API 510 flashcards

33 cards. Read the term and the definition here. The deck at the top of this page is optional.

API 510 scope

Covers in-service pressure vessels, including inspection, examination, testing, rating, repair, alteration, and rerating, together with the pressure-relieving devices that protect those vessels.

Authorized inspector

An individual holding a valid API 510 certification who performs or supervises required inspections, determines intervals, and concurs with repairs, alterations, and relief device results.

Owner/user responsibility

The owner/user establishes and maintains the inspection program, designates authorized inspectors, approves repairs and alterations, and retains vessel records for the life of the vessel.

ASME R-stamp

A Certificate of Authorization held by a repair organization; it is normally required to perform code-stamped repairs and alterations on pressure vessels unless the owner/user qualifies another organization.

API 579-1/ASME FFS-1

The fitness-for-service standard referenced by API 510, used to evaluate whether components with corrosion, cracks, or other flaws can continue in service at defined operating conditions.

Construction records

Manufacturer's data report, drawings, material certifications, and heat-treatment records that the inspector reviews to establish design conditions, allowable stress, and minimum thickness.

On-stream inspection

Inspection performed while the vessel is operating, using external examinations and monitoring; it may replace internal inspection when the damage mechanisms are understood and corrosion behavior is confirmed.

Internal inspection

A documented examination of the vessel interior, usually by visual and nondestructive methods, performed periodically to detect corrosion, cracking, and other service damage.

Minimum thickness tmin

The thickness calculated with the construction code's design formulas at the original design conditions, taking the corrosion allowance as zero; measured values below it require action.

Corrosion rate formula

Corrosion rate equals metal loss, calculated as previous thickness minus current thickness, divided by the elapsed time in years between the two sets of readings.

Hydrostatic test pressure

For pressure vessels, the hydrostatic test is normally conducted at 1.3 times the MAWP, corrected for the metal temperature at test time, using water as the test medium.

Pneumatic test

Used only where hydrostatic testing is impractical; typically 1.1 times MAWP per the construction code, with enhanced exclusion zones and safety precautions because of stored energy.

External inspection

Visual examination of insulation, supports, foundations, nozzles, and accessible shell surfaces from outside the vessel, performed at intervals not exceeding five years.

Remaining life formula

Remaining life equals current measured thickness minus minimum required thickness, divided by the corrosion rate expressed in the same units per year.

Long-term corrosion rate

Metal loss from the initial or baseline thickness to the current reading, divided by total years in service; used to project long-term future metal loss.

Short-term corrosion rate

Metal loss between the last two thickness surveys divided by the interval between them; it reflects recent operating conditions and process changes.

Maximum inspection interval

For internal or on-stream inspection, the lesser of one-half the calculated remaining life or ten years, unless a risk-based inspection program establishes the interval.

Governing corrosion rate

When long-term and short-term rates differ, remaining life is calculated using both, and the shorter result governs the inspection interval until the cause is resolved.

Short remaining life

A calculated remaining life of only a few years indicates the vessel is approaching retirement, so inspection intervals shorten and repair, rerating, or replacement must be planned.

Risk-based inspection

Inspection planning per API 580 and 581 that sets intervals from the probability and consequence of failure rather than from the half-life rule alone.

Thickness measurement locations

Pre-established points on a vessel where ultrasonic readings are taken each survey so that results are comparable and corrosion rates can be calculated reliably.

PRV set pressure

The inlet pressure at which a pressure relief valve begins to open under service conditions; it may not exceed the vessel's maximum allowable working pressure.

Relief device test interval

The owner/user sets the interval, and API 510 limits it to a maximum of five years unless a documented basis, such as risk-based inspection, supports otherwise.

Set pressure tolerance

Bench test acceptance criterion: plus or minus three percent of set pressure above 70 psig, and plus or minus 2 psi at or below 70 psig.

Seat tightness test

A test performed after set-pressure adjustment, per API 527, confirming that leakage past the seat stays within the allowable bubble or flow limits for the device.

Block valve under PRV

Where permitted, inlet and outlet block valves must be locked or car-sealed open and full port, and their pressure drop included in relief capacity calculations.

Rupture disc

A non-reclosing pressure relief device; its burst rating and installation must be verified, and it is replaced at intervals established by the owner/user.

Repair definition

Work necessary to restore a pressure vessel to a condition suitable for safe operation at its existing design conditions, without changing any design parameters.

Alteration definition

A physical change with design implications, such as a change in MAWP, design temperature, material, pressure-retaining capability, or service that affects the rating.

Rerating

Changing a vessel's maximum allowable working pressure or design temperature; it requires engineering calculations, inspector concurrence, revised records, and new marking or nameplate.

Weld procedure qualification

Repair welds must follow a WPS qualified by procedure qualification testing under ASME Section IX, and welders must hold current performance qualifications.

PWHT alternative

Where postweld heat treatment is impractical, the engineer may approve alternatives such as controlled-deposition welding, verified by hardness testing and nondestructive examination.

Post-repair pressure test

Major repairs and alterations normally require a hydrostatic test at 1.3 times MAWP after completion, unless the inspector and engineer waive it based on the work performed.