The main equipment of the Φ180 mm 6-stand PQF three-roll stopper mandrel continuous rolling mill is composed of "conical roll piercer + 6-stand PQF continuous rolling mill + 3-stand de-piping machine + 14-stand micro tension setting machine. (reducing) diameter machine"; this unit mainly produces large diameter-to-wall ratio (D/S), high-quality petroleum pipes, product specifications are Φ114 ~ 180 mm × 4.0 ~ 22.0 mm, and the designed annual output is 500,000 t