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Bronze valves and brass valves are mainly made of different materials. Copper has corrosion resistance, long service life, and higher prices. The difference is several times. For example, for a gate valve, a copper core means that the smooth sealing surface is copper, just a small circle. For a DN100 gate valve, that circle is only two fingers wide, and the thickness may be 3mm. In other places, there is a copper or iron sleeve, and everything else is iron. Copper valves, except for the screw rod, are all copper.