Mixed Deck — All API 510 Topics Flashcards

When pressure testing a vessel with multiple chambers, how should the test pressure be applied?

Answer: Each chamber should be tested independently at its respective design pressure

Each pressure chamber must be tested independently at its own design test pressure to avoid over-pressuring adjacent chambers.

Why is Magnetic Particle Testing limited to ferromagnetic materials?

Answer: Only ferromagnetic materials can retain magnetic fields

Magnetic Particle Testing (MPT) is limited to ferromagnetic materials because the method relies on their ability to be magnetized and retain a magnetic field. When a magnetic field is applied to a ferromagnetic material, surface or near-surface discontinuities cause a leakage flux. Fine magnetic particles applied to the surface are attracted to these leakage fields, outlining the flaws.

When scheduling a pressure vessel inspection that requires entry, which prerequisite is mandated before an inspector enters the vessel?

Answer: Issuance of a confined space entry permit with atmospheric testing and lockout/tagout verification

Confined space entry permits require atmospheric testing for oxygen, combustibles, and toxics, along with lockout/tagout isolation of all energy sources before any person enters.

What medium is typically used in hydrostatic pressure testing?

Answer: Water

Water is the standard medium for hydrostatic testing because it is nearly incompressible, making it safer than gases if a failure occurs.

Which phase of the eddy current signal is most useful for characterizing the depth of a defect in a pressure vessel tube wall?

Answer: Phase angle, since deeper defects cause greater phase lag in the eddy current response

Phase angle in eddy current testing is used to characterize defect depth because eddy currents at greater depths experience more phase lag, allowing differentiation of ID and OD defects and depth estimation.

What types of damage mechanisms does an FFS assessment evaluate?

Answer: Various mechanisms including corrosion, cracking, creep, and mechanical damage

FFS assessments evaluate multiple damage mechanisms including general and local corrosion, cracking, creep, and mechanical damage.

Under API 510, which document authorizes a repair organization to perform repairs and alterations on ASME-coded pressure vessels?

Answer: National Board R-Stamp authorization

The National Board R-Stamp authorizes a repair organization to perform repairs and alterations on pressure vessels in accordance with the National Board Inspection Code (NBIC).

Under API 510, which entity is responsible for maintaining inspection records throughout a pressure vessel's service life?

Answer: The owner/operator

API 510 assigns responsibility for maintaining complete and current inspection records to the owner/operator of the pressure vessel.

What is the difference between general and localized corrosion?

Answer: General affects uniform areas while localized concentrates in specific spots

General corrosion causes relatively uniform thickness loss over large areas, while localized corrosion concentrates in specific spots creating deeper damage.

Which type of corrosion occurs when two dissimilar metals are in electrical contact in the presence of an electrolyte?

Answer: Galvanic corrosion

Galvanic corrosion occurs when two metals with different electrochemical potentials are in contact with each other and an electrolyte, causing the more active (anodic) metal to corrode preferentially.

A change in base metal P-number is considered what type of variable in ASME Section IX welding procedure qualification?

Answer: Essential variable

A change in base metal P-number is an essential variable requiring requalification of the welding procedure because it affects the metallurgical properties of the weld.

During phased array ultrasonic testing (PAUT) of a pressure vessel weld, what does the S-scan (sectorial scan) display show?

Answer: A cross-sectional view of the weld using multiple beam angles from a single probe position

The S-scan (sectorial scan) sweeps through multiple angles electronically, displaying a fan-shaped cross-section of the weld in a single probe placement.

A pressure vessel located in a cold climate is to be hydrostatic tested in winter. The main concern with using cold water for the test is:

Answer: Risk of brittle fracture in the vessel metal if the temperature is below the MDMT

Testing at temperatures below the vessel's MDMT increases the risk of brittle fracture, even at test pressures below the design limit.

A pressure vessel operating in wet CO₂ service develops general thinning with a pH-dependent corrosion rate. What corrosion product is responsible for the partial protective film that forms?

Answer: Iron carbonate (FeCO₃) scale, also called siderite, formed at higher pH and temperature

In wet CO₂ corrosion (sweet corrosion), iron carbonate (FeCO₃/siderite) forms at higher pH and temperatures, providing partial protection that reduces corrosion rate when the film is stable.

After completing welded repairs, what is the preferred method to verify the repair weld's integrity in a vessel that had active corrosion?

Answer: Hydrostatic test or pneumatic test per the applicable code

A pressure test (hydrostatic or pneumatic) is the preferred verification after welded repairs, confirming the repaired area can sustain the design conditions.

What is the remaining life calculation used for in FFS?

Answer: Estimating how long equipment can safely operate before reaching minimum required thickness

Remaining life calculations estimate the time until equipment reaches minimum required thickness, guiding inspection scheduling and replacement planning.

What is the term for the selective removal of one element from an alloy by corrosion, such as zinc from brass?

Answer: Dezincification

Dezincification is a form of dealloying where zinc is selectively leached from brass, leaving a porous, weakened copper-rich structure.

Under API 510, an authorized inspector must review and accept which document before repair welding begins on a pressure vessel?

Answer: The repair plan and applicable WPS/PQR

The authorized inspector must review and accept the repair plan and applicable Welding Procedure Specifications (WPS) and Procedure Qualification Records (PQR) prior to commencing repair work.

What is the significance of a Manufacturer’s Data Report?

Answer: It certifies pressure vessel compliance and specs

A Manufacturer's Data Report (MDR), often an ASME U-1A form, is a critical document that certifies a pressure vessel's compliance with the applicable construction code. It details the vessel's design specifications, materials used, fabrication methods, and inspection results. This report serves as the official record of the vessel's initial construction and is essential for future inspections and maintenance planning.

In ASME Section VIII Div. 1, what is the minimum thickness (t_min) for a flat unstayed circular head attached by welding per UG-34?

Answer: t = d × sqrt(CP / SE)

UG-34(c) gives the formula t = d × sqrt(CP/SE) for flat circular heads, where C is a coefficient based on attachment method.