Cobalt-chromium Alloy http://www.cobaltalloy.net/ valve ball and seat are very important parts of underground oil-well pump , they always show up together and cooperate very good , no better material can replace Cobalt-chromium Alloy now .

The valve balls are made of Cobalt-chromium Alloy 20 and valve seat are made of Cobalt-chromium Alloy 3 . They are a good team to resist the wear and corrosion issue in oil and gas pimping process .