/user’s inspection management system.
Correct Answer: A
Explanation: API 570 Section 8 requires documented repair plans, qualified WPS/PQR per ASME IX or B31.3 Chapter V, qualified welders, applicable NDT, and PWHT as required by base metal and service.
Correct Answer: A
Explanation: Bolted clamps and enclosures (e.g., engineered leak repair) are temporary repairs that must be designed, documented, and replaced with a permanent repair by the next planned turnaround per API 570 Section 8.
Correct Answer: A
Explanation: ASME B31.3 Table A-1 allowable stress S is the lowest of (UTS at T)/3, (UTS at 38°C)/3, (YS at T)/1.5, (YS at 38°C)/1.5, and creep/rupture rules. Different ratios apply for high-pressure piping (Chapter IX).
Correct Answer: A
Explanation: B16.5 Class is a pressure rating that varies with material group and temperature. For example, Class 300 carbon steel (Group 1.1) rates 740 psig at 100°F and drops to 290 psig at 850°F. Each class has a full temperature-pressure curve.
Correct Answer: A
Explanation: B31.3 paragraph 345 specifies hydrostatic test at 1.5 × design pressure adjusted for temperature ratio, or pneumatic at 1.1 × design with hazard considerations. Sensitive leak testing is allowed under specific conditions.
Correct Answer: A
Explanation: NAC affects crude distillation and vacuum unit piping when TAN exceeds 0.5 mg KOH/g, in the 220 to 400°C window, with high velocity/turbulence. 316/317 stainless or 5Cr-1/2Mo with selective upgrade are typical remedies.
Correct Answer: A
Explanation: Inspectors should record damaged or missing pipe supports during external inspection. Loss of support shifts loads to remaining supports, creates fatigue, and may cause excessive stress in nozzles and flanges.
Correct Answer: A
Explanation: The soil-to-air interface (generally considered to run from 12 in. below to 6 in. above the soil surface) experiences accelerated external corrosion. API 570 requires these zones to be inspected, including excavation or coating removal where indicated.
Correct Answer: A
Explanation: MIC by sulfate-reducing bacteria (SRB) and other microbes accelerates pitting and weld metal corrosion. Common in firewater piping, intermittent service lines, and hydrotest water left in pipe. API 571 documents MIC mechanisms and inspection.
Correct Answer: A
Explanation: GWUT sends low-frequency (20 to 100 kHz) torsional/longitudinal waves along the pipe wall. It detects cross-sectional area changes (typically >5%) up to 30 to 50 m on insulated, buried, or elevated pipe. It is a screening tool, not a sizing tool.
Correct Answer: A
Explanation: PEC pulses a magnetic field through insulation/weather jacket and measures the decay to estimate average wall thickness. It is a screening tool for CUI — not absolute thickness. Spot UT after PEC indications is standard practice.
Correct Answer: A
Explanation: Piping is grouped into inspection circuits by service, material, expected damage mechanism, and operating conditions. Each circuit has a defined set of TMLs and inspection records. API RP 574 provides circuit definition guidance.
Correct Answer: A
Explanation: ASME B31.3 paragraph 304.3 requires branch reinforcement calculation. If header thickness in excess of pressure-design accounts for the removed material, no extra reinforcement is needed; otherwise, pads, weldolets, or wall thickness must compensate.
Correct Answer: A
Explanation: Most flange leaks are gasket seating issues. Proper bolt torque (per ASME PCC-1), gasket selection (compatible with service), and avoiding flange face damage are key. Hot-bolting (re-tightening at operating temperature) is sometimes needed.
Correct Answer: A
Explanation: Mill tolerance on seamless pipe is 12.5% under nominal. A 10 mm nominal pipe could be as thin as 8.75 mm new. 9.5 mm is normal new-pipe variation; corrosion is not implied unless previous baseline was higher.
Correct Answer: A
Explanation: API 570 places the program responsibility with the owner/user, who classifies piping, sets inspection intervals, employs authorized inspectors and engineers, and maintains records. The inspector verifies code compliance.
Correct Answer: A
Explanation: Carbon steel below MDMT (often around −29°C for non-impact-tested A106) loses toughness and may fail brittlely when pressurized. Cold blowdowns and autorefrigeration upsets must be analyzed and limited.
Correct Answer: A
Explanation: An API 570 inspector commands a broad NDT toolbox: visual, thickness UT, shear wave UT (for cracks), profile RT, PT, MT, PAUT, TOFD, GWUT, PEC, MFL, eddy current array. The inspector selects techniques based on the damage mechanism — not the other way around.
A: API 570 covers in-service piping inspection; API 510 covers in-service pressure vessels. See our API 510 vs 570 comparison.
\nA: Yes — the API ICP certifications are independent. Many inspectors take API 510 first (more vessel work) but API 570 first is fine.
\nA: 3 years. Recertification needs at least 20% of working time on inspection activities and 24 CPD hours each cycle, plus an online web quiz every 6 years.
\nA: The highest consequence category — toxic, flammable that vaporizes on release, HF acid, H2S above 3%. Class 1 has the shortest inspection intervals.
\nA: API 570 references API RP 2201 for hot tapping procedures. Pre-tap NDT, qualified hot tap WPS, and burn-through prevention are required.
\nA: No. Atlantis NDT does not run API 570 exam-preparation courses. Our API 570 piping inspection support is ASNT Level III technical work on piping programmes, not exam coaching.
\nA: Yes — widely recognized by Aramco, ADNOC, KOC, QatarEnergy, Reliance, Indian Oil, BPCL, and most major refineries.
\nA: API publishes exam statistics in its ICP status updates. The April 2024 update reported per-window pass rates for API 510, 570 and 653 ranging from roughly 45% to 72% between 2018 and early 2024, with a scaled pass point of 400. Check the latest API ICP statistics report rather than relying on third-party estimates.
\nA: Pay varies widely by region, employer, rotation and overtime. For US figures use attributed sources such as the Bureau of Labor Statistics or the ASNT salary survey; see our NDT inspector salary guide.
\nA: CSWIP 3.1 is a welding inspection certification commonly used in welding fabrication QC. API 570 is in-service piping inspection. Many inspectors hold both for complete fabrication-to-service coverage.
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