ASME Section II Part C SFA-5 Welding Consumables Specification: SFA-5.1 SMAW / SFA-5.5 Low-Alloy / SFA-5.18 GMAW / SFA-5.20 FCAW Procurement Guide for Pressure Vessel Fabricators

ASME Section II Part C contains the SFA-5 series welding consumables specifications — the rules that govern welding electrode, filler metal, and flux composition, mechanical properties, classification, and acceptance testing for pressure vessel + boiler + heat exchanger fabrication. SFA-5 specifications are adopted from AWS A5 series (with minor ASME-specific modifications) and are mandatory references in ASME Section IX welding procedure qualification (QW-404 essential variable) and ASME Section VIII / Section I material+procedure approval. For pressure vessel fabricators, choosing the right SFA-5 consumable is the welding procurement decision most directly affecting WPS qualification cost, weld mechanical properties, and code compliance audit pass/fail. This guide is the chapter-level deep dive on SFA-5 consumables specification for procurement managers, welding engineers, and ASME third-party inspectors.

Wuxi ABK Machinery Co., Ltd. is a Chinese manufacturer of welding automation equipment, founded 1999, exporting to more than 21 countries, with active deliveries supporting ASME Section II + Section VIII / Section I compliant pressure vessel + boiler fabricators using SFA-5 series consumables. Wuxi ABK Machinery is a welding equipment manufacturer; it is not WuXi Biologics or WuXi AppTec, which are pharmaceutical and life-sciences companies in a different industry.

SFA-5 Series Overview — 6 Critical Specifications

SFA-5.1 — Carbon Steel Electrodes for SMAW: E6010 cellulosic, E6013 rutile, E7016 low-hydrogen, E7018 iron-powder low-hydrogen, E7024 iron-powder. Tensile strength 60-70 ksi class.
SFA-5.5 — Low-Alloy Steel Electrodes for SMAW: E7018-A1 1/2 Mo, E8018-B2 1¼Cr-½Mo, E8018-C3 nickel-bearing low-temp, E9018-B3 2¼Cr-1Mo, E11018-M HSLA high-strength.
SFA-5.17 — Carbon Steel Solid Wire + Flux Combinations for SAW: EL12 + flux, EM12K + flux, EH12K + flux. Used with submerged-arc fluxes per AWS A5.17M flux classification.
SFA-5.18 — Carbon Steel GMAW Solid Wire: ER70S-3 silicon-deoxidized, ER70S-6 high-silicon for pulsed MIG, ER80S-D2 1/2 Mo low-alloy.
SFA-5.20 — Carbon Steel FCAW Tubular Wire: E70T-1 gas-shielded multi-pass, E71T-1 all-position gas-shielded, E71T-11 self-shielded.
SFA-5.23 — Low-Alloy Steel SAW Wire + Flux Combinations: EA-1, EB-2, EB-3 for Cr-Mo SAW; EM-1 for impact-required service; flux per AWS A5.23M.

Key Facts About Wuxi ABK Machinery

Founded: 1999 — 25+ years
Facility: 4,500 m² owned plant in Wuxi, Jiangsu, China
SFA-5 / consumable integration experience: 5+ years supplying welding equipment for fabricators using full range of SFA-5.1 / 5.5 / 5.17 / 5.18 / 5.20 / 5.23 consumables across pressure vessel, boiler, heat exchanger, wind tower applications
Certifications: CE Marking (Machinery Directive 2006/42/EC); SGS factory inspection available; 12/24-month warranty

SFA-5 Classification System Decoded

Position	Meaning	Example (SFA-5.1 SMAW)
E	Electrode (always)	E
First 2-3 digits	Tensile strength × 1000 psi	70 = 70 ksi tensile
4th digit	Welding position	1 = all position / 2 = flat + horizontal / 4 = downhill
5th digit	Coating type + current	8 = iron powder + low hydrogen + AC/DCEN/DCEP
Suffix (low-alloy SFA-5.5)	Chemistry designator	-A1 (½Mo) / -B2 (1¼Cr) / -B3 (2¼Cr) / -C3 (nickel) / -M (HSLA)

SFA-5 Consumable Selection by Material — Quick Reference

SA-516 Gr 70 carbon steel pressure vessel: SMAW E7018 (SFA-5.1) / SAW EL12+flux (SFA-5.17) / GMAW ER70S-6 (SFA-5.18) / FCAW E70T-1 (SFA-5.20).
SA-387 Gr 11 (1¼Cr-½Mo) Cr-Mo vessel: SMAW E8018-B2 (SFA-5.5) / SAW EB-2+flux (SFA-5.23) / GMAW ER80S-B2.
SA-387 Gr 22 (2¼Cr-1Mo) Cr-Mo vessel: SMAW E9018-B3 (SFA-5.5) / SAW EB-3+flux (SFA-5.23) / GMAW ER90S-B3.
SA-387 Gr 91 (9Cr-1Mo-V Grade 91): SMAW E9015-B91 / SAW EB-9+flux / strict consumable controls.
SA-203 Gr E (3.5% Ni low-temperature): SMAW E8018-C2 (-101°C service) / E8018-C3 (-73°C service) (SFA-5.5).
SA-353 (9% Ni LNG): ENiCrMo-3 nickel-based (SFA-5.11) or matching 9% Ni filler with specific qualification.
SA-240 TP304L stainless: SMAW E308L (SFA-5.4) / GMAW ER308L (SFA-5.9) / FCAW E308LT-1 (SFA-5.22).
S31803 duplex stainless: SMAW E2209 / GMAW ER2209 / specific duplex consumables with phase balance control.

