The 31-year-old Swede of Iranian origin is being charged with trying to sell advanced valves to Iran through his company.
"He doesn't think he is guilty of crime," prosecutor Agnetha Hilding Qvarnström said.
The man stands accused of planning to circumvent international sanctions against Iran by first sending the equipment to Dubai.
The original charge sheet had said the export involved 11 walves, but that number now stands at two in the official charge, Qvarnström said.
Analysts say that the non-corrosive valves can be used in the oil and gas industry, but that the equipment is of such high quality that it is unlikely they would be used for anything but uranium enrichment.
Dual-use refers to technology that can be used in a nuclear programme even though it ordinarily employed in other industries.
Swedish customs officials discovered the shipment in 2011.
Iran has protested accusations that it aims to build a nuclear weapons arsenal by repeatedly stating that it runs a civil nuclear programme. The claim has failed to convince many observers in the international community
The country's economy is struggling to cope with punitive measures adopted by the US and the EU targeting its vital oil income and access to global financial systems.