The NIBCO 2 in. PVC DWV Hub x Hub P-Trap requires a primer before cementing. The PVC DWV P-Trap features a hub x hub connection and provides a water seal so that wastewater will automatically be trapped in the arc of the configuration, thereby preventing unwanted gases from entering the household environment. Polyvinyl chloride (PVC) is the most frequently specified of all thermoplastic materials because of its light weight, durability, and cost-effectiveness. Color: White.