Oil & Gas
HELLENiQ PETROLEUM Thessaloniki Industrial Installations: Mechanical & Electrical Works
Multi-year framework agreements with HELLENiQ PETROLEUM for mechanical, electrical, instrumentation and fire-protection works at the Thessaloniki refinery.
SEMAC Construction is a contractor to HELLENiQ PETROLEUM (HELLENiQ ENERGY Group) at its Thessaloniki Industrial Installations, under five multi-year framework agreements for mechanical, electrical, instrumentation and fire-protection works. We work every day inside an operating refinery, where safety, quality and fast response come first.
We cover the full extent of the refinery: process units, utilities, tank farms, product handling and loading, substations and control rooms. Our permanent crews are based inside the installations and are reinforced at short notice when needed.
We work across all of the Thessaloniki installations: the N. Ionia industrial complex (the refinery), the Kalochori and Paralia installations, the islet and anchorage, and the pipeline corridor, as well as pipeline networks outside the installations throughout the Thessaloniki region.
Industrial Piping
Prefabrication, erection and modification of process and utility piping, from 1/4″ to 36″.
Carbon steel, alloy steels (P11, P22, P5, P9), stainless steels (304, 316, 321, 347), Hastelloy and cement-lined pipe Flanged joints up to 30″ in classes 150 to 600 lb and above, NPT threaded joints and dissimilar-metal welds Underground piping up to 24″, with coating & wrapping and holiday testing Steam tracing, manifolds and sample coolers Hot tapping: connections to live lines and tanks, from 1/2″ to 16″ Hydrostatic testing of circuits, flushing and chemical cleaning, valve testing to API 598
Steel Structures
Supply, fabrication, blasting, painting and erection of steel structures, and modifications to existing ones.
Pipe racks, platforms, walkways and access structures Stairs, caged ladders and handrails Gratings and canopies Standard and special pipe supports, and installation of spring hangers
Mechanical Equipment Erection
Installation of rotating and static equipment, from pump alignment to column internals.
Pumps, compressors, blowers and fans, with alignment (including hot alignment) and installation of mechanical seals Columns, vessels, reactors, heat exchangers, air-cooled exchangers (air fins) and stacks Column internals: trays, grids, cyclones, demisters and packing Dismantling of equipment and piping, catalyst unloading
Welding & QA/QC
Qualified procedures and welders, non-destructive testing and full material traceability.
Welding procedures (WPS/PQR) and qualified welders (WPQ) to ASME IX / API 1104 Radiographic (RT), ultrasonic (UT), penetrant (PT) and magnetic particle (MT) testing, hardness testing and positive material identification (PMI) Post-weld heat treatment (PWHT) up to 30″ Inspection and test plans (ITP), QA/QC and weld maps
Electrical Installations
Medium- and low-voltage installations, from cabling and substations to equipment in hazardous areas.
Power, control and instrument cables up to 400 mm², fibre optics with termination and certification, data networks Medium voltage (6 kV and 20 kV): joints, terminations, substation connections, MCCs and alarm panels, insulation and VLF testing Cable trays, conduits, earthing and lightning protection Indoor and outdoor LED lighting, pole-mounted road lighting, emergency lighting Hazardous areas (ATEX Zone 1 & 2): explosion-proof luminaires and sockets, motor control stations, explosion-proof cable glands, electrical heat tracing Fire detection systems: panels, detectors, beacons and sounders
Instrumentation & Control
Installation, testing and calibration of instruments and analysers, through to commissioning.
Flow, level, pressure and temperature instruments, panel- and field-mounted Oxygen, pH, conductivity, moisture, TOC, oil-in-water and other analysers Instrument air tubing Loop checks and commissioning Calibration of instruments, control valves, safety valves and analysers
Fire Protection
Repair and maintenance of the refinery's permanent fire-fighting equipment.
Replacement and overhaul of fire hydrants Repair of fixed and wheeled fire monitors Replacement of 4″–12″ valve-pit valves on the fire-water network Maintenance of hose stations and hose reels Machining: seat build-up and turning, parts made to sample
Turnarounds & Maintenance
Work during unit shutdowns and immediate response to emergencies.
Participation in the refinery turnarounds (shutdowns), with multiple crews working around the clock, including public holidays Immediate mobilisation for emergencies, with a technical supervisor available 24/7
Blasting, Painting & Insulation
Blasting and painting of equipment, piping, steel structures and buildings to the client's specifications, with dry film thickness (DFT) checks Thermal insulation of equipment, piping and valves, with rock wool and aluminium cladding
Support Works
Excavation and backfilling, including vacuum excavation near underground services Duct banks and cable trenches, pits, foundations and asphalt reinstatement Tube-and-fitting and suspended scaffolding, including above 10 m Lifting with cranes up to 200 t, with lifting plans
Engineering & Documentation
Isometric, layout and steelwork drawings As-built drawings in AutoCAD Small electrical studies, such as protection selectivity studies
Safety in a Refinery Environment
Daily work permits, following the client's procedures for hot work, isolations (blinds, lock-out/tag-out) and work on operating units Work in confined spaces, at height and in hazardous areas (H₂S, explosive atmospheres) A safety engineer, certified technicians and electricians, and staff with refinery safety training Waste management in line with the client's environmental procedures
Standards & Specifications
Mechanical: ASME, API, ANSI, ASTM, TEMA, EN, ISO, PED Welding: ASME IX, API 1104 Electrical: ATEX (2014/34/EU), IEC 61439, EN 54, CE marking The client's company specifications and Global Practices
Our Contracts at the Thessaloniki Installations
Call-off mechanical works: piping, equipment, steel structures, NDT/PWHT, scaffolding Call-off mechanical works for the Engineering & Construction Department: new construction and modifications, including insulation and painting Call-off electrical and instrumentation works: MV/LV electrical, lighting, ATEX, instruments, automation Repair of permanent fire-fighting equipment: hydrants, monitors, valve-pit valves, hose stations Electrical works for the new Diesel Export pumping station: electrical tie-in of the new pumping station
Featured Job: Electrical Tie-in of a New Diesel Pumping Station
New pumping station with 6.3 kV medium-voltage motors and motor-operated emergency isolation valves, connected to two substations and the control room About 1.4 km of MV, LV, control and fibre-optic cable routes Construction of cable trenches and pits Installation of explosion-proof (ATEX) control stations Medium-voltage terminations, VLF testing and as-built drawings
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