HG 20225《化工(gong)金屬管(guan)(guan)(guan)道(dao)(dao)工(gong)程施(shi)工(gong)及驗收規(gui)范》規(gui)定(ding)化工(gong)行業(ye)金屬管(guan)(guan)(guan)道(dao)(dao)應按管(guan)(guan)(guan)道(dao)(dao)所輸(shu)(shu)送(song)的(de)(de)(de)介(jie)質(zhi)(zhi)(zhi)分為四類(lei)(lei)(lei)：A類(lei)(lei)(lei)為輸(shu)(shu)送(song)劇(ju)毒(du)介(jie)質(zhi)(zhi)(zhi)的(de)(de)(de)管(guan)(guan)(guan)道(dao)(dao)；B類(lei)(lei)(lei)為輸(shu)(shu)送(song)可燃(ran)介(jie)質(zhi)(zhi)(zhi)或(huo)有(you)毒(du)介(jie)質(zhi)(zhi)(zhi)的(de)(de)(de)管(guan)(guan)(guan)道(dao)(dao)；C類(lei)(lei)(lei)、D類(lei)(lei)(lei)為輸(shu)(shu)送(song)非可燃(ran)介(jie)質(zhi)(zhi)(zhi)、無毒(du)介(jie)質(zhi)(zhi)(zhi)的(de)(de)(de)管(guan)(guan)(guan)道(dao)(dao)。其中設計壓力p≤1MPa，且設計溫度為-29～186℃的(de)(de)(de)管(guan)(guan)(guan)道(dao)(dao)為D類(lei)(lei)(lei)管(guan)(guan)(guan)道(dao)(dao)。

   注意：混合物料應以(yi)其主導物料作為分級依據。常(chang)見劇毒介質、可燃介質或有毒介質，請參考《化工金屬管道工程施工及驗(yan)收規(gui)范(fan)》的附錄。