The measure is part of an EU push against China, which makes more than half the world's steel, for allegedly flooding global markets in violation of international trade agreements.
It comes as protectionist US President Donald Trump promises to crack down on China's dominance of world trade, prompting a vigorous defense of globalisation by Chinese President Xi Jinping at the World Economic Forum in Davos last week.
"The European Commission's investigation confirmed that Chinese and Taiwanese stainless steel tube and pipe butt-welding fittings had been sold in Europe at dumped prices," the EU's executive arm said in a statement.
The EU has had a series of trade disputes with China, its second-largest trading partner, but is also seeking to resolve the stand-off over steel with Beijing through the OECD, the Paris-based group of developed economies.
Brussels now has more than 100 trade defence measures in place, 39 of them targeting unfair imports of steel products of which 15 are Chinese.