AWS NDE Coordination flashcards

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

RT IQI sensitivity

Image quality indicator sensitivity is measured by the smallest wire or hole visible; required sensitivity is typically 2% of material thickness, with T-1, T-2, T-3 hole types by thickness range.

UT near field length

The near field length N equals D squared divided by four times wavelength; it defines the distance over which the beam is collimated before diverging.

PT dwell time

Penetrant dwell time is typically 10 to 15 minutes; developer dwell time is also 10 to 15 minutes; excess penetrant must be removed carefully to avoid over-washing.

MT field strength

Magnetic particle inspection requires a field strength of 30 to 60 gauss for the continuous method, verified with a field indicator, and particle concentration of 0.1 to 0.4 mL per 100 mL.

NDE method selection

Surface-breaking flaws are detected by PT or MT; volumetric flaws by RT or UT; austenitic welds need UT with dual-element or phased array; thick sections may need Co-60 or linear accelerator RT.

ASME UW-51 acceptance

ASME Section VIII Division 1 UW-51 radiographic acceptance rejects any crack, incomplete fusion, or incomplete penetration; rounded indications are limited by size and density charts.

NDE personnel qualification

Personnel are qualified per ASNT SNT-TC-1A or CP-189; Level II must be employer-certified; Level III is required for procedure approval and interpretation of results.

NDE hold points

Hold points are root pass, back-gouge, and final weld; inspection must be coordinated with welding and QA before closing; rejected results generate a nonconformance report.

RT film density

Radiographic film density for X-rays is typically 1.8 to 4.0, and for gamma rays 2.0 to 4.0; density outside this range may require re-shooting.

UT beam spread

Beam spread half-angle is given by sine theta equals 1.22 times wavelength divided by transducer diameter; smaller diameter or higher frequency changes spread.

PT developer application

Developer is applied as a thin, uniform coat after penetrant removal and drying; it draws penetrant from surface discontinuities to form visible indications.

MT particle concentration

Particle concentration in the bath is checked with a centrifuge tube; acceptable range is 0.1 to 0.4 mL per 100 mL of bath for fluorescent particles.

RT source selection

X-ray tubes are used for thin sections; gamma sources such as Ir-192 for medium thickness and Co-60 for thick sections; selection depends on thickness and code requirements.

UT calibration block

Calibration blocks such as IIW or ASME basic block are used to set velocity, delay, and sensitivity; calibration is verified at start and end of inspection.

NDE report content

NDE reports include method, procedure, personnel, equipment, calibration, acceptance criteria, results, and disposition; they must be signed and traceable.

Visual inspection (VT)

Visual inspection is the primary method for weld surface condition; it checks for cracks, undercut, overlap, spatter, and dimensional compliance before other NDE.

Welding procedure qualification

A PQR per ASME Section IX records essential variables such as process, base metal P-number, filler F-number, position, preheat, and PWHT; changes require requalification.

Welder performance qualification

A WPQ per ASME Section IX QW-300 qualifies a welder; essential variables include process, position, backing, and filler; continuity is maintained by a 6-month log.

Carbon equivalent formula

CE equals C plus Mn/6 plus (Cr+Mo+V)/5 plus (Ni+Cu)/15; a CE above 0.4 generally requires preheat to avoid cracking.

PWHT requirements

Post-weld heat treatment is required for P-1 carbon steel over 32 mm thick; hold at 595 to 690 degrees Celsius for one hour per 25 mm; cooling rate limited below 425 degrees.

Weld inspection sequence

Inspection sequence is fit-up, root pass, fill passes, and final weld; visual inspection is performed at each stage; NDE follows final weld and repair requires re-inspection.

QA documentation package

The QA package includes WPS, PQR, WPQ, NDE reports, heat treatment charts, material test reports, and nonconformance reports; all must be traceable to the weld.

Distortion control methods

Distortion is controlled by balanced welding sequence, back-step, skip welding, pre-setting, and restraint; dimensional checks monitor compliance.

Code compliance verification

ASME Section IX covers qualification; Section VIII covers vessels; AWS D1.1 covers structural; API 1104 covers pipelines; verify WPS and PQR alignment before production.

Preheat purpose

Preheat slows cooling rate, reduces hydrogen cracking risk, and improves fusion; minimum preheat is specified by code based on thickness and carbon equivalent.

Essential variables

Essential variables are conditions that, if changed, require requalification of the WPS or WPQ; examples include process, position, preheat, and PWHT.

WPS content

A WPS specifies process, base metal, filler, position, preheat, current, voltage, travel speed, and PWHT; it must be supported by a qualified PQR.

PQR test coupon

The PQR test coupon is welded per the proposed WPS and tested by mechanical methods such as tensile, bend, and impact to qualify the procedure.

Welder continuity log

A welder's continuity log records that the welder has used the process within a 6-month period; lapse requires requalification.

Repair welding procedure

Repair welding follows a qualified WPS; excavated area is inspected before repair; repair is re-inspected by the same or equivalent NDE method.

Material test report

The MTR provides chemical and mechanical properties of the base metal and filler; it is checked against specification and traceability requirements.

Heat treatment chart

A heat treatment chart records temperature versus time during preheat or PWHT; it verifies compliance with the code-required cycle and is part of the QA record.