First, what is the "basket"---a screen pack?? No need for screen packs in PVC pipe extrusion.
Assume you use a twin screw (almost all pipe made on twin screws). If so, your exit melt temp should be in the 380F-390F (180C) range, with screw oil temp and metering zone temp the same to get a smooth melt flow into the adapter,spider and die.
A wavy glossy ID could mean material is too hot----a dull rough ID to cold. A smooth semi-gloss is just right.
If using twin screw, use a "reverse" barrel temp. profile, hotter in the rear----like Z1-180C,Z2-170C, Z3-160C, Z4150C Screw oil-150C. Adapter-170, Spider-180, Die-190-195C.
This works best with "flood feeding"---material should be cheesy,semi fused at vent so a good vacuum can be pulled.
If material is fused and wrapped around screw at the vent, it is too hot---decrease Z1 &Z2.
Hopefully your lube system is balanced for your extruder.