Na Septemba 17, 2021, Ngalaba Azụmahịa US wepụtara ọkwa na-ekwupụta na a ga-emecha nyocha ikpeazụ nke ise mgbochi mkpofu ọkpọkọ nke ọkpọkọ ọkpọkọ carbon steel butt-welded (CarbonSteelButt-WeldPipeFittings) sitere na China, Taiwan, Brazil, Japan na Thailand ga-agwụcha. .Ọ bụrụ na akagbuo mpụ ahụ Ọrụ mgbochi mkpofu na nke a ga-eme ka a na-ekpochapụ ngwaahịa ndị metụtara ikpe ahụ na China na nkwụsị nke 182.90% ma ọ bụ ihe omume, ọnụ ọgụgụ nkwụsị nke ngwaahịa ndị metụtara ikpe ahụ. China ga-aga n'ihu ma ọ bụ mee, na mkpofu ngwaahịa ndị metụtara ikpe ahụ ga-aga n'ihu ma ọ bụ mee na ọnụ ọgụgụ mkpofu nke 87.30% na 52.25%.Mkpofu ngwaahịa ndị ahụ metụtara na ikpe ahụ gara n'ihu ma ọ bụ mee n'ọnụego mkpofu nke 65.81%, na ntupu nke ngwaahịa ndị metụtara na Thailand gara n'ihu ma ọ bụ mee na nbibi nke 52.60%.Ọ bụ 7307.93.30.

Na Disemba 12, 1986, United States manyere iwu mgbochi mkpofu na ọkpọkọ ọkpọkọ carbon steel butt welded sitere na Brazil na Taiwan, China.Na Febụwarị 10, 1987, United States nyere iwu iwu mgbochi mkpofu n'ọrụ ọkpọkọ ọkpọkọ carbon steel butt welded sitere na Japan., Na Julaị 6, 1992, United States nyere iwu iwu ọrụ mgbochi mkpofu zuru oke n'ọrụ ọkpọkọ ọkpọkọ carbon steel butt-welded nke malitere na China na Thailand.Kemgbe ahụ, US eduzila nyocha ọdịda anyanwụ 4, na Jenụwarị 6, 2000, Nọvemba 21, 2005, Eprel 15, 2011, na Ọgọst 23, 2011. Emere nkwenye na ọkwa ugboro anọ.usoro ahụ.Na Julaị 1, 2021, Ngalaba Azụmahịa US wepụtara nyocha na nyocha ọdịda anyanwụ ọdịda anyanwụ nke ise na-egbochi ikuku carbon steel butt-welded sitere na China, Taiwan, Brazil, Japan na Thailand.