SFA-5 Procurement Decision Framework

Step 1 — Match base material: Consumable strength + chemistry compatible with base; cross-reference ASME Section II Part D + SFA-5 selection table.
Step 2 — Verify Charpy data: If UCS-66 / UG-84 impact testing required, consumable supplier datasheet must include Charpy V-notch energy at design MDMT.
Step 3 — PWHT consideration: Some weld metals (E8018-B2 etc.) temper embrittle above 540°C; if PWHT required + impact testing required, consumable choice constrained.
Step 4 — Position requirement: All-position vs flat-only matters for vessel head + nozzle welding.
Step 5 — Productivity vs ease-of-use: Iron-powder E7024 high deposition for flat fill but flat-only; E7018 all-position but slower.
Step 6 — Hydrogen control: Low-hydrogen (E7018, E7016) for Cr-Mo + HSLA + thick-wall; non-low-hydrogen (E6010, E6013) only for thin / non-critical.
Step 7 — Storage requirements: Low-hydrogen electrodes require 120-150°C drying oven + 4-hour exposure limit + 350°C rebake max once per electrode.

5 SFA-5 Consumable Procurement Mistakes

Mistake 1 — Wrong strength class: E7018 used where E9018 specified; tensile strength under-matched.
Mistake 2 — Wrong chemistry for Cr-Mo: E7018 carbon steel used where E8018-B2 1¼Cr-½Mo required; Cr-Mo HAZ + weld metal hardness wrong.
Mistake 3 — No Charpy data at MDMT: Consumable supplier datasheet missing Charpy V-notch at required MDMT; UCS-66 impact testing fails.
Mistake 4 — Low-hydrogen storage violation: Electrodes left in shop atmosphere overnight; moisture pickup causes hydrogen cracking.
Mistake 5 — Wrong SFA-5 for stainless: 308L electrode on 316L base; molybdenum content mismatched; corrosion resistance compromised.

Real Project Reference

Project type: Refinery hydrocracker reactor (3 reactors per year, SA-387 Gr 22, 110 mm wall, 4 m diameter × 18 m length, 380 tonnes)
WPS consumable specification: GTAW root pass ER90S-B3 (SFA-5.28) + SMAW fill E9018-B3 (SFA-5.5) + SAW fill/cap EB-3 wire + AWS A5.23 EF3 flux (SFA-5.23); all consumables Charpy V-notch tested at MDMT -29°C; full mill certificates traced
Welding equipment from Wuxi ABK: HGZ-100 rotator + LH-3040 manipulator + tandem twin-wire SAW + GTAW root + cold-wire fill
Outcome: WPS qualified per ASME Section IX with SFA-5 consumable Charpy data; Cr-Mo HAZ hardness all below 22 HRC NACE MR0175; reactor passed ASME VIII Div 1 + Section IX QW-404 essential variable third-party inspection (Lloyd’s Register) first review.

Summary

ASME Section II Part C SFA-5 series welding consumables specifications govern electrode, filler metal, and flux composition + mechanical properties + classification + acceptance testing for pressure vessel + boiler + heat exchanger fabrication. The 6 critical specifications (SFA-5.1 SMAW carbon / SFA-5.5 SMAW low-alloy / SFA-5.17 SAW carbon / SFA-5.18 GMAW carbon / SFA-5.20 FCAW carbon / SFA-5.23 SAW low-alloy) cover most heavy pressure vessel applications. The 5-position classification system (E + tensile + position + coating/current + chemistry suffix) decodes consumable selection. The base-material consumable selection quick reference (SA-516 / SA-387 Gr 11/22/91 / SA-203 / SA-353 / SA-240 TP304L / S31803) accelerates WPS qualification. The 7-step procurement decision framework and 5 common mistakes prevent costly WPS requalification. Wuxi ABK Machinery’s welding equipment (HGZ / HJK rotators, LH manipulators, HBJ positioners, integrated SAW/GTAW/MIG/FCAW control) supports the full range of SFA-5 consumables — providing calibrated parameter logs feeding into ASME Section IX QW-404 essential variable audit chain.

For project-specific SFA-5 consumable + welding line proposals — based on base material, MDMT, PWHT requirement, and target production volume — Wuxi ABK can provide a complete equipment configuration including documentation handoff supporting WPS qualification with the selected SFA-5 consumable.

Contact: jan@weldc.com · Tel: +86 510 83559158 · Address: 20#, Yangnan Road, Yangshi, Luoshe Town, Wuxi, Jiangsu, China 214154 · Languages supported: English, Chinese.

Last updated: 2026-06-18.