Cryogenic tanks in Iran

Foundations with seismic insulators to build two double-wall steel tanks, a 32,000-cubic-metre tank for stocking ethylene and an 18,000-cubic-metre tank for stocking ethane in the OLEFIN PLANT of “South Pars Oil and Gas Field” (IRAN).

These are insulated double-wall steel tanks; the tank for ethylene storage is made of a cylindrical inner wall of diameter 37 metres and height 29.8 metres and a cylindrical outer wall of diameter 39 metres and height 31.8 metres. The tank for ethane storage is made of a cylindrical inner wall of diameter 32.6 metres and height 24.5 metres and a cylindrical outer wall of diameter 32.6 metres and height 26.5 metres.

The peculiarity of this project is the need for seismic insulation of the tanks, due to the particularly high seismic risk of the site.

For this purpose, the reinforced concrete circular platforms 80 cm thick supporting the tanks are designed to be supported on damped pendulum seismic insulators made of two steel spherical cap surfaces separated by a sliding piece, with a friction suitable to damp the oscillatory energy. Totally, 190 insulators are foreseen under the ethylene tank and 113 are foreseen under the ethane tank.

Each insulator is supported by a column, and the columns are bound to underground circular platforms 120 cm thick, supported at a depth of about 2.5 m; the columns and the lower platforms are foreseen in reinforced concrete.

Service provided: Preliminary design for bid.

Client: PARESA S.p.A.

Site: OLEFIN PLANT in “South Pars Oil and Gas Field” (IRAN).

Year: 2018.

Cost of works: about 22 million Euros