Oil & Gas
Altbach HKW3: Fabrication and Installation of Alloy Steel Piping and Supports
Prefabrication, installation and testing of high-pressure alloy steel piping systems and supports (P91, P92, P22) for the Altbach HKW3 power plant in Germany.
For EnBW's Altbach HKW3 power plant in Germany, SEMAC fabricated, installed and tested high-temperature, high-pressure alloy steel piping systems (P91, P92 and P22) and their supports, on behalf of Sener Bonatti CCPP GmbH. The project ran from May 2025 to May 2026, in full compliance with German regulations, VGB, ANSI and the PED 2014/68/EU.
Prefabrication took place at our facilities in the Sindos Industrial Area: receipt and traceability of materials, cutting and bevelling of pipe ends, fit-up and welding to the project's IFC isometrics with qualified WPS/PQRs (ISO 15614, ISO 9606), and post-weld heat treatment (PWHT). Every spool was dimensionally checked, tagged and protected with sealed ends.
The piping was inspected with non-destructive testing (RT, UT, PT) and pressure tests, and the full documentation package — welding logs, NDT reports, material certificates and traceability records — was submitted for approval to the contractor and the notified body (NoBo). On site, our team also handled installation, heavy lifting, scaffolding and site management.
Scope of work
Mechanical works
Transport, unloading, positioning, alignment and installation of mechanical equipment Supply and installation of structural steel supports, anchor bolts, greasing components and protective elements Surface treatment and protective coating of equipment, piping and steel structures Detailed erection procedures, inspections and alignment checks
Piping systems
Complete prefabrication and erection of process and utility piping, including alloy steel grades P91, P92 and P22 Installation of valves, expansion joints, pipe supports and in-line components Welding with qualified WPS/PQRs in accordance with ISO 15614 and ISO 9606 Non-destructive testing (RT, UT, PT), and hydrostatic and pneumatic pressure tests Cleaning, flushing, preservation, pigging and air blowing of the completed piping networks
Fabrication at our facilities in Sindos, Greece
Receipt, identification and traceability of raw materials (pipes, fittings, flanges) Marking, cutting, bevelling, fit-up and welding to the project IFC isometrics PWHT, dimensional control, spool tagging and consumable traceability Weekly inspection and protection of fabricated items, including sealed spool ends Full documentation package — welding logs, NDT reports, material certificates and traceability records — for contractor and NoBo approval
Auxiliary and site services
Cranes, scaffolding, heavy lifting and transport equipment Surveying, topographic works and site logistics Site management, temporary facilities and material handling
Compliance and documentation
Execution in accordance with German regulations, VGB, ANSI, PED 2014/68/EU and other relevant international standards ITPs, erection drawings, QA/QC dossiers and as-built documentation Coordination with subcontractors, and integration into the HSE and quality assurance protocols
Photos and videos
9 photos · 1 video
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