Using B30 paktong tubes in condenser, especially in air extracting area, can significantly prevent condenser tubes from corrosion.
在凝汽器特别是空抽区，采用B_（30）白铜管可有效地防止凝汽器铜管的氨腐蚀。
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The results of scientific analyses of more than one hundred artefacts of Paktong presented in the book are also significant to further study of the history and technology of paktong…