The NIBCO PVC DWV 22-1/2 elbow is used in residential and commercial drain, waste and vent systems. The PVC DWV 22-1/2 elbow features a hub x hub connection and is used to change the direction of flow. Polyvinyl chloride (PVC) is the most frequently specified of all thermoplastic materials because of its light weight, durability, and cost-effectiveness. Color: White.