Industrial Welding

What this service is

Certified fusion welding for industrial process systems, pressure equipment, and structural elements — delivered on site or in prefabrication. Our crews handle the full welding scope from root pass to final cap, including weld preparation, fit-up, preheat, inter-pass monitoring, and documented traceability.

We work to ISO 3834-2 comprehensive quality requirements. Our welders are qualified under EN ISO 9606-1 and our procedures are qualified under EN ISO 15614-1 with full WPS/WPQR documentation available on request.

Scope

Included:

• Weld preparation and fit-up
• Root, fill, and cap passes in positional welding (1G through 6G)
• Pre-heat and inter-pass temperature control where required by WPS
• Tacking, cleat and lug welding for structural assemblies
• Repair welding on existing installations
• Welder-to-WPS mapping and on-site documentation
• Daily log sheets and weld numbering per client requirement
• Handover with full weld traceability package

Not included (by default, available separately):

• Radiography (RT) — coordinated with approved NDT partners
• Ultrasonic (UT / PAUT) — coordinated with approved NDT partners
• Post-weld heat treatment — arranged via subcontract on request
• Material supply — client-supplied unless agreed otherwise

Codes and standards we work to

• ISO 3834-2 — Quality requirements for fusion welding of metallic materials (comprehensive)
• EN 1090-1 / EN 1090-2 — Execution of steel structures, CE marking
• EN ISO 9606-1 — Welder qualification testing (steel)
• EN ISO 14731 — Welding coordination tasks and responsibilities
• EN ISO 15614-1 — WPS qualification via procedure test
• EN ISO 5817 — Quality levels for imperfections
• ASME B31.1 — Power piping (where project requires)
• ASME B31.3 — Process piping (where project requires)
• PED 2014/68/EU — Pressure Equipment Directive compliance

Where a project requires additional or client-specific codes (NORSOK M-601, AWS D1.1, DNV-OS-C401, etc.), our welding coordination can adapt existing WPS coverage or qualify new procedures within standard project timelines.

Materials

We weld the full European industrial material range:

• Carbon steel — ISO/TR 15608 groups 1.1 (non-alloy) and 1.2 (fine-grained C–Mn). Common grades include P235GH, P265GH, P295GH for pressure applications; S235, S275, S355 for structural.
• Austenitic stainless — group 8.1. Common grades 304, 304L, 316, 316L, 321, 347. Root-pass purging per client specification.
• Duplex stainless — group 10.1. Grade 2205 for corrosion-resistant service. Strict heat input and inter-pass temperature control per WPS.
• Alloy and nickel-based — group 7 and adjacent. Welded on project-specific qualification where client scope requires.

Thickness range: 1 mm to 60 mm in standard execution. Thicker sections accepted on request with multi-pass and pre-heat strategy agreed upfront.

Welding processes

Our welders typically hold multiple qualifications across these processes so that crew composition can be matched to the weld scope without reshuffling.

Diameter and thickness range

• Diameter: DN25 (instrument and small process piping) through DN2000 (large-diameter prefabrication)
• Wall thickness: 1 mm to 60 mm in standard execution
• Schedule coverage: SCH 10 through XXS where relevant

The low end of this range is the same TIG precision you’d expect on instrument tubing. The high end is what we delivered on Stegra’s green steel facility — heavy-section carbon steel pipe sections for industrial process lines.

NDT readiness

Our welds are prepared for the full non-destructive testing cycle. NDT itself is coordinated with approved partners on each project:

• VT — 100% visual testing, in-house, per EN ISO 17637
• PT — liquid penetrant, in-house capability
• MT — magnetic particle, partnered
• RT — radiographic testing, coordinated with client-approved NDT company
• UT and PAUT — coordinated with client-approved NDT company

We maintain compliant weld preparation, surface condition, and marking so that NDT acceptance rates are predictable and rework is minimized.

Where we’ve delivered this service

• St1 Refinery, Sweden — furnace turnaround welding in confined and hard-to-access areas across three consecutive campaigns
• Stegra (H2 Green Steel), Sweden — large-diameter carbon steel prefabrication DN25–DN2000
• S.M.I Lorraine, France — welding restoration during heat exchanger overhaul

→ See all 9 projects

Frequently asked

Do you hold EN 1090 certification? Yes. MIDAS is certified under EN 1090-1 and EN 1090-2. Certification details including body, number, and valid-until date are published on our certifications page.

Can you work to ASME B31.3? Yes. We have procedure qualification and welder experience for process piping under ASME B31.3. Project-specific WPS will be issued or referenced in the RFQ response.

How do you handle welder qualification renewals? Our welding coordination maintains an active register of welder qualifications with renewal dates. Welders whose qualifications are within 30 days of expiry are prevented from being deployed to critical welds. Full register available under NDA for prequalification review.

What’s your typical inter-pass temperature control procedure? Per WPS, using contact pyrometer readings logged on daily sheets. On duplex and sensitized-material jobs, temperature limits are enforced by the on-site welding supervisor who signs off each pass before continuing.

Do you handle purge welding on stainless root runs? Yes. Argon back-purging to oxygen content targets specified by client WPS, typically below 50 ppm for critical applications. Purge dams, oxygen analyzers, and purging gas supply managed by our crew.

Can you provide a welding coordinator on site? We operate under EN ISO 14731 welding coordination framework. A designated welding supervisor is assigned to every project with the required experience level for the work’s technical risk class. For projects requiring a formal IWE/IWT/IWS-credentialed coordinator, we coordinate with client-side or partner welding engineering as needed.

Request a quote

Send us your scope, WPS package, drawings, and standards. We’ll respond within one business day with team composition, qualification matching, and mobilization plan.

CTA: Request a Quote Secondary: Send Us Your WPS / Drawing Package