For PVC pipe manufacturing, a conical twin-screw extruder is generally preferred over a single-screw extruder, especially for rigid PVC pipes. In a pvc pipe manufacturing plant machine list, the extrusion line usually includes a high-speed hot and cold mixer, conical twin-screw extruder, die head, vacuum calibration tank, cooling tank, haul-off machine, cutting machine, and pipe stacking unit. The twin-screw extruder is important because it provides proper mixing, melting, and uniform processing of the PVC compound before it enters the die. This helps maintain consistent pipe dimensions, smooth surface finish, and stable production. A single-screw extruder can also be used for some PVC applications, but a twin-screw extruder is commonly selected for rigid PVC pipe production because it offers better material mixing and processing control. The die head determines the pipe profile and diameter, while the vacuum calibration tank helps maintain the required size and shape after extrusion.