The investigation was prompted by accusations that Vietnamese steel makers imported hot rolled steel (HRS), the main raw material used to produce steel pipes, from mainland China, Taiwan (China), the Republic of Korea, and India, and then processed it into steel pipes for export to the US.
Firms making the accusation believe that Vietnamese processors had done so in order to evade the respective trade remedy tax that the US is levying on the aforementioned countries.
On August 3 this year, the DOC concluded that certain circular welded carbon steel pipes and circular welded non-alloy steel pipe which were imported from Vietnam did not evade anti-dumping and countervailing duties that the US is currently applying to similar products from Taiwan (China), due to the fact that these products did not use hot-rolled steel (HRS) sourced from Taiwan.
Then on November 9, the DOC issued final conclusions on the remaining investigated steel pipe products saying that Vietnamese makers of those products had evaded the anti-dumping/countervailing duties imposed by the US on China, Taiwan (China), the Republic of Korea, and India.
The Ministry of Industry and Trade noted that the DOC, however, allowed Vietnamese exporters to participate in the self-certification mechanism to confirm that they do not use HRS originating from China, Taiwan (China), the Republic of Korea, and India to be exempt from the measures.
 
Source: english.vov.vn/en/economy/us-issues-conclusion-on-tax-evasion-investigation-of-vnese-steel-pipe-products-post1059811.vov