The dark grey PVC socket flange features a female socket connection. The Van Stone flange assembly includes a connector hub, PVC coated aluminum flange ring and a PVC flange ring. Chemtrol® fittings connect PVC piping lengths together with solvent cementing, threading or flanging to create a highly reliable, leak-free system. Please refer to Chemtrol technical data sheets, chemical resistance guides and catalogs for engineering and installation information. PVC Schedule 80 has the highest long-term hydrostatic strength of any other major thermoplastic material used for piping. Chemtrol® PVC fittings are lightweight, easy to install, maintenance-free, and will not rust, scale, pit or corrode. Chemtrol® premium line of plastic fittings is backed by a 1-year limited warranty. Because Chemtrol® is a NIBCO brand the flow-control fittings are unsurpassed in quality, performance and longevity.