HG 20225《化工(gong)金(jin)屬管道工(gong)程施工(gong)及驗收規(gui)范》規(gui)定化工(gong)行業金(jin)屬管道應(ying)按管道所輸(shu)送(song)(song)的(de)(de)介質分為(wei)(wei)(wei)四類(lei)(lei)：A類(lei)(lei)為(wei)(wei)(wei)輸(shu)送(song)(song)劇毒介質的(de)(de)管道；B類(lei)(lei)為(wei)(wei)(wei)輸(shu)送(song)(song)可(ke)燃(ran)介質或有毒介質的(de)(de)管道；C類(lei)(lei)、D類(lei)(lei)為(wei)(wei)(wei)輸(shu)送(song)(song)非(fei)可(ke)燃(ran)介質、無毒介質的(de)(de)管道。其中設(she)計壓力p≤1MPa，且(qie)設(she)計溫度為(wei)(wei)(wei)-29～186℃的(de)(de)管道為(wei)(wei)(wei)D類(lei)(lei)管道。

   注(zhu)意：混合物料應以其(qi)主(zhu)導物料作為分級依據。常見劇(ju)毒介(jie)質、可燃介(jie)質或有毒介(jie)質，請參考(kao)《化工(gong)金屬管道工(gong)程(cheng)施工(gong)及驗收規范》的附(fu)錄(lu)。