TEHRAN -- For the first time, Iranian experts have updated a distributed control system (DCS) built by U.S. industrial conglomerate Emerson Electric at a petrochemical plant in the southwestern port of Mahshahr.
Distributed control systems are computerized platforms for automated control and operation of a plant or industrial process, usually with many control loops, in which autonomous controllers are distributed throughout the system.
The Emerson DCS used at the Shahid Tondgooyan Petrochemical Company (STPC) was obsolete, which had caused major production problems at the plant’s PET 1 unit, the company said in a statement.

The U.S. company’s refusal to cooperate and provide support because of the American sanctions prompted Iranian experts to revamp and update the system without laying off production units, it added.
For the update, the system needed a year to be programmed for upgrade, after which the production units had to be shut down in order to incorporate the new application into the DCS.
“After the programming, due to the commitments of the STPC and the vital and important role of its products in different industries of the country, it was not practically possible to stop all units in order to run the new program,” the company said.
“So, the closure of production units separately was assessed and approved, as a result of which no disruption occurred in the company’s commitments to support national production,” it added.
Earlier this month, the STPC said Iranian experts had designed and built a rotary air compressor which it badly needed in its polyethylene terephthalate (PET) unit but could not import because of U.S. sanctions, Press TV reported.