API 510 Pressure Vessel Inspector Practice Questions — 10 Free (2026)

When the preheat method is used as an alternative to postweld heat treatment for a repair, what minimum preheat temperature must be maintained during welding?

• A. 400 deg F
• B. 200 deg F
• C. 300 deg F ✓
• D. 600 deg F
• E. A temperature determined by the inspector

The alternative is available for defined P-number groups only, and the elevated preheat must be maintained throughout the welding operation. API 510, 8.6

According to API 577, who is responsible for developing the "written practice" for NDE personnel qualification?

• A. The API Committee
• B. The ASME Board
• C. The Employer ✓
• D. The Welder
• E. The local government

Both SNT-TC-1A and CP-189 require the employer to establish a written practice detailing training, experience, and certification requirements. API 577, 9.6.1

A Type B sleeve is fitted at a defective girth weld so that axial reinforcement is provided. Which loads must its design carry?

• A. Torsional loads only
• B. Internal pressure only
• C. Axial and bending loads ✓
• D. Only the weight of the pipe
• E. Thermal expansion loads only

If providing axial reinforcement at a defective girth weld, the sleeve must be designed for axial and bending loads. ASME_PCC2, Article 206-3.2

According to T-277.1(b), what must be placed adjacent to an IQI if it is located on the film side?

• A. A lead letter "B"
• B. A lead letter "F" ✓
• C. The manufacturer's logo
• D. A date stamp
• E. A serial number

When inaccessibility requires film-side IQI placement, a lead letter "F" must be used as a mandatory indicator. ASME Section V T-277.1(b)

What safety margin in temperature is applied when using Nelson curves?

• A. 10–20 °F
• B. 75–100 °F
• C. 25–50 °F ✓
• D. 100–200 °F
• E. None of the above

API guidance recommends applying a safety margin of 25°F to 50°F when using Nelson curves for design or evaluation. API 571, Section 3.36.6

When establishing fixed intervals, a remaining life (RL) evaluation is mandatory to ensure:

• A. The vessel can operate safely until the next scheduled inspection ✓
• B. The corrosion rate used for the vessel stays constant over its life
• C. The vessel will not need a pressure test at the next inspection
• D. The inspection interval can be extended beyond 10 years
• E. The next inspection can be done on-stream instead of internally

A fixed interval is only valid if the remaining life, worked out from the measured corrosion rate and the required thickness, runs past the next scheduled inspection. That is why API 510 caps the interval at half the remaining life or 10 years, whichever is less. The evaluation does not freeze the corrosion rate, remove the need for a pressure test or decide between on-stream and internal inspection. API 572, 8.2

A carbon steel vessel is marked with an MDMT of -20 deg F and the coincident ratio was not applied. What minimum metal temperature applies during a pneumatic test?

• A. -20 deg F
• B. 10 deg F ✓
• C. 30 deg F
• D. 40 deg F
• E. -50 deg F

The 30 deg F figure is an increment on the MDMT, not an absolute temperature, which is the second distractor. Note that the margin is mandatory for a pneumatic test but recommended for a hydrostatic test, where the metal shall still never be colder than the MDMT. ASME BPVC VIII-1, UG-100(c)

A vessel has a calculated remaining life of 2.6 years and no RBI assessment has been performed. What is the maximum internal or on-stream inspection interval that may be set?

• A. 2.6 years
• B. 2.0 years ✓
• C. 1.30 years
• D. 4.0 years
• E. 10.0 years

Below 4 years the code allows the full remaining life rather than half of it, but caps the interval at 2 years. Applying the ordinary half-life rule is the main distractor. API 510, 6.5.1

In-service welding is to be performed onto a carbon steel component with a wall thickness of 0.219 in. What does ASME PCC-2 indicate regarding electrode selection?

• A. Smaller diameter electrodes, on the order of 0.094 in., should be used ✓
• B. No special electrode restriction applies at wall thicknesses above 0.188 in.
• C. Welding onto a wall of this thickness while in service is prohibited
• D. Only electrodes of 0.188 in. diameter or larger may be used for this wall
• E. Cellulosic electrodes should be selected to reduce the heat input to the wall

Thin walls are welded in service by controlling heat input and penetration rather than by prohibition. Low hydrogen consumables are the correct choice for the separate hydrogen cracking concern. ASME PCC-2, Article 210

Visible colour contrast magnetic particles are used and indications are evaluated under white light. What minimum light intensity is required at the examination surface?

• A. 50 fc (538 lx)
• B. 100 fc (1 076 lx) ✓
• C. 500 lx
• D. 2 fc (21.5 lx)
• E. 1,000 microwatt per sq cm

The last distractor quotes a UV-A figure rather than a white light figure, and the 2 fc value is the maximum ambient white light permitted during fluorescent examination, which is a ceiling rather than a floor. ASME BPVC V, T-777.1