Expansion tanks are pressure-bearing steel structures designed for offshore process and utility systems, used for pressure stabilisation and volume compensation in closed systems. The tank constitutes the pressure-stressed main unit of the expansion system. The tank can be supplied with an internal bladder or with direct contact with the liquid level combined with pressure control, depending on system requirements. The units are supplied in accordance with NORSOK requirements, oil companies' own specifications, and can, if required, be supplied approved according to the Norwegian Institute of Public Health's requirements for drinking water.

Typical design areas:

• Diameter: 1000–2000 mm
• Length / height: 1,500–3,000 mm
• Design pressure: 4–10 bar

Supplied as a standalone unit or integrated into process modules.