Heavy fabrication & welding
First In Service fabricates and welds heavy steel structures in Tallinn, Estonia, up to 35 × 7 × 7 m (115 × 23 × 23 ft) and 160 tonnes (353,000 lb), certified to EN 1090-2 in execution class EXC3 and to EN ISO 3834-2. Processes cover 135/136, TIG and submerged arc welding to 100 mm in carbon steel, stainless steel, duplex, super duplex, Inconel and Hastelloy, all verified by NDT.
Heavy fabrication, sized for structures other workshops turn away.
We weld and fabricate large steel structures for offshore, marine, energy and defence applications. Every structure is built under EN ISO 3834-2 and EN 1090-2 quality systems, with full material traceability from raw stock to finished product.
Envelope
Welding processes
Materials
Surface treatment
Documentation
Specifications at a glance
| Maximum dimensions | 35 × 7 × 7 m (L×W×H) |
|---|---|
| Maximum weight | 160 tonnes (353,000 lb) |
| Workshop area | 18,000 m² (194,000 sq ft), Tallinn, Estonia |
| Lifting capacity | Up to 160 tonnes (353,000 lb) overhead |
| Processes | 135/136 (MIG/MAG), TIG, SAW |
| Penetration welding | Up to 100 mm |
| Standards | EN ISO 3834-2, EN 1090-2 |
| Steels | Carbon steel, stainless steel |
| Corrosion-resistant | Duplex, super duplex |
| Speciality alloys | Titanium, Inconel, Hastelloy |
| Preparation | Automated shot-blasting |
| Coating systems | Industrial anti-corrosion coatings |
| Material certificates | EN 10204 3.1, 3.2 on request |
| NDT | VT, PT, MT, UT via certified partners |
| Weld documentation | WPS/WPQR on request |
Questions procurement teams ask
What is the maximum size and weight for heavy fabrication?
Up to 35 × 7 × 7 metres (length × width × height) and 160 tonnes (353,000 lb), fabricated in our 18,000 m² (194,000 sq ft) Tallinn workshop.
What welding processes and standards do you use?
135/136 (MIG/MAG), TIG, and SAW with penetration welding up to 100 mm. Certified to EN ISO 3834-2 and EN 1090-2.
What materials can you weld?
Carbon steel, stainless steel, duplex, super duplex, titanium, Inconel, and Hastelloy.
Do you provide surface treatment for offshore and subsea components?
Yes. Complete surface treatment, from automated shot-blasting to industrial coating systems that meet NORSOK M-501 and corrosivity category C5-M.
What documentation ships with a fabricated component?
Material certificates (EN 10204 3.1, 3.2 on request), weld procedure documentation, and NDT reports (VT, PT, MT, UT) from inspections carried out by certified partners.
From drawing to dispatched structure
Every fabrication project starts with a Design for Manufacturability (DFM) review, not a price-per-kilo calculation. Our engineers check the drawing for weldability before quoting: weld access, distortion behaviour in thick sections, sequencing that keeps a 100-tonne structure within tolerance as it grows. If we see a detail that will cost you money in production — an inaccessible joint, a tolerance stack that fights the welding sequence — we flag it at the quoting stage, when changing it costs nothing.
Production follows a controlled sequence: material receipt with heat-number verification, cutting and edge preparation, fit-up with dimensional checks at each subassembly, welding under EN ISO 3834-2 procedure control, and post-weld NDT (VT, PT, MT, UT) performed by certified partners, so every critical weld gets an independent check. Surface treatment happens in-house: automated shot-blasting followed by coating systems built up to NORSOK M-501 or C5-M specification, with film thickness measured and logged per layer.
What leaves the workshop is a structure with its complete paper trail: material certificates matched to heat numbers, weld maps, NDT reports, dimensional protocols, and coating logs. Twenty kilometres later it is at Muuga Harbour.
Where this capability goes to work.
Marine, offshore & subsea
Thruster foundations, deck structures, subsea frames — coated for splash-zone service.
Marine, offshore & subsea →The same facility, with the evidence each sector asks for.
Rotating parts & shafts
Impellers, casings, rotors, shafts and turbine housings to ±0.02 mm (±0.0008 in).
Rotating parts & shafts →Mining & machine building
Crusher frames, conveyor structures and wear-resistant steel assemblies.
Mining & machine building →Buyer’s guides
What the welding certificate states
Transcribed from the certificates themselves, so every claim below can be checked against the issuing body.
Execution Class: Up to EXC 3 according to EN 1090-2. Welding processes 111, 131, 135, 136, 138, 141 acc. to EN ISO 4063.
Certificate no. 1526-CPR-1090-1.0173.TÜVEESTI.2023.001-WC · issuing body
Ready to discuss your project?
Send your drawings and specifications. We reply within 1 working day and send a firm quote within five working days.
Request a quoteBook a 20-minute call →Download capability overview (PDF)