STSI is certified, in accordance with the HRN EN ISO 3834-2 standard, for manufacturing and installation of pipelines and pressure vessels of category II, III and IV.
Tin the manufacturing plant in Sisak, there is a manufacturing workshop with a surface area of 3000 m2 that is equipped with three industrial cranes with a capacity of 5-10 t. The total capacity of the workshop is as follows:

• 40 pipe bundles per year (maximum dimensions – diameter 1,250 mm / length 9,000 mm / weight 20t)
• 10 pressure vessels per year (maximum dimensions – diameter 3,800 mm / length 12,000 mm / weight 20t)
• 20 air coolers per year (maximum dimensions – width 4,000 mm / height 1,400 mm / length 12,000 mm / weight 12t)
• 10 heat exchangers per year (maximum dimensions – diameter 1,200 mm / length 9,000 mm / weight 20t)

Applicable materials in accordance with the ASME and EN standards:

• carbon steel
• carbon steel for low and increased temperatures
• low-alloy steel for increased temperature
• high-alloy steel
• copper-titanium alloys.

Specialist staff at the Sisak site are the following:

• two EW engineers + one EW technician
• three engineers in production preparation
• two design engineers
• three persons authorized for NDT (UT, PT, VT, RT, MT)
• 6 welders
• 6 pipefitters
• 12 locksmiths.

Some of the machines used by STSI in manufacturing the equipment are the following:

• automatic ESSAB SAW welding machine
• sheet metal bending machine for thickness up to 50 mm
• sheet metal bending machine for thickness up to 25 mm
• CNC machining centre
• CNC pipe bundle cutting machine
• CNC press brake for angular bending of sheet metal
• CNC plasma/gas cutting machine
• Hydraulic scissors
• TIG, MMA, MIG/MAG welding machines
• positioning devices.