Used in chemical pipes.Reinforced pipe joint (type SW, A flat bottomed)DN25X300 20# JB4726 SW flat bottomed 40T025/01 SCH80What do you mean by that?
20# steel, JB 4726-2000 material "pressure vessel with carbon steel and low alloy" standard, SW socket welding. ?40T025/01 is drawing number, SCH80 diameter specifications. See below;
DN means the inner diameter, 25 is 25mm, and DN25 is "25 mm in diameter", length 300mm.
D means "diameter", and "n" means "internal" (because pinyin is "Nei" in "inner")
