AWS NDE Coordination cheat sheet

RT sensitivity: image quality indicator (IQI) essential wire diameter vs. 2% of material thickness; T-1 hole IQI for thickness ≤ 6.4 mm, T-2 for > 6.4 to 19 mm, T-3 for > 19 mm.

UT: near field length N = D²/(4λ) and beam spread half-angle sin θ = 1.22 λ/D; inspect in far field where possible; use 6 dB drop method for length sizing.

PT dwell times: penetrant 10–15 min, developer 10–15 min; excess penetrant removed with water rinse or solvent; do not over-wash.

MT: field strength 30–60 gauss for continuous method; particle concentration 0.1–0.4 mL per 100 mL of bath; verify with a field indicator.

NDE method selection: surface-breaking flaws → PT/MT; volumetric flaws → RT/UT; austenitic welds → UT with dual-element or phased array; thick sections → RT with Co-60 or linear accelerator.

Acceptance: ASME Section VIII Div. 1 UW-51 radiographic acceptance - no cracks, no incomplete fusion/penetration; rounded indications limited by size and density charts.

Personnel qualification: ASNT SNT-TC-1A or CP-189; Level II must be certified by employer; Level III required for procedure approval and interpretation.

NDE hold points: root pass, back-gouge, final weld; coordinate with welding and QA before closing; document with NCR if rejected.

Welding procedure qualification: PQR per ASME Section IX; essential variables include process, base metal P-number, filler F-number, position, preheat, PWHT; changes require requalification.

Welder performance qualification: WPQ per ASME Section IX QW-300; essential variables include process, position, backing, filler; continuity maintained by 6-month log.

Preheat: carbon equivalent CE = C + Mn/6 + (Cr+Mo+V)/5 + (Ni+Cu)/15; CE > 0.4 requires preheat; minimum preheat per ASME Section VIII Table UW-2 or code.

PWHT: required for P-1 carbon steel > 32 mm thickness; hold at 595–690°C for 1 h per 25 mm; cooling rate ≤ 55°C/h below 425°C.

Weld inspection sequence: fit-up, root pass, fill passes, final; visual per AWS D1.1 or ASME; NDE per code; repair welding requires re-inspection.

QA documentation: WPS, PQR, WPQ, NDE reports, heat treatment charts, material certificates (MTR), and NCRs; maintain traceability.

Distortion control: balanced welding sequence, back-step, skip welding, pre-setting, and restraint; monitor with dimensional checks.

Code compliance: ASME Section IX for qualification; Section VIII for vessels; AWS D1.1 for structural; API 1104 for pipelines; verify WPS/PQR alignment before production.