The dark grey PVC threaded union features female pipe thread connections. This fitting has an EPDM ethylene propylene seal which has good abrasion and tear resistance, plus excellent chemical resistance, but not recommended for applications involving petroleum oils or most strong acids. 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.