Category
Materials, Welding & Coatings
Subcategory
Welding
Applicable standards
5
Issuing bodies
3
Description
WPS, PQR and welder performance qualification per ASME Section IX.
Applicable Standards (5)
API — 1 standard
API 582
Welding Guidelines for the Chemical, Oil, and Gas Industries
Supplementary welding requirements (PWHT, hardness, impact, NDE) beyond ASME IX.
Key requirements (7)
- Supplementary welding requirements for chemical/oil/gas industries — beyond ASME IX.
- Mandatory PWHT thresholds tighter than ASME VIII.
- Hardness limits: 200 HB (CS), 235 HB (1.25Cr-0.5Mo / 2.25Cr-1Mo) for sour service typical.
- Charpy impact requirements at MDMT for all weldments where production weld is impact-tested.
- PMI (positive material identification) required on alloy components.
- Hydrogen-induced cracking (HIC) prevention: low-hydrogen consumables, preheat, controlled diffusible H ≤ 8 mL/100g.
- Heat input control for impact-toughness-controlled materials.
ASME — 2 standards
ASME BPVC Sec IX
Welding, Brazing and Fusing Qualifications
Welding/brazing procedure and welder/operator qualification.
Key requirements (8)
- Welding and brazing qualifications.
- WPS (Welding Procedure Spec) supported by PQR (Procedure Qualification Record).
- PQR essential variables include: P-number, F-number, A-number, thickness range, position, preheat, PWHT, impact.
- Welder/operator qualification: bend tests OR radiography per QW-302.
- Coupon thickness qualifies a range: Table QW-451 (e.g., 25 mm coupon qualifies 5–50 mm).
- Position qualification: 6G qualifies all positions for pipe.
- Performance qualification expires if 6 months without welding (re-qualify).
- Notch toughness essentials when impact required by construction code.
ASME BPVC Sec V
Nondestructive Examination
NDE methods (RT, UT, MT, PT, ET, VT) referenced by Section VIII, B31.3, etc.
Key requirements (7)
- NDE methods: RT (radiography), UT (ultrasonic), MT (magnetic particle), PT (liquid penetrant), VT (visual), ET (eddy current), AE (acoustic emission), LT (leak).
- RT: density 1.8–4.0 (film), pixel density for digital.
- UT thickness: pulse-echo, accuracy typically ±0.1 mm.
- PAUT (phased array UT): increasing replacement of RT for thick welds.
- MT: residual or continuous magnetization, prods or yokes.
- PT: dwell time 5–60 minutes, developer dwell 7–30 min.
- Personnel certification: Level I/II/III per ASNT SNT-TC-1A or ISO 9712.
ISO — 2 standards
ISO 15614 (series)
Specification and qualification of welding procedures for metallic materials — Welding procedure test
Welding procedure qualification — international counterpart of ASME Sec IX.
ISO 9606 (series)
Qualification testing of welders — Fusion welding
Welder performance qualification (ISO).