Product Description PVC Threaded Riser uPVC Class 7 " and " PVC extended nipples (pipe risers) have male threaded connections and are rated to 10 bar. Our 1" extended nipples (pipe risers) are formed from cut lengths of Class 7 PVC tube and threaded both ends to BS EN10241 (formerly BS1387). . Available in 6 Sizes " x " BSP x 150mm " x " BSP x 300mm " x " BSP x 500mm " x " BSP x 150mm " x " BSP x 300mm " x " BSP x 500mm