... gas,water,oil,etc 4.SDR11/SDR17 HDPE pipe fittingHDPE Butt fusion flange adapter/stub FittingsSize From ... 20mm---500mm Our HDPE fittings including Electrofusion Fittings,Butt fusion Fitting ... Socket Joint Fitting,PE Ball Valves Fittings,PE/Steel Transition Fittings,etc. Including Reducer,,Coupler,Reducing ... and competitive price9. SDR11/SDR17 hdpe pipe fitting with flange