PVC flange types are classified by connection geometry and installation methodology, each influencing cost structure and suitability for particular pressure classes. The weld‑neck flange, comprising about 30 % of unit shipments, provides a tapered hub that is fully butt‑welded to pipe, delivering the highest strength‑to‑weight ratio for high‑pressure pipelines. Slip‑on flanges, representing roughly 25 % of the market, feature a flat face that slides over the pipe and is secured with fillet welding, offering rapid assembly for low‑to‑medium pressure lines. Threaded flanges, accounting for 20 % of sales, incorporate internal threads that mate directly with male‑threaded pipe ends, eliminating welding but limiting pressure capability. Socket‑weld flanges, at about 12 % of the mix, combine a socketed pipe insertion with a fillet weld, balancing ease of alignment with moderate pressure tolerance. Lap‑joint flanges (8 %) and blind flanges (5 %) serve specialized roles: the former enables quick removal for maintenance, while the latter caps dead‑end pipelines. Each type’s proportion reflects the engineering trade‑offs between installation speed, pressure rating, and lifecycle cost, thereby shaping the overall PVC flange market composition.