The refinery underwent fundamental overhaul for 25 days. The overhaul ended on Thursday.

The overhaul covered the distillation unit in the vacuum and atmospheric conditions, the LPG unit, part of sulfur manufacturing and coking and the steam and gas power plants of the utility units. It also covered three boilers with 145 tons capacity an hour, a boiler in the same capacity in northern refinery at a cost of more than 40 billion rials.

While overhaul of the distillation unit was going on, a 7.2 megawatt power generator and a ECO set were installed on boilers of one of the northern refineries.

The non-catalyst units undergo an overhaul every four years and technical engineers carefully check the system in terms of erosion and corrosion.

The southern distillation unit of Tehran Refinery runs with daily 125,000 barrels capacity and latest count of overhaul of the distillation unit dates as back as 2012.

The overhaul plays an important and preventive role in checking eruption of unwanted incidents.

Tehran refinery includes two refinery sections: Refinery no. 1 and Refinery no. 2.

Owing to domestic needs to petroleum products, construction of Tehran refinery no. 1 was launched in 1968 and finished off in 1971. Initial nominal capacity of refinery no. 1 was 85000 BPSD which increased to 125000 BPSD after process debottlenecking project in 1976.

In response to the rising consumption rate of petroleum products and to meet the domestic market demands, second refinery with nominal capacity of 100000 BPSD was established in 1973. Similarly, in 2003 nominal capacity of this refinery was increased to 125000 BPSD. The feed of both refineries is provided by two 24 and 26 inch pipeline from south oil fields of Maroon Ahvaz, Saraje Qom and Middle Asian countries.